N400 and LPP in spontaneous trait inferences

Area of Science:

• Cognitive Neuroscience
• Social Psychology
• Psychophysiology

Background:

• Previous event-related potential (ERP) research on spontaneous trait inferences often noted late positive potential (LPP) increases after social expectancy violations.
• However, prior studies typically did not report N400 modulation in response to such inconsistencies.

Purpose of the Study:

• To investigate the neural underpinnings of spontaneous trait inferences when behavioral information is inconsistent with prior trait implications.
• To examine event-related potential (ERP) modulations, specifically N400 and LPP, during the processing of social expectancy violations.

Main Methods:

• Participants read scenarios implying traits, followed by a final sentence that was either consistent or inconsistent with the implied trait.
• Event-related potentials (ERPs) were recorded, and analyses included temporal principal component analysis (PCA) and standardized low-resolution electromagnetic tomography (sLORETA).

Main Results:

• Significantly increased LPP amplitudes were observed at frontal sites following inconsistent behaviors, consistent with prior research.
• Unlike previous findings, this study also detected increased N400 amplitudes at centro-parietal sites in response to trait-inconsistent behaviors.

Conclusions:

• The findings suggest that increased N400 reflects cognitive challenges in understanding unanticipated behaviors.
• The concurrent LPP effect may indicate evaluative incongruence or emotional response to the unexpected social information.
• Methodological variations in stimulus presentation might explain discrepancies with prior ERP research on social cognition.