Is there less to social anxiety than meets the eye? Emotion experience,expression, and bodily responding

Emotions are widely held to involve changes in experiential, behavioural, and physiological systems. It is not clear, however, just how tightly coupled these changes are during emotional responding. To examine this issue, we induced social anxiety in 47 high trait social anxiety (HTSA) and 50 low trait social anxiety (LTSA) participants using an impromptu speech paradigm. We assessed anxiety experience, behaviour, perceived physiological activation, and actual physiological activation. HTSA participants felt more anxious, perceived greater physiological activation, and exhibited more anxiety behaviour than LTSA participants. Unexpectedly, the two groups did not differ in objectively measured physiological responding. Internal analyses indicated that for both HTSA and LTSA participants, anxiety experience was associated with perceived physiological activation, but not with actual physiological responding. These results suggest that anxiety experience and perceived physiological activation may be less tightly coupled with actual physiological responses than is typically thought.     

The neonate brain's sensitivity to repetition-based structure: Specific to speech?

Newborns are able to extract and learn repetition-based regularities from the speech input, that is, they show greater brain activation in the bilateral temporal and left inferior frontal regions to trisyllabic pseudowords of the form AAB (e.g., “babamu”) than to random ABC sequences (e.g., “bamuge”). Whether this ability is specific to speech or also applies to other auditory stimuli remains unexplored. To investigate this, we tested whether newborns are sensitive to regularities in musical tones. Neonates listened to AAB and ABC tones sequences, while their brain activity was recorded using functional Near-Infrared Spectroscopy (fNIRS). The paradigm, the frequency of occurrence and the distribution of the tones were identical to those of the syllables used in previous studies with speech. We observed a greater inverted (negative) hemodynamic response to AAB than to ABC sequences in the bilateral temporal and fronto-parietal areas. This inverted response was caused by a decrease in response amplitude, attributed to habituation, over the course of the experiment in the left fronto-temporal region for the ABC condition and in the right fronto-temporal region for both conditions. These findings show that newborns’ ability to discriminate AAB from ABC sequences is not specific to speech. However, the neural response to musical tones and spoken language is markedly different. Tones gave rise to habituation, whereas speech was shown to trigger increasing responses over the time course of the study. Relatedly, the repetition regularity gave rise to an inverted hemodynamic response when carried by tones, while it was canonical for speech. Thus, newborns’ ability to detect repetition is not speech-specific, but it engages distinct brain mechanisms for speech and music.

Research Highlights

• The ability of newborns’ to detect repetition-based regularities is not specific to speech, but also extends to other auditory modalities.
• The brain mechanisms underlying speech and music processing are markedly different.