Neurophysiological Basis of the Cognitive Gender Differences in Adulthood in Humans. Evidence from Event-related Brain Potentials

Abstract

Gender can affect nervous system functioning at multiple levels – from genetics to behaviour. In the present review, effects of gender on neurophysiologic mechanisms of mental rotation, efficiency of language processing, emotions and sensory processes were studied in adults by exploring event-related brain potentials (ERPs). Since these processes were best recognized as gender-dependent at the behavioural level, it was aimed to verify the presence of gender effects on the respective ERP correlates at the neurophysiologic level. Articles from the PubMed database were selected, with a publication year until 2020. The review additionally includes studies that were cited in the selected articles. Thus, forty-six articles published between 1982 and 2020 were included. The reviewed data of healthy humans demonstrate that gender affects the early (related to perception and identification) and the late stages of processing (related to actual cognitive processes) of ERPs elicited during the three cognitive categories (mental rotation, language, and emotions). Mental rotation process in males demonstrates smaller amplitudes and shorter latencies of ERP components. It is concluded that men perform mental rotation more efficiently than females because they not only apply a different processing strategy (implied by distinct topography patterns), but they also benefit from faster processing mechanisms. During language processing, gender differences are expressed in increased amplitudes, shortened latencies, and different scalp topographies of language-related ERPs in females compared to males. ERPs confirm that the two genders employ different processing strategies and provide new evidence that females’ advantages can be associated with the fact that women are involved in a more extensive, more in-depth semantic processing and have a more automatized language processing. Gender differences in the emotion-related processes are mainly expressed as increased ERP amplitudes in females compared to males for both the early and late ERP components. ERP results reveal that women are more sensitive to emotionally salient stimuli, especially to unpleasant negative ones, and that this sensitivity extends beyond early emotional reactivity to a later emotional and emotion-regulation processes. However, studies exploring the neurophysiological level of the mental rotation process, language, and emotional processing in men and women are still scarce and inconsistent and thus further extensive research is required. The present review provides important hints that many of the established gender effects on specific processes (mental rotation, language and emotion regulation) may originate from fundamental and material-unspecific effects of gender on sensory processing mechanisms, which also merits additional clarification.