Multiple synergistic effects of emotion and memory on proactive processes leading to scene recognition

Visual scene recognition is a proactive process through which contextual cues and top-down expectations facilitate the extraction of invariant features. Whether the emotional content of the scenes exerts a reliable influence on these processes or not, however, remains an open question. Here, topographic ERP mapping analysis and a distributed source localization method were used to characterize the electrophysiological correlates of proactive processes leading to scene recognition, as well as the potential modulation of these processes by memory and emotion. On each trial, the content of a complex neutral or emotional scene was progressively revealed, and participants were asked to decide whether this scene had previously been encountered or not (delayed match-to-sample task). Behavioral results showed earlier recognition for old compared to new scenes, as well as delayed recognition for emotional vs. neutral scenes. Electrophysiological results revealed that, ~400 ms following stimulus onset, activity in ventral object-selective regions increased linearly as a function of accumulation of perceptual evidence prior to recognition of old scenes. The emotional content of the scenes had an early influence in these areas. By comparison, at the same latency, the processing of new scenes was mostly achieved by dorsal and medial frontal brain areas, including the anterior cingulate cortex and the insula. In the latter region, emotion biased recognition at later stages, likely corresponding to decision making processes. These findings suggest that emotion can operate at distinct and multiple levels during proactive processes leading to scene recognition, depending on the extent of prior encounter with these scenes.