Age was the most significant predictor of hearing levels across listening and health-related fitness variables. PLD user status did not impact hearing measures, yet PLD users who listened less than 8 hours per week with intensities of less than 80 dBA were found to have better hearing. Other variables found to be associated with hearing levels included: years listening to PLD, number of noise environments and use of ear protection. Finally, a healthy waist-to-hip ratio was a significant predictor of better hearing, while body mass index approached, but did not reach statistical significance. This study examined the relationship between hearing levels, otoacoustic emission levels and listening habits related to the use of personal listening devices (PLDs) in adults with varying health-related fitness. Duration of PLD use was estimated and volume level was directly measured. Biomarkers of health-related fitness were co-factored into the analyses. 115 subjects ages 18–84 participated in this study. Subjects were divided into two sub-groups; PLD users and non-PLD users. Both groups completed audiological and health-related fitness tests. Due to the mismatch in the mean age of the PLD user  Hearing loss is the third most prevalent chronic health condition within the adult population in the United States . In the NIHL is a preventable sensorineural hearing loss that begins with a high-frequency deficit and occurs gradually as the result of chronic noise exposure . The incThe impact of PLD use on hearing must be examined in the context of the intensity of sound as well as the duration of listening. While individual susceptibility exists, higher intensities and longer durations of noise exposure damage ears more than lower intensities and shorter durations . Given tAlthough the majority of PLD users listen within the safe listening range, 15–25% of PLD users exceed safe listening levels . While pMoreover, NIHL is not the only cause of hearing loss. There are several uncontrollable factors leading to hearing loss, including genetics, age, gender, and race ,14. Many2 max), has been shown to protect hearing, possibly due to increased internal auditory artery and cochlear blood flow [Despite the fact that the prevalence of hearing loss is increasing, preventative measures such as noise exposure reduction, use of ear protection and increased health and fitness may have a positive impact on preserving hearing acuity, particularly with age . In adulood flow . This inood flow . The ben2 max levels, have the best hearing sensitivity [et al. found that following an 8-month cardiovascular fitness training program, subjects suffered less (TTS) and recovered hearing faster than an untrained control group [Research by Hutchinson and Alessio has consistently demonstrated that individuals with high cardiovascular fitness, measured by VOsitivity . It is hsitivity . What’s sitivity . Cardiovsitivity . A studyol group . Furtherol group . The objectives of the current study were to (1) determine if PLD users have worse hearing than non-PLD users (2) to determine if PLD users who listen to music louder than 80 dBA free field equivalent levels have worse hearing than PLD users who listen to music at levels less than 80 dBA (3) to determine what additional factors such as audiological history, hearing protection use, exposure to noise and amount of time listening to PLDs influence hearing acuity and (4) to examine which health-related fitness variables have a positive influence on hearing acuity. A total of 115 subjects, ages 18–84, were recruited from the Oxford, Ohio area via flyers posted at locations throughout Oxford. Participants were scheduled to complete the kinesiology and audiometric portions of the study via email. Interested participants received an email detailing expectations for each part of the study. Upon arrival to the first test session participants completed an informed consent form approved by the Miami University Institutional Review Board. Participants were categorized into two groups, earbud PLD users and non-PLD users. PLD users were instructed to bring their most frequently used PLD and headphones with them to testing. Both PLD users and PLD non-users began by completing a hearing health questionnaire investigating hearing health as well as past and present noise exposure. After completing the questionnaire, participants underwent otoscopy to examine health of the outer ear and tympanic membrane. Participants with visible cerumen occlusions or external ear abnormalities were excluded from the study. Participants were then screened for middle ear disease using tympanometry. Those with peak pressure within +50 to –200 daPa and compliance greater than 0.3 mL were included. All audiometric testing and Otoacoustic Emission (OAE) testing occurred in double-walled sound-attenuating booths. After confirming the physical health of the ear, the Hughson-Westlake method was used to obtain pure tone thresholds on a Grason-Stadler 61 diagnostic audiometer  at frequencies of 0.25 kHz, 0.5 kHz, 1 kHz, 2 kHz, 3 kHz, 4 kHz, 6 kHz and 8 kHz. Pulsed pure tones were delivered through Etymotic Research-5A insert earphones . All audiometers and acoustic instruments met current American National Standards Institute (ANSI) standards . 1/f2 ratio of 1.22 from 2 kHz to 8 kHz at a 10 dB level difference between the primary tones (L1 > L2). The present study evoked the DPOAE at two intensity levels to investigate the amplitude differences at 45/55 dB SPL (moderate level) and 55/65 dB SPL (high level). Research has shown that OAE testing may be a possible predictor of future NIHL and OAEs may decrease in amplitude prior to changes in audiometric thresholds [Distortion Product Otoacoustic Emission (DPOAE) (2f1-f2) amplitudes were measured using the Biologic Systems Scout OAE software version 3.45 system with two intensity levels from 2 kHz to 8 kHz. Testing was completed at a fresholds ,22. Due et al. [Actual measurements of each participant’s PLD intensity levels were assessed with Audioscan Verifit VF-1 equipment  and a probe microphone inserted into the ear. Calibration of the instrument occurred Monday of each week. A reference microphone was placed over the participant’s ear with a probe microphone tube inserted into the ear canal. The probe tubing was inserted at 28 mm for females and 30 mm for males  using otet al. . et al. and were used to examine participants’ self-reported listening patterns as well as knowledge and education regarding noise exposure and hearing [Upon completion of audiological testing and Verifit probe tube measurements, the PLD user participants were asked to complete a listening habits survey that asked for information about use of personal listening devices. After measurements were finished, participants completed a second questionnaire querying their knowledge of potential risks of hearing loss. These questionnaires were adapted from Worthington  hearing . These q2 test. All instrumentation was calibrated daily and tests performed by a trained technician. Blood pressure and heart rate were measured on the left arm of all subjects after they had been sitting for ten minutes using an Omron Intellisense Digital Blood Pressure Monitor, Model HEM-907xL . Two readings were recorded, and averaged. If more than a 5% difference occurred between readings, the protocol called for a third reading to be taken after ten minutes. Blood lipid readings were collected using a Cholestech LDX analyzer, catalog number 02111239 . Participants were instructed to fast for 12-hours prior to the blood lipid tests. Specific markers measured were total cholesterol (TC), high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides, non-HDL, TC/HDL and glucose.Specific markers of health related fitness included resting blood pressure and heart rate, blood lipids, body mass index (BMI), waist-to-hip ratio (W:H), hand grip strength, daily activity assessments via pedometer, and cardiovascular fitness using a sub-maximal VOBody composition was measured using a Tanida bioelectrical impedence body composition analyzer, Model TBF-300A . Participants were instructed to remove their shoes and socks and step on the electrode plates on the scale portion. For all participants, weight of clothes was entered as 1.0 lb. and body type entered was “Athletic” for their gender. A SECA 210 cm stadiometer  was used to measure height. Specific markers recorded from the Tanida scale were weight, body fat percentage (FAT %), fat mass (FM) and fat free mass (FFM). Hip and waist measurements were taken using a Gulick II Tape, model 67020 . Measures were taken around the umbilicus and widest area around the buttock. Handgrip strength was measured using a Takei physical fitness test grip strength dynamometer, model number 68812 . Participants were instructed to stand, hold the dynamometer at their side and to squeeze as hard as they could for approximately 2 sec. Right hand and left hand were measured twice and the better score was taken. Daily activity estimates were made by means of pedometer step data using the Yamax pedometer model SW-200 . Participants were instructed to reset the pedometer each morning, wear the pedometer for all activities and record their daily steps at night for 14 days. The collection of pedometer steps was used to gain objective data for daily activity and also to validate self-reported exercise and daily activity routines.2 max based on the well-known relation between heart rate and VO2 max. All subjects successfully completed the single-stage submaximum test and a reliability measure between VO2 max values predicted from this submaximal test and a true maximal test in a subsample (n = 20) was very strong (r = 0.86) [Cardiovascular fitness was assessed by submaximal exercise tests whereby participants achieved a steady heart rate while walking for 3 min on a flat treadmill at a personally selected walking speed and 4 min at a five-degree incline. During this time, heart rate was measured with a Polar chest strap  and a wristwatch. Minimum speed was no less than 4.3 mph and maximum speeds for men and women were 7.5 and 6.5 mph, respectively. According to the protocol, steady state heart rates were not to exceed 180 bpm for either gender. The protocol was modified slightly by having the participants ‘warm-up’ by walking at 3 mph for the first minute. Heart rate was measured with a Polar chest strap (T31) and wristwatch. At the completion of the test, the subject’s body weight in kilograms (BW), speed (mph), HR at termination (bpm) and gender  were used to calculate an estimated VO = 0.86) . ReliabiDescriptive statistics were performed on the data set using SAS Software Version 9.2 for Windows . The data were first summarized and examined for outliers and consistency. Several preparatory steps were taken to ready the data for analysis. Usage times were calculated by multiplying self-reported hours per day by days per week of PLD usage. Two samples of Verifit SPL