Tamietto Marco, Cauda Franco, Celeghin Alessia, Diano Matteo, Costa Tommaso, Cossa Federico M, Sacco Katiuscia, Duca Sergio, Geminiani Giuliano C, de Gelder Beatrice
Department of Psychology, University of Torino, Italy; Cognitive and Affective Neuroscience Laboratory, CoRPS - Center of Research on Psychology in Somatic Diseases - Tilburg University, The Netherlands.
Department of Psychology, University of Torino, Italy; GCS-fMRI, Koelliker Hospital, Torino, Italy.
Cortex. 2015 Jan;62:56-72. doi: 10.1016/j.cortex.2014.10.009. Epub 2014 Nov 1.
The interplay between the neural mechanisms of visual awareness and those involved in emotion processing and the mapping of related somatic changes remains unclear. To address this issue we studied one patient with visual extinction following right parietal damage, in a combined behavioral, psychophysiological and neuroimaging experiment. Patient M.P. was presented with neutral and fearful bodily expressions, either unilaterally in the left (LVF) or right visual field (RVF), or in both visual fields simultaneously. Fearful expressions presented in the left visual field simultaneously with neutral bodies in the RVF were detected more often than left-side neutral bodies. Signal detection analysis showed that the preferential access of fearful bodies to visual awareness is related to higher perceptual sensitivity for these stimuli during attentional competition. Pupil dilation, which indexes autonomic arousal, increased for fearful more than for neutral bodies. Moreover, dilation for extinguished fearful bodies was bigger than for consciously perceived fearful bodies. This decoupling between (increased) arousal and (lack of) conscious visual experience argues against a direct relationship between visual awareness of emotional signals and peripheral changes. Neuroimaging results showed that fearful bodies activated the left amygdala and extrastriate cortex when consciously perceived as well as when extinguished. Critically, however, conscious perception of fearful bodies was uniquely associated with activity in the anterior insula, somatosensory, motor and premotor cortex (PMC), and the cerebellum. This suggests that the integration between peripheral arousal and the moment-to-moment mapping at the central neural level of these bodily changes is critical for the conscious visual experience of emotional signals.
视觉意识的神经机制与情绪加工及相关躯体变化映射之间的相互作用仍不清楚。为解决这一问题,我们在一项行为、心理生理学和神经影像学相结合的实验中,对一名右侧顶叶损伤后出现视觉消退的患者进行了研究。向患者M.P.呈现中性和恐惧的身体表情,这些表情或者单侧出现在左视野(LVF)或右视野(RVF),或者同时出现在两个视野中。当右侧视野为中性身体时,同时出现在左视野的恐惧表情比左侧中性身体被检测到的频率更高。信号检测分析表明,在注意力竞争期间,恐惧身体对视觉意识的优先获取与对这些刺激更高的感知敏感性有关。作为自主唤醒指标的瞳孔扩张,对恐惧表情的反应比对中性身体的反应更大。此外,对消退的恐惧身体的扩张比对有意识感知到的恐惧身体的扩张更大。这种(增加的)唤醒与(缺乏的)有意识视觉体验之间的脱钩,反对了情绪信号的视觉意识与外周变化之间的直接关系。神经影像学结果表明,恐惧身体在被有意识感知以及被消退时,都会激活左侧杏仁核和纹外皮层。然而,至关重要的是,对恐惧身体的有意识感知与前脑岛、体感、运动和运动前皮层(PMC)以及小脑的活动独特相关。这表明外周唤醒与这些身体变化在中枢神经水平上的即时映射之间的整合,对于情绪信号的有意识视觉体验至关重要。