Codispoti Maurizio, Ferrari Vera, Bradley Margaret M
Department of Psychology, University of Bologna, Bologna, Italy.
Brain Res. 2006 Jan 12;1068(1):213-20. doi: 10.1016/j.brainres.2005.11.009. Epub 2006 Jan 5.
Emotionally arousing pictures elicit larger late positive potentials (LPPs) than neutral pictures during passive viewing. Moreover, these cortical responses do not rely on voluntary evaluation of the hedonic content and are relatively unaffected by task demands. In this study, we examined modulation of the late positive potential as it varies with stimulus repetition. Three pictures (pleasant, neutral, unpleasant) were presented up to 60 times each. Although the amplitude of the late positive potential during picture viewing declined with stimulus repetition, affective modulation remained intact. On the other hand, autonomic responses (skin conductance and heart rate change) habituated rapidly with stimulus repetition. These findings suggest that while stimulus detection and categorization, reflected in the LPP, is mandatory, autonomic modulation reflects initial orienting responses that habituate rapidly.
在被动观看过程中，引发情绪的图片比中性图片诱发更大的晚期正电位（LPPs）。此外，这些皮层反应不依赖于对享乐内容的自愿评估，并且相对不受任务要求的影响。在本研究中，我们考察了晚期正电位随刺激重复而变化的调节情况。呈现了三张图片（愉悦、中性、不悦），每张图片最多呈现60次。尽管在图片观看期间晚期正电位的幅度随刺激重复而下降，但情感调节仍然完好。另一方面，自主反应（皮肤电导率和心率变化）随刺激重复而迅速习惯化。这些发现表明，虽然LPP中反映的刺激检测和分类是强制性的，但自主调节反映的是迅速习惯化的初始定向反应。
