Carretié L, Iglesias J, García T, Ballesteros M
Departamento de Psicología Biológica y de la Salud, Universidad Autónoma de Madrid, Spain.
Electroencephalogr Clin Neurophysiol. 1997 Aug;103(2):298-303. doi: 10.1016/s0013-4694(96)96565-7.
Two components of the ERPs elicited by emotional visual stimuli, N300 and P300, were investigated. The emotional charge is explained through two dimensions: arousal (relaxing (R) or activating (A)) and valence (attractive (+) or repulsive (-)). Stimuli were slides of nudes (A+), human remains (A-), landscapes (R), and buildings (neutral (N)). The peculiar structure of the stimuli, along with a distracting task which allowed us to disguise the real aim of the experiment, helped to avoid a sort of 'relevance-for-task effect', mainly related to cognitive processes, which could explain P300 reactions in response to emotional visual stimuli found in several experiments. The ERPs were recorded from 32 subjects at F3, Fz, F4, C3, Cz, C4, P3, Pz and P4. In contrast to previous studies, P300 did not show greater amplitudes in response to emotional stimuli than to N. N300 showed greater amplitudes in response to A+ at parietal sites, the greatest differences being those with respect to A-. No inter-hemispheric differences were found. N300 confirms its usefulness as a variable for studying emotional reactions to visual stimuli.
研究了由情感视觉刺激引发的事件相关电位（ERP）的两个成分，即N300和P300。情感负荷通过两个维度来解释：唤醒度（放松（R）或激活（A））和效价（吸引人（+）或排斥人（-））。刺激物是裸体幻灯片（A+）、人体遗骸幻灯片（A-）、风景幻灯片（R）和建筑幻灯片（中性（N））。刺激物的特殊结构，以及一项分散注意力的任务，使我们能够掩盖实验的真正目的，这有助于避免一种主要与认知过程相关的“任务相关性效应”，这种效应可能解释了在几个实验中发现的对情感视觉刺激的P300反应。从32名受试者的F3、Fz、F4、C3、Cz、C4、P3、Pz和P4部位记录ERP。与之前的研究不同，P300对情感刺激的反应幅度并不比对中性刺激的反应幅度更大。N300在顶叶部位对A+刺激的反应幅度更大，与A-刺激相比差异最大。未发现半球间差异。N300证实了其作为研究对视觉刺激的情感反应的一个变量的有用性。
