There is a rapidly growing body of literature on mobile video calling, which is a promising communication technology; however, little research has focused on user acceptance of mobile video calling, especially in different use contexts. This study explored factors  influencing the intention of users to employ video calling in different contexts (a work and a leisure context) by applying the technology acceptance model (TAM) combined with the theory of planned behavior. The revised research model differentiated external factors  from internal factors , perceived enjoyment, and intention to use mobile video calling). In addition, the current study investigated predictors of perceived enjoyment across these two contexts. With the use of a structured questionnaire, participants were divided in two groups and completed self-report measures related to one context; a total of 386 student respondents’ responses were analyzed. The results indicated that users’ intentions were directly predicted by their perceived enjoyment of video calling (β ≥ 0.35) and the call’s perceived usefulness (β ≥ 0.27) and PEU , which jointly explained at least 55.6% of the variance in use intention. In addition to the effects of these predictors on mobile video calling use acceptance, an assessment of the moderating effects of different contexts indicated that perceived enjoyment played a more important role in influencing intention for the leisure context, while perceived usefulness appeared to be more important for the work context. This study’s findings are important in that they provide strong support for the necessity of distinguishing among different types of contexts when predicting users’ intentions to use video calling. Furthermore, the results showed that perceived enjoyment was most significantly influenced by perceived usefulness (β ≥ 0.61), followed by PEU (β ≥ 0.13). In summary, the roles of core TAM variables  and of external factors  differed between the leisure and work contexts. The implications of these findings are discussed. Mobile value-added services  have become an important resource that creates revenue for business providers. One of these companies’ aims is to attract new subscribers and retain old ones. With the development of telecommunication technologies (such as 4G and LTE) and smart phones, certain new and important mobile value-added services continue to attract people who use cell phones to communicate via video calling. For example, Juniper Research forecasted that video calling  users alone are expected to increase by over 130 million by 2018. This figure does not include messaging, push-to-talk or audio calling options . RecentlAlthough telecommunications firms in China have been committed to solving technical issues to offer better technical support for the use of video calling, why has this service not been more widely accepted? With the growing popularity of smart phones and the development of wireless network technology in mobile phones, those support technologies can be realized. Under these circumstances, video calling has naturally become a new opportunity for telecom service providers to generate revenue. Information and communication technology (ICT) firms are trying to capture a competitive edge and greater market share in video calling and related markets. However, it is unclear how they can attract customers. Consumer acceptance is probably the main factor driving the diffusion of video calling. Video calling is an attractive technology, as users can make video calls with friends and family during leisure time and use it for video conferencing during work hours. Therefore, reliably identifying and understanding factors affecting consumers’ behavioral intention to use this service in different contexts has become a key issue.From the perspective of consumer demand, telecommunications providers have a vested interest in understanding the behavior of video call users. A significant body of theoretical research has focused on media, technology, and service acceptance behavior by applying the theory of reasoned action (TRA) , the theIn the current study, we used the TAM as a theoretical framework, adding belief elements from the TPB to examine users’ acceptance of video calling technology in leisure and work contexts. In the following sections, we review empirical studies focusing on user acceptance and then identify research hypotheses.In terms of understanding users’ decision to use technology, several theoretical models have been widely applied in previous studies. The earlier related model of the TRA assumes that beliefs affect behavior; it is a well-known model for predicting the intention to perform a behavior based on an individual’s attitudinal and normative beliefs . Then, tBased on the TRA, Having comprehensively considered the various theories, this study generally used the TAM as its basic theoretical foundation while including the beliefs of the revised TPB as external variables. Previous research has successfully integrated the TPB into the TAM to investigate technology acceptance behavior . The curAccording to the TAM and the TPB, several important internal and external factors affect consumers’ intention to adopt video calling services: perceived usefulness, PEU, perceived enjoyment, subjective norms, and personal innovativeness. Furthermore, different contexts of use should be considered a crucial factor to be investigated.Perceived usefulness and PEU, as the TAM’s primary factors, determine users’ acceptance or rejection of ICT . PerceivHowever, previous studies have indicated that perceived usefulness and PEU cannot fully explain consumers’ behavioral intentions to use a new technology . ResearcAnother important issue is related to the relationship among perceived enjoyment, perceived usefulness, and PEU. In the original version of the TAM, generally perceived usefulness has a more powerful effect than PEU in predicting behavioral use intention, and perceived usefulness also mediates the effect of PEU on user acceptance . Some prCollectively, regarding mobile video calling use acceptance, the above concerns led to the following hypotheses:H1.Perceived usefulness would have a positive influence on the perceived enjoyment of video calling usage in addition to having a direct impact on users’ behavioral intention to use mobile video calling.H2.Perceived ease of use would have a positive influence on the perceived enjoyment of video calling usage.H3.Perceived enjoyment would have a positive influence on users’ behavioral intention to adopt mobile video calling.H4.Perceived usefulness and perceived enjoyment would jointly determine the behavioral intention to use mobile video calling.According to the TRA and TPB, subjective norms reflect how consumers are affected by their perception that those who are important to them think that they should (or should not) perform a given behavior . As the Another important individual variable is personal innovativeness, which is defined as an individual’s willingness to try out any new technology . PersonaSince the role of perceived enjoyment in the acceptance of video calling was investigated in this study, the predictive effects of subjective norms and personal innovativeness on using this mobile service may also be moderated through perceived enjoyment. Thus, when considered as a whole, TAM-based studies indicate that the above-mentioned variables from the TAM and the TPB should significantly affect consumer acceptance and usage of video calling. That is, the external variables are strongly interrelated according to the TAM. The corresponding hypotheses regarding subjective norms and personal innovativeness that were tested in this study are as follows:H5.Subjective norms positively would affect users’ perceived enjoyment and use decisions regarding mobile video calling.H6.Personal innovativeness positively would affect users’ perceived enjoyment and use decisions regarding mobile video calling.Most previous empirical studies based on the TAM were based on voluntary contexts, and all the participants using the new technology were voluntarily participating in leisure contexts . HoweverThe core variables  in the TAM are consistent with basic measures of user experience. For example, to consolidate the definitions in usability community, the International Organization for Standardization (ISO) defined usability as “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.” That is, user perception and acceptance of technology can mean different things to different people in different specific use contexts. In an earlier study, As a motivational variable, users’ enjoyment perception tends to be more dependent on use context. Some previous studies considered perceived enjoyment to be a focal aspect of entertainment media usage because individuals consume these media primarily to seek fun or pleasure . HoweverClearly, the motivations and feelings of users who use these technologies in different contexts differ. Correspondingly, the degree to which different factors influence customers’ acceptance of these technologies will also vary. As a new type of information communication technology, video calling has characteristics oriented toward both entertainment and work. Additionally, potential users can either use cell phones to make video calls with friends and family during their leisure time or for video conferencing during work time, implying that the degree to which the varying factors affect users’ behavioral intentions may differ in different contexts. However, few previous studies related to video calling have focused on investigating how different situations affect users’ video calling acceptance based on the TAM. Therefore, this study proposed considering the different contexts (work contexts and leisure contexts) to investigate the ways in which different contexts influence users’ acceptance of video calling technology. The corresponding hypothesis was proposed as follows:H7.The degree to which perceived enjoyment affects behavioral intentions to use mobile video calling would vary in different user contexts, i.e., work contexts and leisure contexts.Figure 1.Thus, these proposed hypotheses generated the research model described in Following a method used in previous studies adopting the TPB that encourages respondents to answer questions in a relatively natural way, two potential use contexts were generated, both including the same written introduction regarding video calling services. One context depicted a situation in which the respondents use video calling to contact a colleague for work purposes. The second context depicted a situation in which the respondents used video calling to contact a friend for leisure purposes.The written introduction read as follows:Since the issuing of 4G licenses and the completion of 4G networks, 4G mobile value-added services have become increasingly popular, including “video calling,” which is one of the typical services offered by telecommunications businesses. As the name suggests, cell phone video calling services enable both sides of the conversation to see each other smoothly and clearly in real time. Currently, when using a mobile phone to make video calls, both sides need to place a cell phone in front of them so that the phone’s camera can relay images of both users.The contexts were as follows:•Work ContextSuppose you currently have a position in a company located in a city that has established a 4G network and that you are currently using a 4G mobile phone that is able to support video calls. It is a weekday morning, and you are working. You need to use the phone to call a colleague to address a work-related issue. Your colleague’s cell phone also supports video calls. When you call, you can choose conventional talk mode  or video call mode.