Section of Neurobiology of Psychosis, Department of Psychosis Studies, Institute of Psychiatry, King's College London, London SE5 8AF, United Kingdom.
J Neurosci. 2011 Oct 5;31(40):14378-85. doi: 10.1523/JNEUROSCI.2400-11.2011.
The perception of facial affect engages a distributed cortical network. We used functional magnetic resonance imaging and dynamic causal modeling to characterize effective connectivity during explicit (conscious) categorization of affective stimuli in the human brain. Specifically, we examined the modulation of connectivity from posterior regions of the face-processing network to the lateral ventral prefrontal cortex (VPFC) during affective categorization and we tested for a potential role of the amygdala (AMG) in mediating this modulation. We found that explicit processing of facial affect led to prominent modulation (increase) in the effective connectivity from the inferior occipital gyrus (IOG) to the VPFC, while there was less evidence for modulation of the afferent connections from fusiform gyrus and AMG to VPFC. More specifically, the forward connection from IOG to the VPFC exhibited a selective increase under anger (as opposed to fear or sadness). Furthermore, Bayesian model comparison suggested that the modulation of afferent connections to the VPFC was mediated directly by facial affect, as opposed to an indirect modulation mediated by the AMG. Our results thus suggest that affective information is conveyed to the VPFC along multiple parallel pathways and that AMG activity is not sufficient to account for the gating of information transfer to the VPFC during explicit emotional processing.
面部情感感知涉及一个分布式皮质网络。我们使用功能磁共振成像和动态因果建模来描述人类大脑中情感刺激的显式（有意识）分类过程中的有效连接。具体来说，我们研究了在进行情感分类时，面部处理网络的后区到外侧腹侧前额叶皮层（VPFC）的连接的调制，并测试了杏仁核（AMG）在介导这种调制中的潜在作用。我们发现，对面部情感的显式处理导致了从下枕叶（IOG）到 VPFC 的有效连接的明显调制（增加），而来自梭状回和 AMG 到 VPFC 的传入连接的调制证据较少。更具体地说，在愤怒（相对于恐惧或悲伤）时，IOG 到 VPFC 的前向连接表现出选择性增加。此外，贝叶斯模型比较表明，VPFC 的传入连接的调制是由面部情感直接介导的，而不是由 AMG 介导的间接调制。因此，我们的结果表明，情感信息沿着多条平行途径传递到 VPFC，并且 AMG 活动不足以解释在显式情感处理过程中信息传递到 VPFC 的门控。
