No abstract

The ability to infer the authenticity of other’s emotional expressions is a social cognitive process taking place in all human interactions. Although the neurocognitive correlates of authenticity recognition have been probed, its potential recruitment of the peripheral autonomic nervous system is not known. In this work, we asked participants to rate the authenticity of authentic and acted laughs and cries, while simultaneously recording their pupil size, taken as proxy of cognitive effort and arousal. We report, for the first time, that acted laughs elicited higher pupil dilation than authentic ones and, reversely, authentic cries elicited higher pupil dilation than acted ones. We tentatively suggest the lack of authenticity in others’ laughs elicits increased pupil dilation through demanding higher cognitive effort; and that, reversely, authenticity in cries increases pupil dilation, through eliciting higher emotional arousal. We also show authentic vocalizations and laughs (i.e. main effects of authenticity and emotion) to be perceived as more authentic, arousing and contagious than acted vocalizations and cries, respectively. In conclusion, we show new evidence that the recognition of emotional authenticity can be manifested at the level of the autonomic nervous system in humans. Notwithstanding, given its novelty, further independent research is warranted to ascertain its psychological meaning.

Cross-cultural studies of emotion recognition in nonverbal vocalizations not only support the universality hypothesis for its innate features, but also an in-group advantage for culture-dependent features. Nevertheless, in such studies, differences in socio-economic-educational status have not always been accounted for, with idiomatic translation of emotional concepts being a limitation, and the underlying psychophysiological mechanisms still un-researched. We set out to investigate whether native residents from Guinea-Bissau (West African culture) and Portugal (Western European culture)—matched for socio-economic-educational status, sex and language—varied in behavioural and autonomic system response during emotion recognition of nonverbal vocalizations from Portuguese individuals. Overall, Guinea–Bissauans (as out-group) responded significantly less accurately (corrected p < .05), slower, and showed a trend for higher concomitant skin conductance, compared to Portuguese (as in-group)—findings which may indicate a higher cognitive effort stemming from higher difficulty in discerning emotions from another culture. Specifically, accuracy differences were particularly found for pleasure, amusement, and anger, rather than for sadness, relief or fear. Nevertheless, both cultures recognized all emotions above-chance level. The perceived authenticity, measured for the first time in nonverbal cross-cultural research, in the same vocalizations, retrieved no difference between cultures in accuracy, but still a slower response from the out-group. Lastly, we provide—to our knowledge—a first account of how skin conductance response varies between nonverbally vocalized emotions, with significant differences (p < .05). In sum, we provide behavioural and psychophysiological data, demographically and language-matched, that supports cultural and emotion effects on vocal emotion recognition and perceived authenticity, as well as the universality hypothesis.

Background: Human social behavior is modulated by oxytocin (OT). Intranasal administration of OT (IN-OT) is a noninvasive route shown to elicit changes in the autonomic nervous system (ANS) activity; however, IN-OT’s effect on the temporal profile of ANS activity at rest is yet to be described. Aims: We aimed to describe the temporal profile of IN-OT at six 10-min time windows from 15- to 100-min post-administration in 20 male participants at rest while continuously recording their pupillary in an eyes-open condition and cardiac activity in eyes-open and eyes-closed conditions. Methods: We used a double-blind, placebo-controlled, within-subjects design study where we extracted two proxies of parasympathetic nervous system (PNS) activity: high-frequency heart rate variability (HF-HRV) and pupillary unrest index (PUI); and a proxy of sympathetic nervous system activity: sample entropy of the pupillary unrest. Results: In the eyes-open condition, we found an effect of IN-OT on the proxies of PNS activity: decreased PUI in the three-time windows post-administration spanning 65–100 min, and as an exploratory finding, an increased HF-HRV in the 80–85 min time window. Conclusions: We suggest there is a role of OT in PNS regulation that may be consistent with OT’s currently theorized role in the facilitation of alertness and approach behavior.