•Leisure ContextSuppose you currently have a position in a company located in a city that has established a 4G network and that you are currently using a 4G mobile phone that is able to support video calls. It is a weekend morning, and you are looking over photos you have previously taken. At this point, you remember that it is time for you to contact a friend, and you are ready to use the cell phone to call him or her to say hello. Your friend’s cell phone also supports video calls. When you call, you can choose conventional talk mode  or video call mode.A self-administered questionnaire was developed based on existing scales, using minor wording modifications to fit items into the two different contexts. Following each context, and in line with previous studies on mobile service use decisions, participants responded to a series of items constructed based on an extended TAM questionnaire . All items designed for the above measures were presented to the respondents in random order. Following the context-specific questions, respondents responded to questions about subjective norms and personal innovativeness , and they completed several demographic measures . Respondents rated each item measuring the standard and extended components of the TAM on 7-point unipolar scales ranging from 1 (a negatively scored statement) to 7 (a positively scored statement).Behavioral intention was assessed by calculating the mean score of the following four items : “In theFollowing a method used in previous studies , the meaPrevious studies have also examined the perceived enjoyment of the use of mobile-data services. In line with these studies , 2004, tIn line with previous studies using the TAM framework , a direcPrevious studies have also examined subjective norms. In line with these studies , the meaFollowing a method used in previous studies , the meaDemographic information, including age, gender, city of residence, specialized subject of study, service provider, and expenditure on mobile services per month, was also collected.SD = 1.5); 188 respondents were male (51.1%), and 180 were female (48.9%). In terms of specialized subject of study, 19.6% of the respondents reported that they specialized in human and social sciences; those studying some type of art accounted for only 3.3%. Most of the respondents specialized in management (38.6%) or science and technology (37.8%). Regarding service providers, most subjects reported using China Mobile (90.5%), while China Unicom and China Telecom represented only 4.6 and 3.8% of reported providers, respectively. In terms of expenditure on mobile services per month, almost 12.8% of users spent less than 30 Yuan; 34.8% spent between 30 and 50 Yuan; 26.9% spent between 31 and 70 Yuan; and the remainder (25.5%) spent more than 70 Yuan.In terms of gender and city of residence, the respondents were approximately balanced. A total of 386 students who were potential users of video calling participated in the study; however, 18 (4.7%) were eliminated due to incomplete or non-sensical responses. The subjects of the survey were university students from Beijing and Beihai, China. The two context-specific questionnaires were randomly distributed to the participants. Nearly half of the respondents from each city were asked to complete the questionnaire about the work context, and the other half from each city were asked to complete the questionnaire about the leisure context. Among the 368 respondents who provided valid responses, 182 respondents answered the questions regarding the work context , and the remaining 186 respondents answered the questions regarding the leisure context . Thus, the responses to each context-specific questionnaire were nearly equal. For the 368 valid responses, the subjects were between the ages of 17 and 26 years, with an average age of 20.9 years  of the measured variables were higher than the criterion (0.50) and that the CR values for all the constructs were above the recommended level of 0.70. These results indicate that the scales had good reliability. Table 3) for each construct is higher than its correlations with the other constructs. Table 3 shows that all of the square roots of the AVE for each construct were higher than the correlations, indicating that the discriminant validity was acceptable. Overall, the validity and reliability of the questionnaire were acceptable.According to Table 3. Regarding the different contexts considered overall, the means of the scales indicate that respondents had a slightly positive intention to use video calling (M = 4.83), perceived the behavior to be somewhat enjoyable (M = 4.89), perceived this behavior as being of moderate usefulness (M = 4.73), perceived that the service should be easy to use (M = 5.10), felt social approval from important others (M = 5.04), and reported a medium degree of personal innovativeness (M = 4.43). All of the research model variables were found to positively correlate with each other in both situations. Gender was not associated with most of study variables, with the exception of negatively correlating with PEU in the work context.The means and zero-order correlation coefficients for the various measures, organized by context type (work or leisure), are shown in F = 4.51, p < 0.05, η2 = 0.01], perceived that the technology should be more enjoyable  and perceived that video calling should be easier to use  in the leisure context. There were no significant differences in perceived usefulness , subjective norms , or personal innovativeness  between the work and leisure contexts.To validate the study’s hypotheses, one-way analyses of variance were used to test whether the intention to use, along with other TAM variables, differed between the contexts (work and leisure). Compared with the work context, respondents were more likely to make a video call , with both original predictors having a significant influence on predicting the intention to use video calling. In step 3, perceived enjoyment, when added to the regression analysis, was able to explain an additional 7.5% of the variance, resulting in a significant increase to 57.7% , and all three TAM variables emerged as significant predictors . In step 3, the extended TAM variables were able to explain an additional 3.8% of the variance in using video calling , with subjective norms and personal innovativeness having a moderately limited but statistically significant independent effect, along with perceived enjoyment and perceived usefulness. In this step, the influence of PEU on behavioral intention disappeared.Considering the leisure context, in step 1, the two original TAM predictors  were able to explain 50.20% of the variance in behavioral intentions , with both variables  emerging as significant predictors. When added to the regression analysis in step 2, perceived enjoyment resulted in a substantial increase to 55.6% in the variance in using mobile video calling , with perceived enjoyment and perceived usefulness emerging as very significant predictors. The effect of PEU weakened to the point of non-significance. In step 3, when the extended TAM variables were added to the regression equation, they were able to explain only an additional 0.40% of the variance . Subjective norms and personal innovativeness did not emerge as significant predictors along with PEU.In the work context, in step 1, the original TAM variables were able to explain 50.1% of the variance in mobile video calling [Overall, in the context of work, perceived usefulness was a strong determinant of intention to use video calling, and perceived enjoyment was a significant secondary determinant. By contrast, for potential leisure usage, perceived enjoyment was the strongest predictor and perceived usefulness become a secondary predictor. In addition, the context mediated the predictive power of PEU and the two extended variables , which tended to have a moderate or small independent effect on the intention to use video calling in the leisure situation only.Table 5.To address the effects of the two original TAM variables and the two extended TAM variables on perceived enjoyment and to test the corresponding hypothesis, a two-step hierarchical regression analysis was conducted to investigate the utility of the predictors, especially perceived usefulness and PEU, for perceived enjoyment. For each of the two contexts, perceived usefulness and PEU were entered in step 1, and the extended variables of subjective norms and personal innovativeness were added in step 2. By controlling for the influence of other variables, this approach allowed us to test the associations between perceived enjoyment and other study variables. The results are summarized in Table 5, in step 1, the two original TAM variables resulted in substantial and significant counts, representing 63.0% and 55.4% of the observed variance in the leisure and work contexts , respectively. Perceived usefulness  and PEU  emerged as very significant predictors in both contexts. For both contexts, as presented in step 2, the