er to see that a scanned image, similarly to a photographic image, maintains an indirect and synthetic relationship with the “real” that necessitates the incorporation and the preliminary solidification of numerous theoretical and technical elements. As regards the production/visualization of differences as a function of age and sex, one can observe that binary categorization by age and by sex is present at all stages of the experiment : adult men and women are represented in the stimulus photographs and young girls and young boys are tested. However, it is only through the translation of the results of the experiment into scanned images that the differences linked to age and sex become scientifically relevant in connection with the management of emotional information. It is the chain of recordings and transcriptions (Latour 2006) of the notions of fear, sex and age that allows their reorganization and reinterpretation in the course of the experimental process, retaining all the while traces of preceding stages in the process of constructing knowledge about cerebral adolescence. For example, the use of male and female models in the production of the photographs of facial affect makes no attempt to account for any difference between men and women in connection with the emotions, but on the contrary, aims to guarantee the universality of those images in the reflection of a reality thought to be universal, i.e. the division of the human genus between males and females. Whereas the distribution between as many girls as boys in the sample of adolescents tested is constitutive of the experimental protocol whose purpose is to detect a differentiation in cerebral activation between teenage girls and boys in an emotional situation. The young guinea pigs are expected to be representative of the behavioral differences demonstrated by epidemiological studies based on classifications of age and sex.
In other words, the scanned image contains and communicates not only visual evidence of a cerebral activation triggered by a stimulus which is considered a valid way of measuring the management of emotional information, but also the entire concept of adolescence that has emerged from developmental psychology and epidemiology and to which the neuroscience researchers themselves refer. In defining adolescence primarily by so-called risk behaviors, for which the difference between boys and girls is constitutive of public health policy interests concerning adolescence, the emotional adolescent brain is in fact gendered. Thus one observes that the sexing of the emotional adolescent brain proceeds less from the binary categorization by sex of the actors represented in the stimulus photographs and of the test subjects themselves than from the incorporation by the scanned image of discourses related to gender differences — here, the differential involvement in risk behaviors — which motivate the research.
Developing a set of photographs of facial affect, like mapping the treatment of emotional information among adolescents with fMRI, could be seen as the result of a practical and heuristic attempt to capture in sequential images the shifting and intangible states that are the emotions. In fact, the study of emotions in the laboratory requires that they be made controllable, both because of the practicalities of the experimental protocol — e.g. the limited space in a scanner — and in order to be able to make them compatible with the logic of recording and measuring inherent in scientific activity. In this context, photographs representing emotions, like fMRI-generated images of the brain reacting to those photographs, appear to be the preferred mechanisms for registering and reproducing emotions because of the undisputed relationship that would seem to exist between the photographic or the scanned image and the truth (Beaulieu 2002, Dumit 2004). That is to say, these images are considered to bear objective information that is independent of the context of their production and of the conditions that allow their reception. As I have shown in this ac