Discrepancy between self-report and neurophysiological markers of socio-affective responses in lonely individuals

Theoretical models suggest that loneliness may be linked to abnormal social information processing and reduced emotion regulation capacity; yet these effects have mostly been investigated using self-report methods. Therefore, the current preregistered study examined whether loneliness is associated with objective and subjective markers of bottom-up emotional reactivity and cognitive reappraisal efficiency in a cohort of 150 young adults (18-35 years old) recruited to reflect the distribution of loneliness scores in the Polish population. Participants completed an emotion processing and regulation task with both social and nonsocial stimuli while their electroencephalography activity was recorded. Contrary to the hypotheses, when faced with socio-affective stimuli, lonelier individuals did not exhibit abnormal markers of early sensory processing, late sustained processing, or decreased efficiency in reappraisal use, as indicated by event-related potential markers. Only a weak association between loneliness and an increased P300 response to negative vs. neutral social stimuli was found. This pattern of findings did not align with subjective arousal reports, which suggested a decreased response to negative social stimuli and reduced cognitive reappraisal efficiency in lonelier participants. These results suggest that loneliness is linked to disruptions in emotional self-awareness rather than an abnormal response to socio-affective stimuli.