extended TAM variables, when added to the regression equation, only increased the variance by an additional 1.7%, and subjective norms emerged as a weak significant predictor  . However, personal innovativeness tended to be a weak significant predictor in the leisure context only . All of these findings indicated that perceived usefulness had a greater influence on mobile video calling than PEU. Furthermore, there were limited differences in the degree to which various factors affected behavioral intentions for different contexts (the work and leisure contexts), except for the influence of personal innovativeness.As shown in The goals of this research were to examine the factors influencing users’ intention to use video calling , as well as to distinguish the influence of different contexts (the work context and the leisure context) on predicting user acceptance of this service. The data collected from participants were utilized to test the proposed research model. The results showed that users’ intentions were directly determined by perceived usefulness and perceived enjoyment, and the proposed research model explained 56.0% and 61.5% of the total variance in users’ intentions in the work and leisure contexts, respectively. In addition, there were some context-specific differences in predicting user acceptance of mobile video calling.From the perspective of user acceptance, we examined the effects of perceived usefulness, PEU, perceived enjoyment, subjective norms, and personal innovativeness on mobile video calling via the proposed research model. The results of this research indicated that perceived enjoyment could be considered a core predictor along with perceived usefulness in predicting users’ intentions toward mobile video calling, especially for the leisure context.In line with our expectations, hypotheses 1 and 3 were confirmed. Perceived enjoyment and perceived usefulness emerged as significant predictors of the intention to use mobile video calling. This finding is consistent with the findings of prior TAM-based studies e.g.,  indicatiRegarding practical implications, perceived enjoyment, as an added factor in the basic structure, exerted a significant effect on users’ intention to use mobile video calling in both contexts. Therefore, to enhance consumers’ behavioral intention to adopt mobile value-added services, such as video calling, perceived enjoyment should be the primary focus. This finding suggests that in a specific context, users’ motivation to use a mobile value-added service is derived from the enjoyment of using the service. Mobile video calling services offer visual and interactive functions, including the convenience of enabling people on both sides to watch dynamic images on the screen and experience the good feelings that result from communicating. Furthermore, these services offer the benefit of being cost-effective for potential customers. These rich features of mobile value-added service can provide customers with a more pleasant experience. Therefore, the entertaining and enjoyable content provided by video calling services can be treated as an important factor determining the acceptance of this service. In summary, to enhance consumers’ behavioral intention to use video calling, providers do not need to convey a great deal of technical information to consumers when promoting value-added services; instead, they should consider focusing on improving consumers’ perceived enjoyment of this technology.The results of the current study show that the perceived enjoyment of using video calling is significantly affected by perceived usefulness, indicating that users’ perception of usefulness is a key determinant of perceived enjoyment levels, which is in line with hypothesis 1. Thus, according to hypothesis 4, perceived usefulness influences intention in two ways: directly and indirectly via perceived enjoyment. Furthermore, PEU is positively related to perceived enjoyment. These findings are consistent with hypothesis 2. In addition, subjective norms emerged as a weak significant predictor of perceived enjoyment in both the work context and the leisure context. This finding supports hypothesis 4 to some extent. According to our research, the improvement of perceived enjoyment depends on increases in perceived usefulness, PEU and subjective norms in general. Providers attempting to attract consumers to use this service can increase users’ satisfaction by improving the usefulness of the technology and by making the video call interface easier to operate, both of which can directly affect users’ behavioral intention to adopt video calling. Additionally, improving public perceptions of the technology and encouraging more users to adopt video calling services may cause users to perceive greater social approval from important others. Thus, consumers will be more willing to use this technology and obtain more enjoyment when doing so.In the current study, perceived enjoyment was the most important predictor of users’ intention to use video calling in the leisure context, while perceived usefulness was the most important predictor in the work context. Additionally, perceived enjoyment and perceived usefulness had different roles regarding the context. Our results revealed that context-specific differences influenced users’ video calling acceptance, which supports hypothesis 7. For example, perceived usefulness and perceived enjoyment jointly determined the behavioral intention to use video calling in both the work context and the leisure context. However, in the work context, the role of perceived usefulness was more important for explaining users’ behavioral intentions than perceived enjoyment was. By contrast, perceived enjoyment had a more powerful effect on behavioral intentions in the leisure context. In addition, the predictive effect of perceived usefulness on perceived enjoyment was stronger in the work context than in the leisure context. However, the effect of PEU on perceived enjoyment was weaker in the work context than in the leisure context. These important findings indicate the necessity of distinguishing between different contexts (the work context and the leisure context) when predicting user acceptance of video calling. These results are consistent with those of previous studies . Users’ Thus, to attract more consumers to video calling services and to reduce the cost of developing video calling technology, providers in the telecommunications industry should consider developing two different usage context patterns for video calling. Technology development could be better targeted to consumers’ different demands in different contexts. For instance, the effect of perceived enjoyment was greater in the leisure context than in the work context. Therefore, developers should pay more attention to the recreational design of video calling, adding more attractive entertainment elements when developing technology for the leisure context. In interactive video chat, for example, they might add the effect of a dynamic figure to express the behavior of kissing by showing a cartoon kiss in the video call screen. By contrast, providers should devote more attention to improving the practicality of video calling technology and help users improve task performance for the work context, where perceived usefulness is more important. Additionally, the work context design may need to be more formal in appearance. Because the video call interface is easy to operate on users’ mobile devices, users are not overly concerned about PEU in the work context. However, in the leisure context, users consider PEU: the less effort users need to expend in learning to use video calling, the more willing they will be to use it in the leisure context.This study investigated consumers’ behavioral intentions to adopt a specific mobile value-added service: video calling. The following conclusions were reached. First, as the results of this study show, perceived enjoyment is one important factor directly impacting consumers’ behavioral intention to adopt video calling technology. The perceived enjoyment of using video calling is significantly affected by perceived usefulness, followed by PEU. In particular, the predictive effect of perceived usefulness on perceived enjoyment is stronger in the work context than that in the leisure context. However, the effect of PEU on perceived enjoyment is weaker in the work context than in the leisure context. Second, the intention to use video calling services is primarily determined by perceived usefulness and perceived enjoyment. In the work context, perceived usefulness has a stronger predictive effect on the intention to use video calling. By contrast, perceived enjoyment has a more powerful effect on behavioral intention in the leisure context. Third, as external variables, subjective norms and personal innovativeness both have a very limited influence on perceived enjoyment and on the intention to use video calling. Finally, the degree of the effect exercised by all of the reliable factors on the intention to use video calling differs in different contexts. Users in the leisure context expressed a stronger intention to use video calling services, in addition to demanding greater ease of use and a higher level of enjoyment in using value-added video calling services, compared with users in the work context.The limitations of this study are as follows. First, the subjects were university students from Beijing and Beihai, China, which means that the results could not be generalized to all consumers. Second, unlike in Western countries, the 4G telecom service market in China is still under development and the costs are relatively high. Thus, a sampling of all the practical users of mobile value-added services was not available. Third, as a result of time constraints, only cross-sectional data were analyzed. The extent to which current behavioral intention to use video calling can be used to predict future behavior is unknown. Because a longitudinal research method could not be adopted, prudence was required in the discussion of causal relationships between constructs. In the future, when consumers have a higher level of involvement in mobile value-added services, studies in this field could undertake in-depth investigations to allow more objective conclusions. Additionally, this study primarily investigated the endogenous variables  affecting behavioral intentions. Follow-up studies could examine more external variables affecting the adoption of mobile value-added services, such as personality traits. External variables, especially personal innovativeness, should be considered along with a combination of personal traits. For instance, personality traits (such as the Big Five) could also be relevant important predictors in determining users’ social network sites, which are a typical interpersonal technology e.g., . To obtaConceived and designed the experiments: RZ. Performed the survey: RZ. Analyzed the data: RZ. Wrote the manuscript: RZ and CF.