values converted to A-weighted free field equivalents were each averaged for comparison to noise exposure standards and to pure tone threshold data. Pure tone thresholds in HL were analyzed in two ways as dependent variables: traditional frequency range (0.25–8 kHz) and high-frequency (HF) range (4–8 kHz).n = 75) and non-PLD users (n = 40). The mean age of PLD non-users (52.78 years) was 12 years higher than the mean age of PLD users (40.71 years). For participants under age 50, the traditional frequency range mean was 10.97 dB HL, while the HF mean was 13.76 dB HL. Mean hearing thresholds between 0.25 and 8 kHz were poorer for participants over age 50, who had a mean of 14.58 dB HL and a HF-band mean of 22.81dB HL , the HF-band range (4–8 kHz) or DPOAEs. When examining the traditional frequency-band means, age was found to be statistically correlated (p < 0.001), while PLD listening status was insignificant (p = 0.7403). In the HF-band means, age was again the only significant variable contributing to hearing levels (p < 0.001), while PLD status was insignificant (p = 0.4787). A similar trend was observed when comparing the DPOAEs of PLD users and non-PLD users at both low and high intensity levels from 2 to 8 kHz. Age was a significant indicator of DPOAE levels at the low (p < 0.0001) and high (p < 0.0001) intensity levels, while PLD user status was deemed insignificant (p = 0.9479). Due to the mean age mismatch of the PLD user group p < 0.0001) and listening level in silence (p = 0.0288) were the only two variables found statistically related to traditional frequency means. For the HF-band means, only age (p < 0.0001) was found to be significant. The listening levels of the PLD user group were then examined in relation to hearing acuity. A total of 49 PLD users were included in this analysis. 36% of PLD users were excluded for failing for failing to complete all portions of audiologic testing. Of these 49 users, 94% were considered to have normal traditional frequency-band means (pure tone levels < 25 dB HL), while 6% were found to have abnormal levels (pure tone levels > 25 dB HL). In the HF range (4 kHz–8 kHz), 86% were found to have HF means in the normal range, while 14% of participants HF means were considered abnormal. Age (p = 0.0002) and high (p = 0.0007) intensity levels. Listening at harmful levels in silence had no significance on DPOAEs at the moderate 2–8 kHz (p = 0.2051) or loud 2–8 kHz (p = 0.0912) intensity levels. The second measurement in the presence of 75 dB SPL background noise revealed that age was again the only significant influence on the traditional frequency range means (p < 0.0001) as well as HF-band means (p < 0.0001). Participants who listened at levels above 80 dBA in noise showed no difference in hearing levels or DPOAE values at the moderate or high intensity levels. DPOAEs of the PLD user group were then examined. For the 27 participants who completed DPOAE testing, probe-microphone and PT testing, age was the only variable significant at the moderate (p = 0.0111). Contrary to our hypothesis, those who had used a PLD for a greater number of years were more likely to have better traditional frequency-band means when matched for age, than non-PLD users. However, for HF-band means of PLD users, variables found to significantly influence hearing levels included age, the use of hearing protection, and years listening to their device  and consistent use of hearing protection. Participants who “always” used hearing protection were found to have better thresholds in the high frequency range (p = 0.02) while those who inconsistently wore ear protection showed no significant effect on hearing thresholds. For non-PLD users, similar analyses were done on survey questions. Age was the only contributing variable found to impact traditional frequency-band means. For HF-band means, significant influences included age (p < 0.0001). Body Mass Index (BMI) was found to have a marginal positive correlation with traditional frequency-band means (p = 0.094). For the HF-band means, age (p < 0.0001) and W:H ratio (p = 0.04) were found to be contributing factors to hearing thresholds. W:H ratio was found to have a significant positive correlation with pure tone HF-band means (p = 0.004) after adjusting for age. A total of 105 participants completed both the audiologic and health-related fitness portions of the study. Ten participants were excluded for failing to complete both portions of the study. For the traditional frequency-band means, age was found to be a significant contributing factor . In this case, individuals that exposed themselves to more different types of noisy environments tended to have better hearing. One hypothesis for this finding is that this study examined the relationship between total number of environments and hearing acuity, rather than examining individual environments and their relation to actual mean intensity levels of each exposure environment. Furthermore, frequency and duration of exposure in each environment reported in the survey was not co-factored into the analysis. Future research should examine the link between hearing acuity and individual noise environments, while considering the frequency, intensity and duration of the noise exposure within each context. As seen in ing guns . Contraret al. who found that DPOAEs parallel deteriorations in PTTs and may worsen as a result of noise exposure [Superior HF Pure Tone Thresholds (PTT) were observed for the five PLD users who protected themselves from noise damage through consistent use of hearing protection. No changes were observed for participants that “sometimes” or “rarely” wore hearing protection. The most common environments for the use of hearing protection included during construction, at concerts and at shooting ranges. Future research should continue to explore the possibility of DPOAE values as indicators of future NIHL. Nonetheless, no differences in mean DPOAE values at moderate and loud intensity levels were observed between those with frequent noise exposure, and those with limited noise exposure in the current study. This is contrary to the results of Seixas exposure . When discussing the impact of PLD use on hearing, it is important to consider both the intensity and duration of listening. While NIOSH recommends a permissible exposure level of 85 dBA for 8 hours , the valConsistent with the belief that intensity levels above 80 dBA are harmful to hearing, participants in the current study who listened at levels above 80 dBA in silence had worse hearing thresholds than those who listened at safe levels . No diffet al. who found that 14% of young adults with long-term history of PLD use had hearing impairment. Of those participants with NIHL, incidence was highest in the subgroup that had been listening for five years, revealing that the risk of damage to hearing is increased as the length of listening time increases [Our findings indicate that PLD users who listen for greater than eight hours per week are at an increased risk for hearing loss compared with PLD users who listen less than eight hours per week. These results suggest that duration rather than intensity may increase subsequent risk of developing NIHL. This is consistent with the report of Meyer-Birsch who found that young adults who used their personal music system more than seven hours per week had poorer hearing thresholds compared with other young adults with less PLD use . Contrarncreases . A possir = 0.62) was found between hearing acuity and BMI (p = 0.09). BMI is an indicator of body fat composition taken from a person’s weight and height. It is calculated by dividing weight in pounds (lbs.) by height in inches (in) squared and multiplying by a conversion factor of 703. BMI values in the range of 18.5–24.9 are considered healthy while values above 25 are associated with being overweight or obese [Although researchers claim that high cardiovascular fitness positively influences the auditory system and in turn protects hearing sensitivity  the curror obese . While Bor obese . Increasor obese . As seenUsing the HF-band means, an association was found between hearing acuity and W:H ratio. Normal W:H ratio measurements are: ≤0.80 for women and ≤0.90 for men . As seen2 max was lower in the group of participants over the age of 50 compared with <50 year-old group, age became a more potent variable than VO2 max. In a separate study, Alessio and Marron reported that individuals with VO2 max values greater than 31 mL/kg/min for women, and greater than 34 mL/kg/min for men, reduced their susceptibility to metabolic and cardiovascular disease and also had better hearing acuity regardless of age [These findings support the conclusion that improved health-related fitness as indicated by healthy body composition in particular, is associated with superior hearing in the H-F band. Exposure to excessive noise affects the H-F sounds first. Nonetheless, the impact of high intensity noise on hearing may be minimized through regular exercise. It is hypothesized that high levels of health-related fitness reduce susceptibility to TTS by increasing blood flow and oxygen delivery throughout the body, including the ear . By imprs of age . This suThis study examined the relationship between hearing levels, listening habits of PLD users and cardiovascular health and fitness variables for adults aged 18 to 80. Age was found to be a significant predictor with traditional frequency-band thresholds, HF thresholds and DPOAEs. PLD user status did not impact hearing acuity. Nonetheless, PLD users who used their devices for longer than 8 hours/week were more likely to have worse hearing levels than PLD users who listened with limited duration. Furthermore, PLD users who listened at safe (<80 dBA) rather than dangerous (>80 dBA) intensities in silence had better traditional frequency-band threshold levels than those who listened at higher intensity volumes. Specific indices of health behavior appeared to influence hearing levels more than others. A healthier  BMI was marginally associated with favorable levels of traditional frequency-band thresholds, while a healthier  W:H ratio was strongly correlated with improved hearing in the high frequencies. It is well known that healthy levels of physical activity and cardiovascular fitness are inversely associated with BMI. Therefore, it is possible that physical activity and cardiovascular fitness may have less of a direct effect on hearing, but rather, indirectly influence hearing via physical activity-induced changes in BMI as well as other factors  known to influence hearing. In conclusion, the risk of developing NIHL over time is mediated by several audiological and non-audiological behaviors. One non-audiological behavior is health related fitness that may influence hearing thresholds. Although PLD use alone is not a major predictor of hearing thresholds, intensity and duration of listening may be significant indicators of hearing acuity.


