认知与情绪过程的脑诱发电位研究——情绪的适应性假说

本研究观测了30名女性被试在月经周期中的不同激素时相对图像刺激的情绪价值的主观评估和脑诱发电位反应。调节刺激的情绪价值的五类幻灯片分别为普通人像、婴儿像、皮肤病人像、男模特儿像和女模特儿像。实验发现只有脑诱发电位的P3成份随刺激的情绪价值和激素的时相而变化。被评为喜爱与不喜爱的图像(婴儿像和皮肤病人像)所诱发的P3波在幅度上均明显高于中性图像(普通人像)所致的P3反应。在高孕激素时相,对婴儿像和男模特儿像的P3反应高于在低孕激素时相对同类刺激的P3反应。高孕激素时相还伴有对各类图像性感程度评估值的降低。对各类图像喜爱程度的评估则随雌激素水平的上升而增高。上述实验结果表明,P3波敏感于刺激的情绪价值并反映了认知与情绪过程中受生理状态调节的适应性变化。

EVOKED BRAIN POTENTIAL STUDIES OF EMOTIONAL AND COGNITIVE PROCESSES: EMOTIONAL ADAPTATION HYPOTHESIS

The current study examined subjective ratings and evoked brain potentialsto the emotional value of picture stimuli collected from 30 female subjects indifferent hormonal phases of their menstrual cycles. The emotional value of thestimuli was manipulated by five slide categories, the content were ordinarypeople, babies, dermatological cases, male models and female models. It wasfound that only the P3 component of evoked brain potentials varied with theemotional value of the stimuli and hormonal phases. The picture categoriesthat were rated as pleasant and unpleasant (babies and dermatological cases)elicited significantly larger P3 amplitude than the neutral category (ordinarypeople). The P3 responses to babies and male models in high progesterone ph-ase were larger than those in low progesterone phase. High progesterone phase wasalso associated with a decrease in the rating scores on eroticism of all slidecategories. An increase in the pleasantness of all categories was evident whenestrogen levels were high. The above experimental results suggest that P3component is sensitive to the emotional value of a stimulus and reflects theadaptive changes in cognitive and emotional processes regulated by physiologi-cal status.