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Neuromarketing has become popular and received a lot of attention. The quality of video commercials and the product information they convey to consumers is a hotly debated topic among advertising agencies and product advertisers. This study explored the impact of advertising narrative and the frequency of branding product exposures on the preference for the commercial and the branding product. We performed electroencephalography (EEG) experiments on 30 subjects while they watched video commercials. The behavioral data indicated that commercials with a structured narrative and containing multiple exposures of the branding products had a positive impact on the preference for the commercial and the branding product. The EEG spectral dynamics showed that the narratives of video commercials resulted in higher theta power of the left frontal, bilateral occipital region, and higher gamma power of the limbic system. The narratives also induced significant cognitive integration-related beta and gamma power of the bilateral temporal regions and the parietal region. It is worth noting that the video commercials with a single exposure of the branding products would be indicators of attention. These new findings suggest that the presence of a narrative structure in video commercials has a critical impact on the preference for branding products. Whether video commercials can successfully promote products has been a focus of attention in the industry and in academia24We attempted to clarify the significance of the narrative and of the frequency of branding product exposure in video commercials. The experiment utilized the presence of the narrative and the frequency of branding product exposure in the video commercial as independent variables. We considered the audience’s response, as measured by preference for the video commercial and the branding product, and branding product awareness. This study aimed to explore the effects of the “narrative” and the “frequency of branding product exposure” on the audience’s preference for the video commercials and the branding products.The concept of a “narrative” originated from literary theory679Barthes proposed that the application of narrative structure can be expanded to non-verbal creations6We found that video commercials mostly use a set of visuals to form a story to present a branding product“Advertising narrative” has been studied by researchers in the fields of marketing and psychology. The manners in which the plot and the script structure affect consumers’ gradual understanding of the branding product are discussed. In addition, researchers try to increase the audience’s attention in order to better convince consumers using advertising1516171820212324By understanding the consumer’s needs, marketers set communication goals and desired effects262730The use of EEG analysis to explore the effect of advertising has been frequently adopted in recent years323436373839During the cognitive stage of watching video commercials, the parietal region receives sensory stimuli and messages from different brain regions5et al. also found that enhanced theta band activity in the frontal lobe is associated with positive emotions and subjective preference decisionset al. found that the observation of emotional commercials may increase activity in the orbitofrontal region and the amygdalaDuring the affective stage, the emotions and feelings brought on by the video commercials in the audience affect the preference decision for the commercials5In this study, the views of the consumers or the audience were used to explore controversial issues. The narratives of video commercials and the frequency of branding product exposure were used to explore the EEG dynamics of cognitive integration and the consumer’s preference decision for the advertising stimulus. The stimuli and the experimental design are shown in We studied the two independent variables narrative structure and branding product exposure. We classified the commercials into four types of stimuli based on these variables . IndepenA one-way ANOVA was performed to compare the effects of the four different types of stimuli generated using the two independent variables . The braAn independent samples t-test was also performed to assess video commercial preference . The resA one-way ANOVA was performed to compare the effects of the four types of stimuli based on the two independent variables . The preDifferences in spectral power in various brain regions are summarized in The cognitive integration-related regions for the 2 independent variables were located in the temporal and parietal regions . The powAdditionally, we observed that the power of the theta oscillations generated during video commercials with a narrative structure was significantly higher than those induced by videos with no narrative structure (p = 0.000). The power of the beta oscillations in the parietal region during video commercials with a single exposure was significantly higher than those generated during videos with multiple exposures (p = 0.04).Previous studies have indicated that activity in the frontal region, the bilateral occipital region, and the limbic system is related to preference decisions. In this study, the results of the influence of the narrative structure on the left frontal region (BA 9) and the bilateral occipital region (BA 31) indicated that the theta power generated by narratively structured video commercials was significantly higher than that generated by commercials without a narrative structure  . The betWe found that the branding products in the video commercials stimulated delta and gamma rhythms in the frontal midline region BA 32, . The froThe quality of video commercials and the product information they convey to consumers is a hotly debated topic among advertising agencies and product advertisers. Analyses of behavioral data indicate that the narrative structure of a video commercial has an impact on preference for the branding products and video commercials. In the case of video commercials, the presence of a narrative structure led to the most significant difference. NS-ME commercials were the most favored among the audience and the corresponding products were also the most popular. The least favorite video commercials were NNS-ME commercials. This suggests that the presence of a narrative structure has a critical impact on video commercial preference among the audience.et al. carried out EEG experiments of art appreciation and concluded that the brain region affected by figurative artwork was different from the region affected by abstract artwork. When the artwork was relatively figurative, or when style information was provided, there were significant activities in the bilateral temporal regions. On the other hand, when the artwork was relatively abstract, or when no style information was provided, the frontal region, especially on the left side, exhibited relatively strong EEG activityThe EEG results indicate that the presence of a narrative structure generates differences in brain activity in regions responsible for cognitive integration. As can be seen in Narrative structure influenced cortical activity in decision-making-related regions. In the limbic system, the gamma power produced by narratively structured video commercials was higher than that produced by non-narratively structured video commercials. The limbic system consists of the orbitofrontal cortex, insular cortex, anterior and posterior cingulate cortices, parahippocampal gyrus, hippocampal formation, amygdala, basal forebrain, and hypothalamuset al., who found the same significant theta and beta band activities in their study on the preference for visual stimulationNarratively structured video commercials produced significant theta power in the left frontal region. This is consistent with previous findings showing that theta power in the left frontal region is associated with pleasant video commercials and is also related to emotional engagementAnalysis of behavioral data showed that the frequency of branding product exposure in the video commercial had no significant impact on video commercial preference, but was able to influence the degree of preference for the products. Most likely, the sense of the presence of the branding products enhances the consumers’ preference for them. EEG analysis revealed that the frequency of exposure may produce significant differences in theta power in the cognitive integration-related right temporal and parietal regions, and that the theta power produced by video commercials with multiple exposures was higher than that produced by video commercials with a single exposure. It is speculated that multiple exposures in video commercials can influence cognitive integration. However, the effect sizes of the significant differences are not as large as those associated with narrative structure. Not many preference decision-related brain regions showed significant differences associated with branded product exposure. We only found differences in the right occipital region, but not in other regions. This suggests that our findings may be associated with visual stimulation.et al. found that the enhanced gamma band activity in the frontal region was related to perception switchinget al. found that the 40 Hz gamma band is associated with transient attentionBranding product exposure is associated with significant differences in the frontal delta and gamma rhythms. These findings are related to perception switching and attentionIn this study, higher alpha power was observed in the bilateral occipital region when the participants watched NNS-ME video commercials (p < 0.01), while lower alpha power was found in the same region while NS-ME video commercials were displayed. Previous studies