Callithrix jacchus) in which one member of the pair was administered an intranasal OXT agonist, an OXT antagonist (OXTA), or saline. OXT treatment did not alter the expression of affiliative toward an untreated partner. However, OXT did significantly influence the expression of proximity and grooming behavior with a treated partner, as a function of OXT treatment and sex. Female interest in initiating and maintaining proximity with a pair-mate was altered by OXT treatment. Untreated female marmosets departed from their saline-treated partner more frequently than they approached them, as indicated by a low proximity index score. However, when males received an intranasal OXT agonist they had a significantly increased proximity index score relative to saline, indicating that their untreated partner approached them more often than they departed from them). Saline-treated females initiated and received equivalent levels of grooming behavior. However, when female marmosets were treated with an OXT agonist their untreated partner groomed them proportionately more often, for a greater total duration, and for more time per bout, than they initiated grooming behavior. These results suggest that intranasal OXT altered male and female marmosets’ stimulus properties in such a way as to increase the amount of grooming behavior that females received from their long-term mate, as well as increase female interest in initiating and maintaining proximity with their long-term mate. Furthermore, these results support the notion that central OXT activity plays an important neuromodulatory role in the maintenance of long-lasting male-female relationships.Adult male-female bonds are partly characterized by initiating and maintaining close proximity with a social partner, as well as engaging in high levels of affiliative and sociosexual behavior. Oxytocin (OXT), a neuromodulatory nonapeptide, plays a critical role in the facilitation of social bonding and prosocial behavior toward a social partner Feldman, . However Adult male-female bonds function to facilitate reproduction, and lessen detrimental health outcomes due to stress and anxiety in socially monogamous species Carter, . Thus, fThere is considerable evidence that the oxytocin (OXT) system plays a critical role in the facilitation of social bonds  in the “social brain”, less attention has been given to whether augmentation of OXT levels alters others’ perceptions and behavior Callithrix jacchus) are a highly social, cooperatively breeding New World primate that readily form and maintain long-term male-female relationships  is distinctly different than the consensus mammalian variant of OXT (Leu8-OXT), and results in a substantially altered structure in the “linear” portion of the molecule that likely affects OXT ligand-OXTR binding, and subsequently behavior. Recently, we demonstrated that Pro8-OXT, but not Leu8-OXT, influences the expression of social behavior in well-established marmoset pairs during behavioral tasks when an opposite-sex stranger was present. Pro8-OXT facilitated fidelity in female marmosets by reducing time spent in close proximity with, and sociosexual behavior toward, an opposite-sex stranger , housed at the Callitrichid Research Center (CRC) at the University of Nebraska Omaha, were employed in this study. Animals were 3.2 ± 0.2 (mean ± SEM) years of age at the start of the study, and were kept in large indoor wire-mesh enclosures (1.0 × 2.5 × 2.0 m), equipped with a sleeping hammock, natural branches for climbing and various enrichment materials. Visual access was restricted between enclosures, but auditory and olfactory cues were not. Colony rooms at the CRC were maintained on a 12 h: 12 h light: dark cycle and at a temperature range between 19°C and 22°C. For all dietary and husbandry protocols please refer to Schaffner et al. , a synthetic prostaglandin analog 3 days prior to each treatment period to synchronize females’ ovarian cycles by inducing luteolysis , Leu8-OXT , or saline 30 min prior to home-cage observations, via intranasal administration during a brief (~3 min) manual restraint. Intranasal administration was accomplished using a 100-μL Eppendorf pipette to administer 50-μL of solution to each nostril drop-wise (30 s between each nostril), and is a relatively well-tolerated, non-invasive method of administration.Marmosets were administered either saline or 25 IU  of one of two different OXT agonists, which yielded a dose of 150 μg/kg. The dose was determined based on previous primate literature  to access the central nervous system (CNS) via the olfactory bulb and the maxillary branch of the trigeminal nerve  is readily absorbed by the bloodstream after passage through the digestive system ] yielded scores from 0+ where a score > 1 indicates that marmosets approached their partner more frequently than they departed from them and a score < 1 indicates that marmosets departed from their partner more frequently than they approached them. The derived grooming indices  yielded scores from –1.0 to +1.0, where +1.0 indicates that treated marmosets received all of the grooming behavior and –1.0 indicates that treated marmosets initiated in all of the grooming behavior. We used a similar calculation to create derived variables for total grooming duration and time spent grooming per bout. To account for within-pair interactions, these indices take into account the direction of the behavior of both the treated and untreated individual within the dyad. Consequently, the analysis of these indexes assesses the mean behavior of the interaction between two members of a dyad across OXT conditions. We are then able to extract the behavior of a particular individual by evaluating the change in the direction of the index variable relative to saline. The effect of sex and neuropeptide treatment  on social interactions with a pair-mate was evaluated using several mixed-model analyses of variance (ANOVAs). If main effects or interactions were significant, post-hoc comparisons were made using Fisher’s least significant difference. All alpha levels were set at p < 0.05.To assess the possible effects of OXT treatment on patterns of sociality, data from home-cage observations were averaged across the 4 days of treatment for each treatment period to create a composite score. Raw values of proximity behavior , and grooming behavior  were scored and analyzed for males and females in conditions when their pair-mate was treated and in conditions when they were treated. Several indices were also derived to assess whether males and females were proportionately more responsible for initiating and maintaining proximity with a treated partner, and whether treated males and females received proportionately more or less grooming from an untreated partner. The derived proximity index [i.e.,  = 1.23, p > 0.05, η2 = 0.13); nor did OXT treatment interact with sex to modulate proximity behavior  = 0.70, p > 0.05, η2 = 0.08). Yet, marmosets initiated and maintained proximity with their treated partner as a function of OXT treatment and sex  = 3.25, p = 0.037, η2 = 0.27). Untreated female marmosets departed from their saline-treated male partner more frequently than they approached them (t(5) = −3.59, p = 0.016), as indicated by a low proximity index score. However, males that received an OXT treatment had significantly increased proximity index scores, relative to saline  = 3.66, p = 0.044, η2 = 0.48; Figure 8-OXT (t(5) = 3.86, p = 0.012), and moderately, but not significantly, increased in males that received Leu8-OXT (t(5) = 2.02, p = 0.10), relative to saline. OXTA-treated males did not have significantly different proximity index scores than saline-treated males (t(4) = 1.51, p = 0.21). Males did not alter the relative rate that they approached/departed from OXT-treated female partner, relative to their saline-treated female partner  = 1.30, p > 0.05, η2 = 0.21; Figure OXT treatment did not significantly influence how often a marmoset approached or departed from an tner  = 6.13, p = 0.005, η2 = 0.50). Saline-treated females initiated and received equivalent levels of grooming behavior (t(4) = 1.40, p = 0.23). However, when female marmosets received an OXT treatment they had a significantly increased grooming index score relative to saline  = 9.12, p = 0.002, η2 = 0.70; Figure 8-OXT (t(4) = 5.17, p = 0.007) or Leu8-OXT (t(5) = 7.91, p = 0.001) received grooming behavior proportionately more often