Hemodynamic and electrocortical reactivity to specific scene contents in emotional perception.

Emotional scene perception is characterized by enhanced neural activity across broad regions of visual cortex, the frontoparietal network, and anterior corticolimbic structures. In human fMRI and electrocortical experiments, activation enhancement is strongly related to self-reported emotional arousal evoked by scene stimuli. However, an additional bias in reaction to pleasant scenes has been reported in a subset of emotion-enhanced brain regions. Human fMRI and primate electrophysiological studies show biased frontoparietal network activity in response to rewarding cues. In addition, activation in lateral occipital regions may show a bias in pleasant scene perception, as shown in fMRI and in the early posterior negativity (EPN) ERP component. To define this potential pleasure bias, we presented a balanced set of naturalistic scenes to participants during separate fMRI and ERP recording sessions. Consistent with past work, the amplitude of the slow-wave late positive potential (LPP), as well as hemodynamic activity in fusiform gyrus and amygdala, showed equivalent enhancement across highly arousing pleasant and unpleasant, relative to neutral scenes. In addition to this emotional enhancement, the EPN component, as well as hemodynamic activity in lateral occipital cortex and frontoparietal network, showed greater reactivity during highly arousing pleasant relative to unpleasant scenes, consistent with a pleasure bias. The interpretation of this pattern of reactivity is discussed with respect to selective and evolved attention mechanisms.