have shown that occipital alpha rhythms are related to visual perceptionThis study found that, (A) The presence of a narrative had a significant positive correlation with preference scores of the branding products and the video commercial. (B) The impact of branding product exposure on the preference for the branding products and the video commercials was in effect conditional; the single factor, frequency of exposure only had a significant positive impact on preference for the branding product and had no significant impact preference for the video commercial. The behavioral data obtained during exposure to the four groups of stimuli produced by combining two variables reveal that preference for the branding products requires an interaction between narrative structure and multiple exposures to branded products. This finding was also confirmed by the EEG results. Narratively structured video commercials led to higher preference decision-related theta power in the left frontal region, theta and beta power in the bilateral occipital region, and gamma power in the limbic system. They also induced significant cognitive integration-related beta and gamma power in the bilateral temporal regions and theta, beta, and gamma power in the parietal region. It is believed that narratively structured video commercials can produce high levels of brain activity related to the preference decision and cognitive integration. The frequency of branding product exposure led to differences in the right occipital, right temporal, and parietal theta bands. However, the levels of significance were not as high as those associated with narrative structure. It is worth noting that the higher frontal delta and gamma power caused by video commercials with a single exposure may be indicators of attention for further investigation.Thirty subjects (15 men and 15 women) from Taipei, Taiwan, with an average age of 23.8 years and at least a bachelor’s level education were enrolled in this study. The subjects had a visual acuity of at least 0.8 after vision correction, and had no medical history of color blindness, visual impairment, or any relevant neurological and psychological disorder. The subjects were not addicted to drugs or alcohol and stopped taking stimulants that are able to affect brain activity  48 hours before the experiment. In accordance with the Declaration of Helsinki6162To incorporate the amendments suggested by the pilot experiment, such as the avoidance of the influence of the subjects’ language comprehension of the story, all of our 30 subjects were from the Taipei metropolitan area, had at least a bachelor’s degree and some professional abilities, and achieved an intermediate proficiency on the National General English Proficiency TestIn addition, to ensure that the subjects’ judgments of the experimental stimuli were not affected by their cultural or artistic perception, the stimuli were chosen from the same artistic category and never previously broadcasted in TaiwanThe 32 video commercials were classified with narrative structure and branding product exposure as the independent variables in the experiment . A classThis study was performed in the Design Perceptual Awareness Lab (D:PAL) at the National Taiwan University of Science and Technology (Taiwan Tech). During the experiment, external noise, temperature, light, and any other possible disturbances were strictly controlled. The subjects were alone in the experimental room while they watched the videos and answered the questions. During this time, the experimenter was outside the room and observed the state of the subject and the EEG recording. The EEG recording and analysis systems Scan4.3.3 and STIM2 from Neuroscan were used. We used an electrode cap (Quik-cap) and a SynAmps2 amplifier. The 64-channel EEG signal was recorded according to the international 10–10 electrode placement system.The screen for watching the video commercials was placed on a table with a height of 74 cm. The center of the screen was at a 10–20° viewing angle and was 60–70 cm away from the subject. The instructions were provided before the experiment in order to allow the subjects to relax while they watched the videos and answered questions using a keyboard. Before the start of the video commercials, a cross symbol (+) appeared in the center of the screen for 1,000 milliseconds. Three questions were asked after each video clip: “Do you know what the advertised product is?”, “Do you like this product?”, and “Do you like this commercial?”. Questions two and three were accompanied by four answers representative of the subjects’ preference levels: “high”, “medium”, “low”, and “no feelings”. If the subject was not able to identify the product, the question regarding product preference was skipped. Thirty-two video commercials were played randomly with no repeats and with a break after every eight video commercials. The subject decided on the length of the break before continuing the experiment.In the analysis of the behavioral data, the scores for each item were summed up and one-way analysis of variance (ANOVA) was conducted to analyze the scores for branding product preference (“Do you like this product?”) and video commercial preference . The differences between the four groups of advertising stimuli were statistically analyzed. Pairwise comparisons of the data were performed using Scheffe post-hoc tests. Subsequently, the four groups of video commercials were combined into two groups using two independent variables: narrative structure and branding product exposure. Independent sample t-tests were performed to understand the influences of the two independent variables on the preference for the branding product and the video commercials.In the process of EEG analysis, a wide range of noises was examined to reduce their impact. This was followed by use of a high-pass filter with a cut-off frequency of 1 Hz and a transition band of 0.2 Hz to remove baseline-drifting artifacts. Subsequently, a low-pass filter with a cut-off frequency of 50 Hz and a transition band of 7 Hz was adopted to remove muscle artifacts and line noise. The sampling rate of the filtered EEG signals was down-sampled to 250 Hz to reduce data storage and analysis time.In order to control for the noise generated during the experiment and to explore the activations of various brain regions during the video commercials, independent component analysis (ICA) was carried out666669707172To understand common regional brain activation patterns in the 30 subjects, the K-means method5877Finally, four groups of stimuli were used as variables and fast Fourier transform (FFT)How to cite this article: Wang, R. W. Y. et al. EEG Spectral Dynamics of Video Commercials: Impact of the Narrative on the Branding Product Preference. Sci. Rep. 6, 36487; doi: 10.1038/srep36487 (2016).Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.


Polaritons in layered materials—including van der Waals materials—exhibit hyperbolic dispersion and strong field confinement, which makes them highly attractive for applications including optical nanofocusing, sensing and control of spontaneous emission. Here we report a near-field study of polaritonic Fabry–Perot resonances in linear antennas made of a hyperbolic material. Specifically, we study hyperbolic phonon–polaritons in rectangular waveguide antennas made of hexagonal boron nitride . Infrared nanospectroscopy and nanoimaging experiments reveal sharp resonances with large quality factors around 100, exhibiting atypical modal near-field patterns that have no analogue in conventional linear antennas. By performing a detailed mode analysis, we can assign the antenna resonances to a single waveguide mode originating from the hybridization of hyperbolic surface phonon–polaritons (Dyakonov polaritons) that propagate along the edges of the h-BN waveguide. Our work establishes the basis for the understanding and design of linear waveguides, resonators, sensors and metasurface elements based on hyperbolic materials and metamaterials. Here, the authors report a near-field study of hyperbolic phonon polaritons in linear antennas made of hexagonal boron nitride. Infrared nanospectroscopy and nanoimaging experiments reveal sharp Fabry-Perot resonances with large quality factors, exhibiting atypical modal behaviour. Polaritons—quasiparticles resulting from the coupling of photons and oscillating charges679109121315q(ω) =  presents a hyperboloid. For h-BN, we find two reststrahlen bands, where one of the permittivity components is negative. In the lower reststrahlen band (760–825 cm−1), the real part of the out-of-plane permittivity Re −1), the real part of the in-plane permittivity ReThe emergence of van der Waals materials opens novel opportunities for polariton-based photonic technologies17182021and 760–8 cm−1, thHere we study experimentally and theoretically linear antennas  made of the van der Waals material h-BN. We perform infrared nanospectroscopy and nanoimaging of the antennas in the upper reststrahlen band, yielding the antennas' local spectral near-field response and modal near-field distribution, respectively. We find resonances of high-quality factors of about 100 and puzzling near-field patterns. By full-wave simulations we perform a comprehensive analysis of both the experimental images and near-field spectra. We show that the resonances and exotic near-field patterns are governed, interestingly, by hyperbolic surface phonon–polaritons  in the h-BN antennas. The HPs are reflected at the ends of the antennas, giving rise to Fabry–Perot resonances. The strongly enhanced near fields caused by these resonances are imaged and spectrally analysed by recording the field scattered by the tip, Es.For infrared nanoimaging we used a scattering-type scanning near-field optical microscope s-SNOM333435. I3334Es, was recorded with an asymmetric Fourier transform spectrometer   and recorded the amplitude of the tip-scattered field with a pseudo-heterodyne Michelson interferometerroscopy) . By recon=1, …, 6 in ωn, indicating antenna resonances. From the width of the peaks, we estimate quality factors (Q) in the range of Qn ∼80–120 (see ‘Methods' section). They are comparable to that of h-BN nanoconesQ-factors reported for metal (plasmonic) antennas in the mid-infrared spectral rangeWe first perform nano-FTIR spectroscopy  of a repn, we find strong near-field signal oscillations along the antenna