than they initiated grooming behavior. Grooming index scores were significantly increased in females that received Pro8-OXT (t(4) = 3.58, p = 0.023) or Leu8-OXT (t(5) = 3.19, p = 0.024), and moderately, but not significantly, increased when females received an OXTA (t(4) = 2.67, p = 0.06), relative to saline. Female marmosets that received an OXT treatment also had a significantly increased grooming index score for total duration  = 5.37, p = 0.014, η2 = 0.57), and time per grooming bout  = 4.92, p = 0.019, η2 = 0.55), relative to saline. Males that received an OXT treatment did not display a proportionate change in the relative frequency  = 0.75, p > 0.05, η2 = 0.27; Figure F = 1.03, p > 0.05, η2 = 0.34), or time per bout  = 1.72, p > 0.05, η2 = 0.46) that they received vs. initiated grooming behavior. Furthermore, males  = 0.89, p > 0.05, η2 = 0.15) and females  = 0.64, p > 0.05, η2 = 0.11) did not display changes in the frequency that they solicited grooming from their pair-mate when they were administered an OXT treatment. See Table Marmosets also initiated and received grooming behavior differentially as a function of OXT treatment and sex  = 0.39, p > 0.05, η2 = 0.05) and time per proximity bout  = 0.54, p > 0.05, η2 = 0.05) were unaffected by OXT treatment and sex of the individual. Overall levels of huddling duration  = 0.54, p > 0.05, η2 = 0.05) and time per huddling bout  = 0.82, p > 0.05, η2 = 0.08) were also unaffected by OXT treatment and sex of the individual. Male and female sexual-solicitation behavior , male mating behavior , and territorial behavior  did not vary as a function of OXT treatment  when treated with OXT, suggesting that their untreated partners may be responding to more subtle social signals. It is well known that marmosets have highly-attuned olfactory systems and utilize scent as a means of social communication Epple, . There iOverall levels of grooming behavior were only moderately increased as a result of OXT treatment. However, the more noteworthy finding was that the rate an OXT-treated individual received grooming from their partner, relative to how often they initiated grooming behavior themselves, changed as a result of OXT treatment. Females treated with OXT initiated slightly less grooming and received slightly more grooming. Marmosets may maintain long-term bonds by expressing high-levels of affiliative behavior; they may be highly attuned to changes in the frequency and duration of grooming, as there may be an optimal level that is necessary to maintain a long-lasting bond. Thus, another possible explanation for OXT-related changes in affiliative behavior is that marmosets were responding to changes in the social dynamics of the relationships, and changed their behavior accordingly. Alternatively, OXT may increase the salience of their social partner, which may make them more trusting , as well as the consensus-mammalian variant (Leu8) of OXT. The frequency that females initiated grooming, relative to received grooming, was also influenced by both OXT agonists. Thus, there is converging evidence that both the consensus-mammalian variant of OXT  the acute nature of administration ; (2) the length of the relationship at the time of treatment; or (3) the pharmacological properties of the OXTA  awarded to Jeffrey A. French, and by funds from University of Nebraska Omaha’s Graduate Research and Creative Activity Committee awarded to Jon Cavanaugh.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.


Healthy hearing depends on sensitive ears and adequate brain processing. Essential aspects of both hearing and cognition decline with advancing age, but it is largely unknown how one influences the other. The current standard measure of hearing, the pure-tone audiogram is not very cognitively demanding and does not predict well the most important yet challenging use of hearing, listening to speech in noisy environments. We analysed data from UK Biobank that asked 40–69 year olds about their hearing, and assessed their ability on tests of speech-in-noise hearing and cognition.About half a million volunteers were recruited through NHS registers. Respondents completed ‘whole-body’ testing in purpose-designed, community-based test centres across the UK. Objective hearing (spoken digit recognition in noise) and cognitive  data were analysed using logistic and multiple regression methods. Speech hearing in noise declined exponentially with age for both sexes from about 50 years, differing from previous audiogram data that showed a more linear decline from <40 years for men, and consistently less hearing loss for women. The decline in speech-in-noise hearing was especially dramatic among those with lower cognitive scores. Decreasing cognitive ability and increasing age were both independently associated with decreasing ability to hear speech-in-noise  among the population studied. Men subjectively reported up to 60% higher rates of difficulty hearing than women. Workplace noise history associated with difficulty in both subjective hearing and objective speech hearing in noise. Leisure noise history was associated with subjective, but not with objective difficulty hearing.Older people have declining cognitive processing ability associated with reduced ability to hear speech in noise, measured by recognition of recorded spoken digits. Subjective reports of hearing difficulty generally show a higher prevalence than objective measures, suggesting that current objective methods could be extended further. The DTT choice of single digit words promotes easy understanding and the opportunity to ‘fill-in’ missed acoustic information, while steady-state, speech-shaped noise enables masking across the speech range, but does not allow the ‘glimpsing’ that can reduce masking in more complex noise. Overall, DTT performance correlates more closely with PTA than do some other SiN tests Self-report of hearing difficulties, using questionnaire instruments or often only one or two questions, has commonly been used to assess the prevalence of hearing loss in large epidemiological studies In this study we investigated the relation between DTT SRT and cognitive ability as a function of age, sex, socioeconomic status, and noise exposure. The results were compared with self-report of hearing difficulties and findings from other studies, including some previously unpublished data from the NIH Toolbox www.ukbiobank.ac.uk.Complete details of all UK Biobank procedures are available at This research was covered by the UK Biobank ethics agreement. Within England, UK Biobank has approval from the North West Multi-centre Research Ethics Committee (MREC). All participants provided written informed consent.Participants , about one third of the participants  of cards showing 3 and 6 pairs of shapes, respectively. The shapes were concealed and the participant was required to recall locations of matching shape pairs. Correct responses were confirmed. The Reaction Time test of processing speed sequentially presented twelve pairs of shapes. The participant pressed a button as quickly as possible if a pair of shapes matched. Finally, in the Digit Span (‘Numeric memory’) test of verbal working memory participants were initially presented on the screen with two digits and were required to key in the digits in reverse order. After each correct response the digit sequence was increased by one. The task ended after two incorrect responses. Raw score was the maximum number of correctly recalled and ordered digits. Performance on the Prospective Memory, Reaction Time and Digit Span tests additionally depended on executive function and all tests depended on alerting and orienting attention.Variable numbers of participants completed each test , primariAnalysis of self-report measures used binary logistic regression. Standardised scores, which each maximised the variability within the sampled population, were derived for each cognitive test using principal components analysis. A composite score was defined as a simple sum of the five standardised scores. Both individual and composite cognitive scores were standardised to have zero mean and unit standard deviation, such that higher values corresponded to higher ability. Scores were grouped into deciles for analysis. Regression modelling techniques accounting for sex, socio-economic deprivation  tone detection thresholds declined from 18–85 years (NIH Toolbox data (DOCX)Click here for additional data file.


