关键词: 负性背景, 条件性关联学习, 条件性消退, 性别差异, 事件相关电位

Abstract:

Gender differences in response to conditioned acquisition and extinction were observed in previous studies. The possible reasons for these differences might be the different strategies and modulations applied on males and females. Event related potentials have been used to quantify the conditioned acquisition and conditioned extinction of late recently. In this study, the event related potentials associated with sex differences in the acquisition and extinction of conditioned negative context were measured. Fifteen man with age and weight matched women were enrolled in this study. The present research consisted of three experimental phases of memory: habituation phase, acquisition phase and extinction phase. In the habituation phase, there are three negative context pictures as conditioned stimuli (CS). Participants were asked to attractively view the three pictures. In the acquisition phase, there was a neutral tone (as the unconditioned stimuli, US) signal appeared at the end of the presentations of negative context pictures. Participants were instructed to press a button as soon as possible when the tone emerged. Then they would go to the next trail. In extinction phase, the neutral tones were extinguished. Participants were instructed to press a button as soon as possible when hearing the tone and not press any button when hearing nothing. ERP analyses showed that shorter P2 latency and more N2 modulate in men than in women, whereas more P3 modulate in women than in men in habituation phase. The results suggested that men might probe the CS-US conditional acquisition faster than women. It indicated that women might be more difficult to get rid of the influence of negative context than men. In extinction phase, results showed attenuated P2 amplitude and larger P3/LPP amplitude in women than in men. The results showed that women might detect the extinction process slower and allocate more attention resources in the extinction process than men. Combined with the results of the two stages, the differences between men and women in the conditioned acquisition and extinction processes may be underlaid very complicated cognitive processes. The findings in this study extends our knowledge from previous behavioral studies in this field and shed light on the neural associates of the gender differences in the cognitive and emotional processes.

Key words: negative context, conditioned acquisition, conditioned extinction, gender differences, event-related potentials