axis. The number of near-field signal maxima and minima is steadily growing with increasing frequency, while the distance between them  decreases. Such behaviour is a clear indication of a spectrally evolving standing wave pattern, that is, longitudinal Fabry–Perot resonances in the h-BN rod, similar to plasmon resonances in metal rods38n=1, …, 6 peaks in n=1) manifests at 1,370 cm−1 by the two near-field signal maxima close to the rod extremities, while the second-order (n=2) resonance  exhibits a strong near-field signal in the centre of the rod and two less pronounced near-field signal maxima at the rod extremities. The third-order (n=3) resonance at 1,411 cm−1 clearly shows the four typical near-field signal maxima along the antenna axis. The trend continues up to the sixth order. However, the peaks become less pronounced, which we attribute to the increase of losses for higher-order longitudinal antenna modes , we obtain near-field spectra, |Es/Es,Au|. By plotting the near-field spectra as a function of the lateral dipole position, we obtain spectral near-field line scans. The simulated point spectra at the rod extremity and centre are shown in We corroborated our experimental data with full-wave simulations of the near-field spectra. To that end, we used a model where the metallic tip is approximated by a dipole source located above the antenna (see ‘Methods' section). This model has been shown to reliably reproduce the experimental near-field images in graphene nanoresonatorsω(q) of the HP mode yielding the longitudinal Fabry–Perot resonances, we extracted from both the experimental  and to the atomic layers of the h-BN slab out of which the antennas were fabricated. In good approximation, they can be calculated by using the relation Ln is the distance between the adjacent maxima in the central part of the antenna (for each resonance order n>2). To be more precise, we determined the qn by fitting the line profiles with a sine function, as described in the q is significantly increased compared to that of free-space photons of the same energy, q0, and strongly increases with frequency. Both findings indicate that highly confined waveguide polaritons are the cause of the longitudinal Fabry–Perot resonances. To identify the waveguide mode, we performed a numerical analysis of the electromagnetic modes in an infinitely long h-BN waveguide, which has a cross-section that is similar to that of the antenna (see ‘Methods' section). As expected for hyperbolic material waveguidesEz)  up to wavevectors q≈120 q0. We find that ω(q) asymptotically approaches the frequency ωSO=1,576 cm−1 -th resonance order , at two different frequencies. Inside the h-BN waveguide, we recognize ‘zig-zag' patterns. They manifest HP rays that emerge from corners2146θ, of the hyperbolic rays depends on the frequency ω  exhibit an increasing number of near-field signal maxima along the antenna, revealing the different resonance orders. Importantly, the transverse near-field profile is identical for all antennas , confirming that the exotic transverse near-field profile of the SM0-S mode is a robust and intrinsic feature of the waveguide mode, and not affected by the antenna length.Finally, we performed near-field imaging of differently long antennas of the same width and height . With inQ-factors of about 100, which make the antennas interesting building blocks for the development of infrared molecular sensors, narrowband thermal emitters or metasurfaces for flat infrared photonic elements. By a detailed mode analysis, we demonstrated that the waveguide mode exhibiting longitudinal Fabry–Perot resonances originates from the hybridization of hyperbolic surface phonon–polaritons (Dyakonov polaritons) that propagate along the edges of the h-BN antennas . This mode exhibits a stronger field confinement  compared to the waveguides' volume modes (of the same order). We note that the odd longitudinal Fabry–Perot resonances can be excited by far-field illumination, which could enable, for example, field-enhanced far-field spectroscopy applications. From a general perspective, our results provide valuable insights into the fundamental properties of polariton modes in deep subwavelength-scale linear waveguides based on naturally or artificially layered materials, such as van der Waals materials and heterostructures or metal-dielectric metamaterials. The knowledge about the mode properties will be of critical importance for the development of photonic circuits based on hyperbolic plasmon–polariton and phonon–polaritons in linear waveguides and antennas.In conclusion, we employed real-space infrared nanoimaging and nanospectroscopy for studying Fabry–Perot resonances of hyperbolic phonon–polaritons in finite-length h-BN waveguides acting as infrared antennas. We found resonances exhibiting 2 (250 nm) substrate using the deterministic dry transfer technique49Large and homogeneous h-BN flakes were isolated on a Si/SiO2 250 nm) substrate. To that end, we first performed mechanical exfoliation of commercially available h-BN crystals  using blue Nitto tape . Then, we performed a second exfoliation of the h-BN flakes from the tape onto a transparent polydimethyl-siloxane stamp. After that, via both optical inspection and atomic force microscope (AFM) characterization of h-BN flakes on the stamp, high-quality flakes with large areas and required thickness were identified and transferred onto a Si/SiO nm subst2 gun.The h-BN nanoantennas were fabricated from the h-BN flakes via high-resolution electron beam lithography using a double-layer poly(methyl methacrylate) (PMMA) resist (495 A4/950 A2), e-beam evaporation of Cr (3 nm) and thermal evaporation of Al (40 nm) onto the developed resist, lift-off in acetone, and chemical etching of the h-BN flake with a SF6/Ar 1:1 plasma mixture at 20 sccm flow, 100 mTorr pressure and 100 W power for 30 s (RIE OXFORD PLASMALAB 80 PLUS reactive ion etcher). Finally, the metal mask was removed by immersing the sample in chromium etchant  for 20 min, rinsed in deionized water and dried using a N−1, Daylight Solutions, USA), focused with a parabolic mirror (NA=0.4), at an angle of 60° relative to the surface normal. The p-component of the tip-scattered light ES, collected with the same parabolic mirror, was recorded with a pseudo-heterodyne Michelson interferometer  is based on an AFM. The vertically oscillating conventional metal-coated (Pt/Ir) tip  acts as near-field probe. The tapping frequency and amplitude was Ω≈270 KHz and about 100 nm, respectively. Tip and sample were illuminated with the p-polarized mid-infrared laser beam of a QCL , which is generated by difference frequency generation using a Femtofiber pro IR and a SCIR laser from Toptica (Germany). Fourier transform spectroscopy is accomplished as follows. The tip-scattered signal is analysed with an asymmetric Fourier transform spectrometer . We normalized the obtained point spectra to a reference spectrum Es,Au, recorded on gold. A complex-valued division For nano-FTIR spectroscopy, the same basic s-SNOM set-up (AFM+parabolic mirror) described above is used. Tip and sample are illuminated with a broadband mid-infrared laser supercontinuum , which computationally are much less demanding and much less time consuming. Second, analysing the modes in an infinite waveguide provides a simple and intuitive physical interpretation of the resonances in our antennas. Our approach is justified by the excellent agreement between the calculated and experimental dispersion , as wellWe further assumed a rectangular cross-section for the h-BN waveguide and thus neglected the slight tilting of the fabricated antenna edges, which are seen in the The calculations of the line profiles shown in In the simulations shown in The perpendicular and parallel components of the permittivity tensor, a=|| or ωLO and ωTO refers to the transversal (TO) and longitudinal (LO) phonon frequencies, γ denotes the damping constant and Where The data that support the findings of this study are available from the corresponding author on reasonable request.How to cite this article: Alfaro-Mozaz, F. J. et al. Nanoimaging of resonating hyperbolic polaritons in linear boron nitride antennas. Nat. Commun.8, 15624 doi: 10.1038/ncomms15624 (2017).Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Supplementary Figures


The transmission of information from an experienced demonstrator to a naïve observer often depends on characteristics of the demonstrator, such as familiarity, success or dominance status. Whether or not the demonstrator pays attention to and/or interacts with the observer may also affect social information acquisition or use by the observer. Here we used a video-demonstrator paradigm first to test whether video demonstrators have the same effect as using live demonstrators in zebra finches, and second, to test the importance of visual and vocal interactions between the demonstrator and observer on social information use by the observer. We found that female zebra finches copied novel food choices of male demonstrators they saw via live-streaming video while they did not consistently copy from the demonstrators when they were seen in playbacks of the same videos. Although naive observers copied in the absence of vocalizations by the demonstrator, as they copied from playback of videos with the sound off, females did not copy where there was a mis-match between the visual information provided by the video and vocal information from a live male that was out of sight. Taken together these results suggest that video demonstration is a useful methodology for testing social information transfer, at least in a foraging context, but more importantly, that social information use varies according to the vocal interactions, or lack thereof, between the observer and the demonstrator. The trade-off to using this paradigm is that even after extensive training the performance of the demonstrator and thus the social information provided to the observer can vary substantially from trial-to-trial. The housing and training of the demonstrator individuals can also be time consuming. Video playback may provide a way to standardize the demonstration and to reduce the total number of animals needed, as well as providing repeatability and stimulus control  and budgerigars (Melopsittacus undulates) yawn more in response to videos of conspecifics yawning than to control videos in which conspecifics