As the amount of scientific data grows, peer-reviewed Scientific Data Analysis Resources (SDARs) such as published software programs, databases and web servers have had a strong impact on the productivity of scientific research. SDARs are typically linked to using an Internet URL, which have been shown to decay in a time-dependent fashion. What is less clear is whether or not SDAR-producing group size or prior experience in SDAR production correlates with SDAR persistence or whether certain institutions or regions account for a disproportionate number of peer-reviewed resources.We first quantified the current availability of over 26,000 unique URLs published in MEDLINE abstracts/titles over the past 20 years, then extracted authorship, institutional and ZIP code data. We estimated which URLs were SDARs by using keyword proximity analysis.-4). Approximately 3.4% of URLs, as published, contain errors in their entry/format, including DOIs and links to clinical trials registry numbers.We identified 23,820 non-archival URLs produced between 1996 and 2013, out of which 11,977 were classified as SDARs. Production of SDARs as measured with the Gini coefficient is more widely distributed among institutions (.62) and ZIP codes (.65) than scientific research in general, which tends to be disproportionately clustered within elite institutions (.91) and ZIPs (.96). An estimated one percent of institutions produced 68% of published research whereas the top 1% only accounted for 16% of SDARs. Some labs produced many SDARs (maximum detected = 64), but 74% of SDAR-producing authors have only published one SDAR. Interestingly, decayed SDARs have significantly fewer average authors (4.33 +/- 3.06), than available SDARs (4.88 +/- 3.59) (p < 8.32 × 10SDAR production is less dependent upon institutional location and resources, and SDAR online persistence does not seem to be a function of infrastructure or expertise. Yet, SDAR team size correlates positively with SDAR accessibility, suggesting a possible sociological factor involved. While a detectable URL entry error rate of 3.4% is relatively low, it raises the question of whether or not this is a general error rate that extends to additional published entities. Becausehttp://webcitation.org[http://www.neuinfo.org/) [Internet-accessible resources, locatable by their Uniform Resource Locator (URL) addresses, are being increasingly used in scientific publications. However, unlike print, URLs are dynamic and can not only change in their content but become inaccessible. This phenomenon, URL decay, whereby URLs become inaccessible in a time-dependent manner, has been documented in numerous studies to date and has been reported across academic disciplines  -6. Theseation.org, and othfo.org/)  to identHere, we are interested in a related phenomenon - factors that are associated with historical SDAR production and whether or not any of them are also correlate with eventual decay. For example, does the number of authors publishing a SDAR correlate with its stability? In terms of vigilance in maintaining the online presence of SDARs, there are several possibilities as to what factors are most effective with reference to the original team creating the SDAR. It's possible that online stability correlates with the number of authors on the paper - perhaps because there might be more people with a vested interest in its maintenance and more people able to maintain it. Or, perhaps more authors might dilute the perception of personal responsibility for SDAR decay, and thus fewer authors per paper might lend itself to greater SDAR stability. What is the distribution in SDAR production by institution and does it differ from scientific research in general? How many groups publish multiple SDARs and are their SDARs more or less likely to be accessible? Alternatively, SDAR decay may be more a function of external factors, such as whether a project to create the SDAR was underfunded, a hosting institution changing policies regarding external access of internal network content, or a lack of interest from the scientific community in using the SDAR.An interesting corollary to these questions is to contrast SDARs with the biomedical literature in general from an economic perspective. If publications are the currency of academia, can we measure the "health" of its economy? To that end, the Gini coefficient (aka the Gini index or Gini ratio) has been employed as a measure of wealth disparity by economists and sociologists to reflect the contrast between the richest and poorest in a nation. Ranging from 0  to 1 , it is defined as the coefficient between the area below a Lorenz Curve  and the area between it and the line of equality  . By contAll of the extracted data, including MEDLINE URLs, abstracts, author names, dates and institutions, were obtained from the May, 2014 release of the National Library of Medicine's MEDLINE XML dataset . To prevAffiliation element, using the "extract_data.py" program, primarily using heuristics and regular expressions. One of the primary goals in extracting the names was to find the most generic identifier that uniquely pertained to an entity so that we could focus on discussing institutions, though this was challenging due to different punctuation, spelling, abbreviations and languages. The Affiliation string was first tokenized using commas, after which a prioritized set of keywords were searched within the substrings to identify high-level entities. Due to the noisy nature of the data, all institutions only appearing once were excluded from analysis.Institution names and their ZIP codes pertaining to individual citations were extracted from the Attempts were made to handle the international and multilingual nature of biomedical publishing. Some keywords were introduced to cover their English equivalents  and "Istituto" ), while others only needed to be shortened due to their common lingual history . Unicode text was reduced to its closest English transliteration using the unidecode python package as it was observed that names with non-English characters were inconsistently translated already. All comparisons were done in a case-insensitive manner.Various functions of standardization were applied (such as eliminating a leading "The"), the most controversial of which would likely be the dropping of any text after "University" if there was text before it. This reduced names such as "Foo University School of Medicine" down to "Foo University" while leaving others like "University of Foo" as they were. This forced judgment calls to be made in terms of what constitutes an institution, like in the case of the most represented institution, the University of California system, which is managed by a central board of regents. At the same time, there are many researchers at universities who list their college  as their primary entity, making it difficult to fold them back into their university. With over 12 million institute strings, each heuristic added also has the potential to introduce a new parsing error.ZIP codes were extracted simply by verifying that an entry looked somewhat USA-related (containing "USA" or "United States" or at least not containing another country's name) and looking for a 5 digit number, preferably toward the end of the string.URLs were extracted from the XML abstracts using a Visual Basic program as described in . To detehttp://code.google.com, http://sourceforge.net, etc). This was done on the basis of the top-level domain (TLD). For example, URLs pointing to Digital Object Identifiers (DOIs), http://Webcitation.org, http://ClinicalTrials.gov, and journal-based archive sites were separated out and excluded from the rest of the URLs. These URLs (particularly DOIs) are expected to be more stable due to their long-term organizational support.For analysis purposes, we separated out 2,529 websites , but dozens of publications have misspelled the URL. For example, hyphenating clinical-trials , misspelling "trials" as "trails", but most often just not correctly formatting the URL. What fraction may be the fault of the authors, the journal publication process or entry into MEDLINE is not known.Interestingly, of the 666 DOIs detected, 19 (3%) were inaccessible. Although a very low rate, the very idea behind DOIs is to provide a permanent locator. Upon further examination, nine contained apparent spelling/formatting errors, 4 of which could be corrected and were then accessible. The other 5 were missing a critical field standard to DOI formatting, but what the field should have been could not be determined. The remaining 10 may have also had spelling errors but, if so, were non-obvious. Furthermore, this 3% erroneous entry rate seemed to be a general phenomenon, as 85 of the 2,529 archival URLs (3.4%) were inaccessible. Manual inspection of the URLs (as extracted and as written in PubMed) showed that many of them were incorrectly formatted. For example, two links to the archival site ation.org left offAfter excluding archival URLs, there were 23,820 unique URLs found between 1996 and 2013  than those that have published only one. There are competing hypotheses as to whether or not publication of multiple URLs correlates with greater or lesser stability. On one hand, senior authors that produce many SDARs likely have focused on developing the necessary infrastructure and have likely dedicated a substantial portion of their research to providing SDARs. On the other hand, a researcher publishing multiple SDARs might have a single point of failure  or simply have too many to effectively keep track of.We identified 6,600 unique senior author names associated with one or more SDARs. A total of 2,279 of these senior authors had published multiple SDARs, the top 25 of which are shown in Table Scientific papers tend to be disproportionately produced by a relatively small fraction of institutions, which tends to be a function of infrastructure and resources. We were curious whether or not the distribution in production of SDARs differed from that of publications in general. After parsing out institution names (see methods), 68% of MEDLINE publications came from 1% of institutions, which stands in stark contrast to institutions producing SDARs where the top 1% of paper-producing institutions only produced 16% of SDARs. As a comparison point and as a check on the text processing of institutional data, a geographical comparison using ZIP codes for US-based locations were also extracted and tested, in part because they are simpler and thus more reliable to parse (though ZIP codes can change over time). Similar to the institutional data, we found that the top 1% of ZIP codes produced 71% of publications, while 1% of SDAR-producing ZIP codes accounted for 12% of the total. Illustrating these findings, Figure Many of the top publication-producing institutions and ZIP codes did not come as a surprise as they are widely known and respected in the biomedical world and can be seen in Tables Gini function in R's ineq package [µ is the mean number of publications for all entities:The Gini coefficient, widely used among social scientists and economists, gives us a useful tool