Enter feelings: somatosensory responses following early stages of visual induction of emotion.

In a MEG experiment, we imaged the early dynamics of the human cerebral cortex during the induction of emotion by visual stimuli. We tested the hypothesis that early cortical responses would correlate with the emotional competence of visual stimuli and subsequent subjective ratings of feeling in a set of specific target regions important for somatosensory, attentional, and motivational functions, just after initial visual and appraisal related cortical responses to picture presentation. Relative to the neutral condition, cortical responses, during the 350-500 ms phase of the MEG evoked response, were stronger for both pleasant and unpleasant stimuli in the orbitofrontal cortex, ventromedial prefrontal cortex, anterior cingulate and somatosensory cortices. These responses, which correlated with subjective ratings of arousal, emerged after an initial spreading of cortical activity from early visual cortex (70-200 ms) to the ventral visual stream, temporopolar and orbitofrontal regions (200-350 ms), higher for emotionally competent stimuli than for neutral in the 200-350 ms window, in a manner compatible with an appraisal function. Heart beats occurring during the first 500 ms post stimulus showed longer intervals for unpleasant than for neutral stimuli relative to the preceding beat. The results support the hypothesis of a sequence of processing regarding the emergence of feelings and suggest that, even in the early phase of feeling induction, actual body responses to the inducing stimuli could be represented in the brain.