were engaged in other behaviours (Taeniopygia guttata) and Bengalese finches (Lonchura striata) sing directed song to video presentations of female conspecifics (Octopus tetricus) readily approached and touched the video screen when presented with a crab video, and reduced their activity, a natural response for this solitary species, in response to a video of a conspecific  potentiate alarm calls produced in the presence of a predator model (Amphibolurus muricatus) produce aggressive displays in response to videos of conspecific males  copy foraging choices of live and video demonstrators (Coturnix japonica) and tool manufacture and use in chimpanzees sound was not necessary for social learning to occur  and kept on a 14:10 light:dark cycle with temperature at ∼20 °C and humidity at ∼50%. Birds were given free access to mixed seeds, water (vitamin-supplemented 3 days per week), cuttle bone, oystershell, and vitamin block and fresh spinach (3 × per week). Each cage had several perch sizes and types and floors were covered with pressed wood pellets. At the end of the experiment birds were returned to the group housing cages described above. Birds were visually assessed for health at least two times per day by the researcher (LMG) and one additional time per day by the animal care staff. All birds were between one and three years of age at time of testing. The work described here was conducted with the approval of the University of St Andrews Animal Welfare and Ethics Committee.2.2®), which connected to each of the four video screen via a separate HDMI cable.The experiments were carried out in a test room that contained a demonstrator cage and four observer cages. White opaque curtains between each cage allowed subjects to hear and vocally interact but not see each other for the duration of the experiments. Each observer cage . For group two there were five demonstrators. Four demonstrators participated in one trial each and one demonstrator participated in two trials .The subjects were 43 adult zebra finches  that were bred at the University of St Andrews. Four observers were tested in each trial (4 observers per demonstrator) and there were two experimental groups: 2.3.2Each trial lasted approximately 24 h. The observer viewed the behaviour of the demonstrator in the same room, visually occluded from the observer with white opaque curtains, via a video screen. The images that the observer viewed on the video screen were streamed live via the GoPro (30fps 1080p). While the demonstrator could not see the observers he could vocally interact with them.On Day 1, one bird was placed in each of the observer and the one demonstrator cage. At this time, all opaque curtains between all birds, and between the observer and the video screen were in place so the birds could not see one another or the video screen. The only food available to the demonstrator bird was provided in one of two experimental feeders (pink or purple). Thus the demonstrator bird learned which feeder to ‘demonstrate’ during the observation phase (described below) the next day. On Day 2, food was removed from all cages (4 observers and 1 demonstrator) two hours post light onset.There were two phases in each trial, the observation phase followed by a test phase. The observation phase began after the two-hour food deprivation period. During the observation phase, the feeder that had been removed from the demonstrator’s cage during the food deprivation period was returned. Now the demonstrator had two feeders, one pink, one purple, only one of which contained seeds. The 30-min observation phase started when the opaque curtain between the observer cages and the video screen was removed so that the observer could view the demonstrator’s behaviour on the video screen.During the test phase, which began immediately after the 30-min observation phase, the opaque barrier between the observer and the video screen was returned and one pink and one purple feeder, each containing seeds, was attached to the observer cage. With the exception of the demonstration that was just viewed, these coloured feeders were novel to the observers. The spatial location of the pink and purple feeders on the observers’ cage mirrored that of the video image of the demonstrator. In this way, both colour and spatial cues indicate the demonstrator’s feeder choice. This test phase lasted 60 min. The behaviour of the observers was video recorded. At the end of the test phase, the observers were returned to their stock cages, and new birds were placed in the observer cages for testing on the following day.2.42.4.1The subjects in this Experiment were 16 adult female zebra finches, seven were bred at the University of St Andrews and nine were from a local breeder.2.4.2group one from Experiment 1 were used as playbacks for the remainder of Experiments (2–4). In Experiment 2 these videos were played on the same video screens with full audio (measured at 60 dB at head height of the zebra finch when perched on the perches closest to the video monitor.). There were four videos total: each male served as a demonstrator on two trials , demonstrating a different colour each trial.Thirty-minute video recordings of the demonstrators for 2.4.3The procedure for this experiment was similar to the Experiment 1 with the following exceptions. Here, the video on the screen was a playback and was not live streamed. Thus, these observers saw and heard the demonstrators (same as those in Experiment 1) but they could not vocally interact with him because the video was pre-recorded.2.52.5.1The subjects were 16 adult female zebra finches, nine were bred at the University of St Andrews and seven were from a local breeder.2.5.2The procedure for this experiment was similar to that of Experiment 2 except that the demonstrator videos were played without sound.2.62.6.1n = 20 observers total).The subjects were 23 adult zebra finches  bred at the University of St Andrews. Two decoy males were used for two trials each and a third decoy male was used for one trial . To quantify feeder colour preference the following measures were calculated: (1) proportion of pecks to the feeder containing seeds for the demonstrator bird and, (2) the proportion of pecks by the observer bird to the demonstrator’s feeder colour.2.8group one, each participated in two trials . Demonstrator A pecked the baited feeder 944 times when that feeder was purple and 1388 times when that feeder was pink. Demonstrator B pecked the baited feeder 892 times when that feeder was purple and 753 times when that feeder was pink. No pecks were ever delivered to the non-baited feeder. Videos of these four trials were used during the observation phase for Experiments 2–4. Thus, the female observers across all of these Experiments saw the same visual demonstration.There were two male demonstrators for group two. Demonstrator A was used in two trials: he did not feed during the observation on one trial and thus the four observers for this trial were not used. In his second trial, Demonstrator A pecked at the baited feeder (pink) 522 times. Demonstrator B did not feed during the observation phase and thus the four observers for this trial were not used. Demonstrator C pecked at the baited feeder (purple) 180 times. Demonstrator D pecked at the baited feeder (pink) 121 times. Demonstrator E pecked at the baited feeder (purple) 114 times.There were five male demonstrators for 2.9group two in the Experiment 1  we used one-tailed tests because we had a priori expectations that if video demonstration worked in our experimental contexts, there should have been an effect in the same direction as for live demonstrators . Each observer birds could therefore be classified as having (1) copied the colour choice of the demonstrator bird, (2) avoided the colour choice of the demonstrated bird, or (3) having no preference. A Pearson Chi-square test was used to compare the proportion of females who copied across the four experiments. To test for systematic copying in the Experiments, we carried out one-sample Wilcoxon signed-rank tests on the proportion of pecks by the observer bird to the colour of feeder used by the demonstrator. For all but strators . For grostrators . All the33.1Z = 0.1, P = 0.4 and Experiment 4, Z = 0.78, P = 0.29) preferred one colour feeder over the other. Forty-nine (of 72) birds’ preference scores differed significantly from 0.5 . The binomial test could not be performed on the remaining 23 birds because these individuals exclusively ate from one feeder colour (i.e. preference = 1.0) so the performance of these individuals was considered to be different from that of chance. Overall, birds chose the feeder of the same colour as that used by the demonstrator .Ten observers did not eat during the test phase leaving the final group totals: Experiment 1 males, n = 15, females, n = 15; Experiment 2, n = 15; Experiment 3, n = 15; Experiment 4, n = 14. The number of pecks by all observers ranged from 9 to 1005. All but two birds , N = 72) = 8.0, P = 0.09. The females that observed the live streaming video demonstrator (Experiment 1) were much more likely to direct their pecks to the feeder of the demonstrated colour than expected by chance , we found that preferences for the demonstrated colour did not differ across the five groups  did not direct more of their pecks to the feeder of the demonstrated colour than expected by chance , the females were more likely to direct their pecks to the feeder of the demonstrated colour than to the feeder of the other colour  did not direct more of their pecks to the feeder of the demonstrated colour than to the feeder of the other colour  males did not systematically copy either sex . It seems plausible that the females failed to copy because as they swapped vocalizations with the live male, they did not pay attention to the video. This supposition is supported by female zebra finches preferring their own mate over an unknown male when vocal and visual cues match but she does not prefer her own mate when his vocalizations are replaced by those of unknown individual . AlthougIt is unclear whether the females that were ignored by the male demonstrator (1) did not acquire the social information or (2) did not use the social information. This distinction was discernible in inexperienced male zebra finches watching experienced males build a nest. In that experiment, only those males that saw a familiar male building copied the demonstrator’s material choice, whereas the males that saw an unfamiliar male building did not copy the choices of their demonstrator . And yetEven in this social species, then, the circumstances under which the animals use the information they acquire from conspecifics is much more varied than one might have expected and may be due, in part, to individual differences in sampling behaviour . This wo