in quantifying the aggregation of publications. For both of the measures we looked at , it was clear that a large proportion of biomedical publications come from a very small percentage of locations. Likewise, while still high relative to most countries, the distribution of URL-producing locations was consistently more distributed than publications overall. Among MEDLINE-publishing institutions, the coefficient stood at .91 while for those producing SDARs it was .62. Compared to institutions, the geographically-based coefficients were both higher, at .96 for all publications and .65 for those producing SDARs. To get a comparative sense of magnitude for the Gini coefficients, it can be helpful to look at contemporary world economies. As of 2014, they range from a low of .25  to a high of .66. The method used for calculating these Gini coefficients was the  package . The coe package ), where -11) 0.2% increase per year and ZIP codes not having a significant change. SDAR-publishing concentration seems to be on the rise, however, with a 1.2% annual increase among institutions significant at the 3.2 × 10-5 level and 1.9% increase for publishing ZIPs, significant at the 5.8 × 10-6 level. A graph of these values can also be seen in Figure Given the relatively recent introduction of Internet-based resources into academic publishing, an interesting question to ask is whether their relatively lower concentration when compared to publications overall is a temporary phenomenon. That is, whether SDARs will eventually become more concentrated within a relatively few institutions. To do this, we examined the trajectory of concentration over time by calculating an annual Gini coefficient and looking for a pattern. To that end, four simple linear models were fit for each year from 1996 until 2013 using every combination of location entity (institution or ZIP) and published metric . Publications overall appear to show little movement in their annual Gini coefficient, with institutions showing a very slight . Three of the four most cited papers in all of science within the past 25 years have reported the development of SDARs, which speaks to the extent to which they have influenced research. But the continued accessibility of SDARs remains an issue. We sought here to examine some of the factors related to production and stability of SDARs, such as the size of the scientific laboratories that produce them, a lab's general proclivity to produce SDARs as part of their research focus, and the general distribution of SDAR production among institutions.We find the average number of authors per accessible SDAR is significantly higher than the average number per inaccessible SDAR. There were no substantial outliers in the data that biased the average , so there are several possible explanations. The first is that, perhaps, authors who create SDARs also tend to be users of them and therefore more people tend to have a personal interest in its continued availability. A second possibility may be more sociological in that the more authors per SDAR, the more people there are to contact about its decay, to be vigilant about its accessibility, or to provide options if the primary maintainer becomes unable to maintain it . It is also possible that larger projects that involve more people also tend to result in a more useful and/or stable end-product.The distribution of SDAR production suggests that bioinformatics may occupy somewhat of a unique niche among scientific disciplines, as it does not require extensive infrastructure to develop and deploy analysis software. Specialized institutions such as the European Bioinformatics Institute are able to make substantial contributions while not being among the top general players. Consequently, published SDARs can be produced from institutions that lack the resources of more elite institutions. However, whether the SDARs from elite institutions are more stable or more cited is not known and will be the subject of future study.With a slow but steady annual rise in the Gini coefficient for SDARs, the data may be hinting that this more distributed state of affairs could be gradually approaching the more centralized production of biomedical research. Perhaps nimble early adopters contributed substantially to efforts and now that waning? It may also be that as the novelty of developing and sharing digital analysis resources wears off, large and more established organizations are venturing into that arena, a model that has been suggested for Internet technology in general.http://Webcitation.org), and should be accessible, we found that a number of published errors have crept into the scientific record, at an approximate rate of 3%. Although this is a relatively low rate, it begs the question of how extensively it permeates reported entities such as numbers , record identifiers, and names. Variation in URL construction is consistent with other reported variation such as the creation of acronym-definition pairs [Finally, by identifying which URLs should be stable on the basis of their support by organizational entities . We found average team size for SDAR production tends to be lower than scientific publications in general, although larger team size correlated with SDAR persistence. SDAR production is less dependent upon institutional location and resources, as judged by the Gini coefficient, and groups producing multiple SDARs do not seem to differ in the probability they are still accessible from groups that have produced only one SDAR. Finally, errors are creeping into the public record at a rate of about 3%, rendering their URLs, as written, invalid from the moment of publication.The authors declare that they have no competing interests.The authors would like to acknowledge the National Science Foundation (NSF) for funding this research and publication from grant # ACI-1345426.Breakdown in % availability for the URLs queried.Click here for file


Permanent childhood hearing loss affects 1 to 3 per 1000 children and frequently disrupts typical spoken language acquisition. Early identification of hearing loss through universal newborn hearing screening and the use of new hearing technologies including cochlear implants make spoken language an option for most children. However, there is no consensus on what constitutes optimal interventions for children when spoken language is the desired outcome. Intervention and educational approaches ranging from oral language only to oral language combined with various forms of sign language have evolved. Parents are therefore faced with important decisions in the first months of their child’s life.This article presents the protocol for a systematic review of the effects of using sign language in combination with oral language intervention on spoken language acquisition. Studies addressing early intervention will be selected in which therapy involving oral language intervention and any form of sign language or sign support is used. Comparison groups will include children in early oral language intervention programs without sign support. The primary outcomes of interest to be examined include all measures of auditory, vocabulary, language, speech production, and speech intelligibility skills. We will include randomized controlled trials, controlled clinical trials, and other quasi-experimental designs that include comparator groups as well as prospective and retrospective cohort studies. Case-control, cross-sectional, case series, and case studies will be excluded. Several electronic databases will be searched  as well as grey literature and key websites. We anticipate that a narrative synthesis of the evidence will be required. We will carry out meta-analysis for outcomes if clinical similarity, quantity and quality permit quantitative pooling of data. We will conduct subgroup analyses if possible according to severity/type of hearing disorder, age of identification, and type of hearing technology.This review will provide evidence on the effectiveness of using sign language in combination with oral language therapies for developing spoken language in children with hearing loss who are identified at a young age. The information from this review can provide guidance to parents and intervention specialists, inform policy decisions and provide directions for future research.CRD42013005426 Population-based newborn hearing screening has become a standard of care in the developed world to improve the developmental outcomes for children with permanent hearing loss -3. ChildHistorically, there has been a debate about what constitutes desirable outcomes for children with hearing loss and a plethora of intervention/education programs have evolved. These programs can be grouped into two distinct philosophies: one focused on fostering spoken language development and inclusion with normal hearing peers; and the other on communication using primarily a visual approach  and promoting a sense of identity with a Deaf culture ,16. EpidDespite a growing body of evidence that children with hearing loss can develop oral language skills ,18,19, tFrom a theoretical perspective, research in neuroplasticity and critical periods of learning ,22 lend Further complicating the issue for parents is the growth of the use of signs, commonly known as “baby sign language” with typically developing babies. This practice raises further questions about whether the addition of signs might promote spoken language acquisition in children with impaired hearing. A systematic review  found noThe uncertainty surrounding the most appropriate interventions required to achieve age-appropriate language skills is one of the major challenges facing newborn hearing screening initiatives. This review is timely because there has been a proliferation of newborn hearing screening programs worldwide in the past 10 years. In addition to early identification, early cochlear implantation “which involves electrical stimulation of the auditory system” has had a dramatic impact on improving the spoken language potential for children with severe to profound deafness. There is good evidence for positive spoken language outcomes from the cochlear implant literature ,25,30 buAccordingly, the primary purpose of this research is to connect researchers and knowledge users to examine the evidence for the effects of various treatment options for early-identified children with hearing loss when the desired outcome is spoken communication. The major question addressed in this proposal is specific to the components or characteristics of the intervention and the auditory and spoken language capacity of the developing child. A review undertaken in 2008 to update the United States Preventive Services Task Force recommendations on newborn hearing screening highlighted the need for further research to demonstrate the effectiveness of the entire process of screening to intervention  for the study selection process.Once all records have been retrieved through electronic and other searching methods, they will be compiled in a Reference Manager database and checked for duplication. All remaining citations will then be exported to the Distiller