A growing body of research now documents a specific pattern of brain activation during emotional tasks in patients with social phobia. Furthermore, recent studies indicate that non-clinical participants show a similar pattern of responses. Clinical and physiological data from literature highlight that social anxiety is associated with difficulties in emotional managing. However, much less is known about the part of alexithymia in social phobia, as far as clinical and infra-clinical (high shyness) approaches are concerned.

Four hundred undergraduate university students were screened with an anxiety and social phobia questionnaire. Forty participants, with low and high levels of social phobia, were then included according to a dimensional approach. Each participant underwent a comprehensive psychiatric evaluation that included a structured clinical interview for current and past psychiatric disorders and psychometric scales, including the Liebowitz Social Anxiety Scale (LSAS) and the Toronto Alexithymia Scale (TAS-20). Participants were asked to make gender discrimination choices when viewing faces that showed happiness, fear, anger, sadness, neutral expressions or distractors while in a 3 Tesla fMRI scanner.

As expected, social phobia trait was correlated with TAS-20 scores, and specifically in “difficulties identifying feelings”. Brain activations showed an evolutionary pattern response in correlation with social phobia and alexithymia concerning limbic regions (amygdala and insula). Social phobia trait seems to be particularly receptive to anger faces.

Our findings support the hypothesis that alexithymia play a major role in social anxiety disorder. Identifying feelings could explain alexithymic functioning in social phobia, clinically and physiologically.