Saccharomyces cerevisiae has been successfully used for uncovering molecular mechanisms through which impaired lipid metabolism causes lipotoxicity and elicits different forms of regulated cell death. Here, we discuss mechanisms of the “liponecrotic” mode of regulated cell death in S. cerevisiae. This mode of regulated cell death can be initiated in response to a brief treatment of yeast with exogenous palmitoleic acid. Such treatment prompts the incorporation of exogenously added palmitoleic acid into phospholipids and neutral lipids. This orchestrates a global remodeling of lipid metabolism and transfer in the endoplasmic reticulum, mitochondria, lipid droplets, and the plasma membrane. Certain features of such remodeling play essential roles either in committing yeast to liponecrosis or in executing this mode of regulated cell death. We also outline four processes through which yeast cells actively resist liponecrosis by adapting to the cellular stress imposed by palmitoleic acid and maintaining viability. These prosurvival cellular processes are confined in the endoplasmic reticulum, lipid droplets, peroxisomes, autophagosomes, vacuoles, and the cytosol.A disturbed homeostasis of cellular lipids and the resulting lipotoxicity are considered to be key contributors to many human pathologies, including obesity, metabolic syndrome, type 2 diabetes, cardiovascular diseases, and cancer. The yeast  Some forms of cell death are classified as “programmed” cell death subroutines; they involve molecular machineries dedicated to commit cellular “suicide” that is aimed at providing certain benefits for development and/or survival of the entire organism –6. OtherS. cerevisiae is a model organism most commonly and productively used for studying different forms of RCD elicited by perturbations in lipid metabolism , 5934, 5SB1 gene –87. A prSB1 gene , 88–91. The bulk quantities of POA-containing phospholipids initially synthesized in the ER of yeast cells that are committed to liponecrotic RCD accumulate not only in the PM but also in both membranes enclosing mitochondria  34, 59], 5934, 5The buildup of POA-containing phospholipids in the IMM and OMM of yeast committed to liponecrotic RCD not only impairs mitochondrial functionality but also considerably increases the intracellular concentration of reactive oxygen species (ROS) that are produced in mitochondria as by-products of respiration  34, 59], 5934, 5If the stress imposed by an exposure to POA does not exceed a toxic threshold, yeast cells can use at least four different processes to cope with this stress and maintain viability .One of these prosurvival cellular processes is an assimilation of POA into neutral lipids (TAGs and EEs), which occurs in the ER and is followed by a buildup of POA-containing neutral lipids in LDs  34, 58,,58, 59. β-oxidation of POA in peroxisomes of yeast exposed to this monounsaturated free fatty acid  the buildup of POA-containing phospholipids in the PM and the ensuing increase in the permeability of the PM to small molecules and (2) the accumulation of POA-containing phospholipids in both mitochondrial membranes and the resulting decline in mitochondrial functionality, which is needed to support the prosurvival process of incorporating exogenous POA into neutral lipids . Two othOur hypothesis further suggests that prosurvival processes are likely to be nodes of the same branched subnetwork integrating the four pro-death processes. Two direct prosurvival processes relieve the extreme cellular stress by preventing the buildup of POA-containing phospholipids in the PM and mitochondria; they include the following: (1) the assimilation of POA into neutral lipids in the ER and the subsequent buildup of POA-containing neutral lipids in LDs and (2) peroxisomal oxidation of POA . Two indIn sum, the above hypothesis posits the following: (1) the balance between different pro-death and prosurvival processes may be regulated by their relative rates and (2) these relative rates may be defined by the extracellular and/or intracellular concentrations of POA, nutrient availability, the metabolic state of a yeast cell, and the chronological age of a yeast cell.Yeast cells undergoing POA-induced liponecrotic RCD exhibit characteristic morphological and biochemical traits , 58, 59.While yeast cells committed to POA-induced liponecrotic RCD do not display such characteristic traits of apoptotic RCD as nuclear fragmentation and PS externalization within the PM bilayer, the metacaspase Yca1 and serine protease Nma111 play essential roles in both liponecrotic and caspase-dependent apoptotic modes of RCD , 59. HowWhile yeast cells undergoing POA-induced liponecrotic RCD do not display such hallmark trait of autophagic RCD as extreme cytoplasmic vacuolization instigated by a buildup of double-membrane vesicles called autophagosomes , 58, 59,While yeast cells undergoing POA-induced liponecrotic RCD do not exhibit such hallmark feature of necrotic RCD as a severe fracture of the PM , 58, 59,A trait which is unique to POA-induced liponecrotic RCD is a buildup of POA-containing neutral lipids in numerous LDs, a feature that has not been reported for apoptotic, autophagic, or necrotic subroutine of RCD  1, 58, –113, 115Because POA-induced liponecrotic RCD has several different traits in common with apoptotic, autophagic, and necrotic modes of RCD, we hypothesize that the molecular subnetwork of POA-induced liponecrotic RCD is integrated into a signaling network that orchestrates different RCD scenarios in yeast cells. Other pathways and subnetworks integrated into this signaling network may include apoptotic, autophagic, and necrotic pathways and subnetworks of RCD. In our hypothesis, the molecular subnetwork of POA-induced liponecrotic RCD only partially overlaps with apoptotic, autophagic, and necrotic RCD pathways and subnetworks of the network. Our hypothesis satisfactorily explains the observed existence of several proteins that are common to liponecrotic, apoptotic, autophagic, and necrotic modes of RCD , 58, 59.Our hypothesis on the existence of an RCD signaling network orchestrating different RCD scenarios in yeast cells is reminiscent of the hypothesis on the global programmed cell death (PCD) network that has been proposed and then confirmed for mammalian cells –120. A sPOA-induced liponecrotic RCD is an age-related mode of RCD, as the susceptibility of a population of yeast cells to POA-induced liponecrosis increases with the chronological age of this population , 59, 121Our recent unpublished findings indicate that in yeast cultured under non-CR conditions on 1% or 2% glucose, the risk of age-related death depends not only on the POA-induced liponecrotic mode of RCD but also on ROS-induced apoptotic RCD mode. Moreover, we found that the liponecrotic and apoptotic modes of RCD have different relative contributions to age-related death of non-CR yeast at different periods of chronological lifespan (CLS). The apoptotic mode of RCD predominates during diauxic (D) phase, apoptotic and liponecrotic RCD modes equally increase the risk of death during post-diauxic (PD) phase, whereas the liponecrotic mode of RCD prevails during stationary (ST) phase of culturing under non-CR conditions (our unpublished data). The longevity-defining mode of liponecrotic RCD is elicited by the accumulation of POA and other free fatty acids in chronologically aging non-CR yeast cells that progress through PD and ST phases of culturing (our unpublished data). In contrast, the longevity-defining mode of apoptotic RCD is caused by the rapid decline of mitochondrial functionality and rise of mitochondrially generated ROS in chronologically aging non-CR yeast cells progressing through D and PD phases of culturing (our unpublished data). CR diet, which is implemented by culturing yeast on 0.2% or 0.5% glucose, decreases the risk of age-related death by attenuating liponecrotic and apoptotic RCD modes during D, PD, and ST phases; these effects of CR are due to its abilities to (1) decrease free fatty acid (including POA) concentrations during PD and ST phases of culturing and to (2) improve mitochondrial functionality and to lessen concentrations of mitochondrially generated ROS during D and PD phases of culturing (our unpublished data).LCA is a geroprotective chemical compound that delays yeast chronological aging mainly under CR conditions . LCA exhOf note, LCA decreases yeast susceptibility to the mitochondria-controlled, ROS-induced mode of apoptotic RCD if added to growth medium at the time of cell inoculation and during L, D, PD, or ST phase of culturing . In yeasCaenorhabditis elegans, which define lifespan earlier or later in life (resp.) [In sum, it is conceivable that liponecrotic and apoptotic modes of RCD may have different effects on yeast CLS at different periods of life. This is similar to the “P” (“big P”) and “p”  modes of death in the nematode  (resp.) . The P m (resp.) .Several exogenously added lipids –16, as wAltogether, these findings further support our hypothesis (which is outlined in S. cerevisiae cells use several different mechanisms to mount a protective stress response and maintain viability. This complex stress response consists in remodeling of at least four cellular processes. If the POA-induced lipotoxic stress exceeds a threshold, yeast cells commit suicide that is assisted by a complex molecular machinery. This molecular machinery alters the spatiotemporal dynamics of several cellular processes to execute a liponecrotic subroutine of RCD. The liponecrotic mode of POA-induced RCD plays an essential role in defining longevity of chronologically aging yeast, likely in coordination with an apoptotic mode of RCD. The molecular subnetwork of POA-induced liponecrotic RCD may be integrated into a global signaling network of partially overlapping molecular pathways and subnetworks, each executing a different mode of lipotoxic or nonlipotoxic RCD.To cope with the lipotoxic stress imposed by an exposure to POA,