Systematic Review Software (DSR), an internet-based software program [The study selection involves two specific stages. Screening forms will be developed from the inclusion and exclusion criteria and calibrated among reviewers with a subset of records before each screening stage takes place.Titles and abstracts will be assessed by one reviewer for potential relevance; a second reviewer will verify those records deemed not relevant.Two independent reviewers will screen all potentially relevant full-text articles. Disagreements will be resolved by consensus or by consultation with a third member of the research team when needed.Electronic study-specific data abstraction forms will be used to abstract pre-determined data for each study. Data will be collected and managed in DSR. Data abstraction items will broadly include: 1) study characteristics ; 2) study design; 3) population characteristics - for example, sample size, sex, ethnicity, etiology (including radiologic findings when available), age of hearing loss identification and intervention, severity of hearing loss, type of hearing technology, time with hearing technology, parental involvement, socio-economic status, home/intervention language, cognitive status; 4) details of intervention (including fidelity); 5) details of control or comparison groups (including fidelity); 6) risk of bias assessments; and 7) outcome definitions and data. The data abstraction form was finalized with input from the knowledge users at the first team meeting. One researcher will extract all information; a second reviewer will verify all information. Discrepant findings will be resolved through consensus or a third reviewer when required.If information or data are missing or incomplete, we will attempt to contact the study authors twice through email over a 4-week period. We will not impute data for any outcomes.The risk of bias assessment will be conducted by one researcher with full verification by a second researcher. For randomized and controlled clinical trials, the Cochrane Risk of Bias tool  will be Study characteristics will be summarized narratively in the text and/or in tables in the report; data may be presented as frequencies and percentages, medians and interquartile ranges, or means and standard deviations, where appropriate. A narrative synthesis of the evidence will be conducted when quantitative pooling of data is not possible. Based on previous reviews ,37,38 thpost hoc, subject to the body of evidence available. For any time-to-event data, the generic inverse variance method will be used to meta-analyze outcomes using log hazard ratios and standard errors. When required, we will convert data  to facilitate analyses and consistency in the presentation of study findings. Statistical heterogeneity will be evaluated using I-squared (I2) statistics; for the interpretation of I2, a rough guide of low (0-25%), moderate (25-50%), substantial (50-75%), and considerable (75-100%) heterogeneity will be used; possible reasons contributing to heterogeneity will be explored. If there is considerable heterogeneity (>75%), we will not complete a pooled analysis. If data permit, sensitivity analyses may be undertaken with respect to risk of bias (restricting to studies with low risk of bias), the fidelity of the intervention, data issues, or measurement of outcomes. If at least 10 studies are included in a meta-analysis, funnel plots will be generated to assess for publication bias and other possible reasons for asymmetry [If, based on clinical similarity, quantity, and quality, meta-analysis is possible for some outcomes, we will use a random effects model to generate aggregate results. For continuous data we will compute mean or standardized mean differences with 95% confidence intervals (CIs). Any change-from-baseline data will be collected in addition to final data. Risk ratios with 95% CIs will be computed for dichotomous data. Decisions about handling and analyzing ordinal outcomes will be determined symmetry .We will examine the following variables in subgroup analyses as effect modifiers, if feasible: 1) severity of hearing loss ; 2) children with auditory neuropathy; 3) age of identification of hearing loss ; and 4) children with hearing technology .P < 0.01.If appropriate and with sufficient, complete data, we will verify results of the subgroup analyses with univariate meta-regression. The variables outlined above for subgroup analyses will be considered statistically significant at We will apply methodology developed by the Grades of Recommendation Assessment, Development and Evaluation working group  to rate Reporting of the review findings will follow guidelines for reporting systematic reviews presented in the PRISMA statement . The repThe principal objective of this review is to understand the effects of using sign language as a support for spoken communication development of children with hearing loss. This project represents collaboration between researchers and three knowledge users representing parents, health and education provider groups with a broad reach, who bring complementary but distinct expertise and strengths that will facilitate knowledge translation. Intervention decisions and parent guidance tend to be based on single studies without attention paid to the quality of the evidence and the particular characteristics of the study population. The expected outcome of partnering closely with end-users is to eliminate some of the potential pitfalls in the way that evidence is interpreted and used. We envision that knowledge translation will take place continually through natural networks and outreach activities, as knowledge users familiarize themselves with the relevant literature and the results of this systematic review. Planned activities include in-service professional meetings, a parent conference presentation, parent information pamphlet, presentation at scientific conferences, peer-reviewed publication, and the integration of the results into academic seminars and coursework.Infant hearing screening continues to occupy an important place on national and international agendas as a population health intervention aimed at improving communication development for children with permanent hearing disorders. Hearing screening has received widespread support on the basis of the burden of the disorder to society and the assumption that early intervention can prevent or reduce delays in language development. However, there remains considerable uncertainty and disagreement about what constitutes optimal treatments for the current generation of early-identified children with hearing loss. Successful implementation of evidence into the pediatric hearing field has been difficult to achieve with the end result that unbiased information is not readily available to parents. Consequently, parents are forced to make decisions about care based on unclear and potentially biased evidence when their children are diagnosed in infancy.This systematic review aims to become an important information tool for parents, clinicians, researchers, and decision-makers who need new evidence that is accumulating in the field of newborn screening and early intervention outcomes. Our goal is that this review will contribute to a better understanding of treatment effects, leading potentially to a timelier introduction of the most effective interventions that are aligned with parents’ desired outcomes for their children with hearing loss. Through a knowledge-user and researcher partnership, we will create a common understanding of the goals, use a common terminology, and assemble the best possible evidence to provide care to the “new” populations of children with early-identified hearing loss.This review was motivated by questions and concerns at the clinical practice level of providing services for young children. One potential byproduct of this review is the development of clear research needs for the scientific community grounded in the experiences of the knowledge users. In the long-term, we envision that the findings resulting from this collaboration that spans healthcare, education, and graduate training will help to further define appropriate questions for future collaborative research to address childhood hearing loss issues in a field wrought with anecdotal reports and expert opinion. Accordingly, this review is expected to provide a foundation for ongoing and new scientific enquiry to more effectively assist families affected by childhood hearing loss and to optimize health services.ASL: American Sign Language; CI: Confidence interval; DSR: Distiller Systematic Review Software; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols.The authors declare that they have no competing interests.EMF conceived the project and is the guarantor. EMF, AS, CG, and DM developed the methods. EMF drafted the protocol. All authors reviewed and approved the final version.EMF is Associate Professor in the Audiology and Speech-Language Program, Faculty of Health Sciences at the University of Ottawa and Senior Scientist at the Children’s Hospital of Eastern Ontario Research Institute. AS is Senior Clinical Research Associate, Knowledge Synthesis Group, Centre for Practice-Changing Research, Ottawa Hospital Research Institute. CG is Senior Research Program Manager, Knowledge Synthesis Group, Centre for Practice-Changing Research, Ottawa Hospital Research Institute. DM is Associate Professor, Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa and Senior Scientist, Clinical Epidemiology, Ottawa Hospital Research Institute.MEDLINE Search Strategy.Click here for file


