第33回日本神経科学大会

会期:2010.9.2-4(発表日9月3日)
会場: 神戸コンベンションセンター

Inagaki, M., Fujita, I. (2010)Time course of neuronal selectivity for facial expression: comparison between the temporal visual cortex and the amygdala
稲垣未来男、藤田一郎「顔反応性細胞の表情に対する選択性の時間経過: 側頭葉視覚皮質と扁桃体の比較」

妙録O2-8-2-4
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Facial expression plays an important role in social communication in humans and non-human primates. Neurons showing selectivity for facial expression of visually presented face images have been found in the temporal visual cortex and the amygdala. Although the selectivity for facial expression has been previously assessed, the origin of the selectivity has remained unclear. Because of reciprocal anatomical connections, the activities of temporal cortex neurons can influence those of amygdala neurons and vice versa. Both areas therefore could be the initial source of facial expression selectivity. Here, we compared the time course of the neuronal selectivity for facial expression between the temporal visual cortex and the amygdala. We used two Japanese monkeys (Macaca fuscata) and recorded extracellular neuronal activities while the monkeys were engaged in a simple fixation task. We presented three facial expressions (open-mouth, pout-lips, and neutral) by three different monkeys for a total of nine images. We measured the responses with a sliding 50 ms time window and repeatedly analyzed selectivity for facial expression along the time axis (two-way ANOVA; factors, facial expression, face identity; p < 0.05, Bonferroni correction). The percentage of facial-expression selective neurons in the temporal visual cortex first exceeded chance in the time window 57 to 106 ms, whereas that of the amygdala first exceeded chance at 102 to 151 ms. The population latency of the selectivity in the temporal visual cortex was shorter than that of the amygdala by 45 ms. From these results, we suggest that facial-expression selective responses are initiated in the temporal visual cortex and then the information spreads into the amygdala.