Sex differences in interhemispheric communication during face identity encoding: evidence from ERPs

Area of Science:

• Neuroscience
• Cognitive Psychology
• Human Brain Imaging

Background:

• Hemispheric lateralization, the specialization of brain functions in one hemisphere, is well-documented.
• Sex-related differences in brain structure and function are increasingly recognized, but their impact on face processing remains an active area of research.

Purpose of the Study:

• To investigate sex-related differences in hemispheric lateralization and interhemispheric transmission times (IHTTs) during face identity encoding.
• To examine these differences at the level of early visual event-related potential (ERP) components, specifically P1 and N170.

Main Methods:

• Utilized a divided visual-field paradigm to present faces to either the left or right visual field.
• Recorded event-related potentials (ERPs), focusing on P1 and N170 components, to analyze brain activity.
• Measured interhemispheric transmission times (IHTTs) derived from ERP latencies.

Main Results:

• No significant sex-related differences or lateralization effects were observed for the P1 component.
• The N170 component showed sex-specific patterns: right hemisphere (RH) dominance in men and more bilateral activity in women.
• N170 latencies and derived IHTTs indicated an RH advantage in men and a left hemisphere (LH) advantage in women.

Conclusions:

• Face identity encoding reveals distinct patterns of hemispheric lateralization between men and women, starting at the N170 component.
• These findings suggest functional, rather than structural, differences underlying sex-related hemispheric asymmetries in face processing.
• The results generalize previous findings, highlighting sex differences in interhemispheric communication efficiency, particularly in the male brain.