The capacity of visual working memory (VWM) refers to the amount of visual information that can be maintained in mind at once, readily accessible for ongoing tasks. In healthy young adults, the capacity limit of VWM corresponds to about three simple objects. While some researchers argued that VWM capacity becomes adult-like in early years of life, others claimed that the capacity of VWM continues to develop beyond middle childhood. Here we assessed whether VWM capacity reaches adult levels in adolescence. Using an adaptation of the visual change detection task, we measured VWM capacity estimates in 13-year-olds, 16-year-olds, and young adults. We tested whether the capacity estimates observed in early or later years of adolescence were comparable to the estimates obtained from adults. Our results demonstrated that the capacity of VWM continues to develop throughout adolescence, not reaching adult levels even in 16-year-olds. These findings suggest that VWM capacity displays a prolonged development, similar to the protracted trajectories observed in various other aspects of cognition. The capacity of visual working memory (VWM) refers to the amount of visual information that can be maintained in the mind at once, readily available for rapid access . It has While superior performance in VWM tasks has been associated with favorable cognitive and educational outcomes, deficits in VWM have been observed in learning disabilities in reading  and mathSeveral studies focused on investigating the typical developmental trajectory of VWM capacity. One of the common paradigms used in these developmental studies is the visual change detection task . In thisVariants of this paradigm were employed in infant studies to investigate the development of VWM during the first year of life . For insHowever, contrary to the assertions that VWM capacity develops rapidly to the extent that it reaches almost adult levels in infancy, several studies argued a more protracted development, continuing at least through childhood. For instance, in a study with an adaptation of the change detection task for young children, 3- and 4-year-old children had lower VWM capacity estimates compared to 5- and 7-year-old children, and 5-year-olds performed significantly worse than 7-year-olds . In a siFurthermore, while In the present study, we investigated whether VWM capacity shows a protracted development, extending from adolescence into adulthood. Adolescence is a time period during which the brain exhibits tremendous structural changes . The corTo investigate whether VWM capacity reaches adult levels in early or later years of adolescence, we recruited 13- and 16-year-old participants. Adolescent participants were recruited via the developmental database of the University of Oregon. All adolescent participants were middle school and high school students, attending a variety of schools in Eugene, Oregon. Parents were interviewed over the phone to ensure their children had normal or corrected-to-normal vision and were typically developing individuals with no neurological disorders, developmental delays, ADD/ADHD, learning disabilities, visual tracking problems, color blindness, depression or anxiety, and had never used any psychotropic drugs.Adult participants were recruited via flyers from the University of Oregon. All adult participants were students at the university. Prior to participation, they were interviewed to ensure that they met all the criteria that were used to recruit adolescent participants.M = 13.49 years; SD = 0.30; 13 females), twenty-two 16-year-olds , and 23 adults . One 13-year-old participant was not included in this final sample for performing below chance at higher set sizes, suggesting a high likelihood that this participant was not fully engaged in the task.The sample included three age groups: twenty-two 13-year-olds  = 0.85, p = 0.43].Maternal education levels were compared as a proxy for socio-economic status (SES). The mean maternal education level corresponded to “completed some college classes” across the age groups, which is the equivalent of some education beyond 12th grade and attendance to any post-secondary institution in the United States. No differences in maternal education were observed between groups .For the Replicating previous findings with young adolescents , this exExperiment 1 provided confirmatory evidence that the estimates of VWM capacity do not reach adult levels in early adolescence, and the first evidence that they may not reach adult levels even in late adolescence. These results contradict the claims that VWM capacity reaches adult-levels during early years of life. However, it is possible that the discrepancy of findings between these studies is at least partially driven by differences in the duration of memory arrays. In the studies that claimed the VWM capacity reached adult levels in early years of life , the memThere are contradictory findings on the effects of increased presentation time on VWM performance. In a study with young adults, increasing the duration of the memory array from 100 to 500 ms was not found to improve VWM performance . On the In this experiment, we explored the effects of the duration of the memory array on VWM in adolescents and adults. We aimed to replicate the findings of Experiment 1 and also determine (a) whether the adolescents benefited more than adults from longer exposure times; and (b) whether the increase in exposure to the memory array was sufficient to eliminate the age differences in performance observed in the first experiment. In order to examine the effects of exposure time on the VWM performance of adolescents and adults, we presented the participants with memory array durations of 150, 500, and 1000 ms, randomly presented across trials. We did not use a presentation time longer than 1000 ms to prevent the use of verbal encoding during memory arrays.An additional strength of Experiment 2, relative to Experiment 1, is the use of a more powerful statistical technique, multilevel modeling (MLM), to analyze the data. Multilevel modeling is appropriate in this case because our data are structured as responses within individuals, with duration as a within-person independent variable and age as a between-person independent variable. Typically the clustering of responses with individuals in repeated-measures design is addressed by averaging the responses but this approach discards potentially meaningful variability at the within-person level. Here, MLM allows us to analyze all responses for all durations and all participants in a single, powerful model.M = 13.41 years, SD = 0.25; 14 females), twenty-eight 16-year-olds , and 32 adults . All participants had normal or corrected-to-normal vision and were typically developing individuals with no neurological disorders, ADD/ADHD, learning disabilities, color blindness, or visual tracking problems. All adolescent participants were middle school and high school students, attending a variety of schools in Eugene, Oregon. All adult participants were University of Oregon undergraduates. One 13-year-old participant and one 16-year-old participant were not included in this final sample for performing below chance at higher set sizes, suggesting that these participants were not fully engaged in the task.The final sample included twenty-nine 13-year-olds  = 0.52, p = 0.60]. The average maternal education level corresponded to “completed some college classes” across age groups.Maternal education levels were compared as a proxy for SES and no differences were observed between groups  and the 16-year-olds .Similarly, for the K estimates excluding the set size 2 condition, duration of the memory array did not have a significant effect on the increase in VWM capacity in adults, t(86) = 1.71, p = 0.090. Unlike the analyses that included set size 2 condition, the difference in the rate of increase in VWM capacity between 13-year-olds and adults did not reach significance at the p < 0.05 level, but was very close to this alpha cut-off, t(86) = 1.97, p = 0.051. The rate of increase in capacity over presentation time did not differ between 16-year-olds and adults, t(86) = 1.31, p = 0.19.Also for the K estimates excluding the set size 2 condition which results in underestimation of capacity, a subsequent model was run, once again with heterogeneous error terms. To have a parsimonious model, as the rate of increase in VWM over presentation time did not differ significantly between the 16-year-olds and adults, age group was included only as a predictor of the capacity estimates at 1000 ms, but not as a predictor of the rate of decrease in capacity. This model revealed that even at 1000 ms, 16-year-olds performed worse than adults, t(58) = –2.20, p = 0.032, d = –0.41.To test whether 16-year-olds performed worse than adults even at the longest presentation condition, for the While Despite differentially benefiting from longer exposure to the memory array, both younger and older adolescents still performed worse than young adults. Longer exposure to the memory array diminished but did not eliminate the age differences in VWM capacity observed in Experiment 1. These findings suggest that the capacity differences observed between adolescents and adults in Experiment 1 were not driven solely by short presentation times and support the hypothesis that VWM capacity has a prolonged developmental trajectory.The present study investigated whether VWM capacity continues to develop through adolescence into adulthood. Overall, our results demonstrated that the capacity of VWM does not reach adult levels either in earlier or later years of adolescence. Regardless of whether the memory array was presented briefly or for longer durations, neither younger nor older adolescents displayed adult-like capacity estimates. Our findings are consistent with previous studies that demonstrated lower capacity estimates in early years of adolescence compared to adulthood . Here weOur results contradict the assertions that visual WM capacity reaches adult levels in infancy  or middlHowever, it is also likely that the discrepancy of findings between these infant studies and the other developmental studies of VWM capacity stems from paradigm differences. In studies that employed a variation of the change detection task  with chiSeveral studies reported developmental changes for verbal and spatial working memory span tasks throughout adolescence . FurtherAlthough our study provides evidence for age related differences in VWM capacity between adolescents and adults, the mechanisms underlying such differences require further investigation. Adolescence is a pivotal period for brain development during which substantial changes are observed . PreviouPotentially, the age related differences in VWM capacity estimates may stem from disparities in attention skills rather than genuine differences in the number of slots available in VWM. Attentional control has been postulated as a critical component of working memory . In suppHowever, the mechanisms responsible for the poorer performance of adolescents and low capacity adults may also be distinct from each other. For instance, in a study comparing older adults to younger adults, older adults were not simply like low capacity young adults, despite performing worse than younger adults on average . SimilarAlternatively, the observed differences in performance may stem from age related disparities in the number of slots available in VWM. A recent study with children investigated whether such disparities in available slots account for differences in performance between children and adults . It was In addition to differing in VWM capacity estimates, adolescents may differ from adults in the resolution of VWM representations. It has been demonstrated that the number of items held in mind for immediate access and the resolution of these representations are distinct aspects of VWM . TherefoIt is important to note that in both studies we compared adolescents to young adults, who were on average 20 years of age. Although it has been argued that VWM performance peaks at age 20 , we cannAlthough much remains to be investigated, our study provides evidence for a protracted developmental profile of VWM capacity. As a late developing system that does not appear to reach adult levels even in late adolescence, VWM capacity bears the potential to be a rather plastic system in development, malleable to the effects of the environment. Studies on neuroplasticity across development have repeatedly demonstrated that plastic systems can both be compromised and enhanced depending on experience . TherefoThe 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.