Common circuit or paradigm shift? The functional brain in emotional scene perception and emotional imagery

Abstract

Meta-analytic and experimental studies investigating the neural basis of emotion often compare functional activation in different emotional induction contexts, assessing evidence for a "core affect" or "salience" network. Meta-analyses necessarily aggregate effects across diverse paradigms and different samples, which ignore potential neural differences specific to the method of affect induction. Data from repeated measures designs are few, reporting contradictory results with a small N. In the current study, functional brain activity is assessed in a large (N = 61) group of healthy participants during two common emotion inductions-scene perception and narrative imagery-to evaluate cross-paradigm consistency. Results indicate that limbic and paralimbic regions, together with visual and parietal cortex, are reliably engaged during emotional scene perception. For emotional imagery, in contrast, enhanced functional activity is found in several cerebellar regions, hippocampus, caudate, and dorsomedial prefrontal cortex, consistent with the conception that imagery is an action disposition. Taken together, the data suggest that a common emotion network is not engaged across paradigms, but that the specific neural regions activated during emotional processing can vary significantly with the context of the emotional induction.

Keywords: emotion; fMRI; narrative imagery; scene perception.

Figure 1.

Middle Panel: Emotional perception and imagery. Regions uniquely involved in emotional visual perception (red) and emotional imagery (aqua), ordered from activation in more posterior (y = 74) to more anterior regions (y = −52). Enhanced functional activity was found during emotional scene perception (left panel) in ventral visual cortex (inferior occipital cortex, fusiform gyrus, and inferior temporal cortex), parietal cortex, thalamus, amygdala, and inferior frontal gyrus. During emotional imagery (right panel), enhanced functional activity was found in the amygdalae-hippocampal region, lateral cerebellum, vermis, and dorso-medial prefrontal cortex (dmPFC).

Figure 2.

A small overlap (yellow) between emotional scene perception (red) and emotional imagery (aqua) was found between the posterior portion of the amygdala and the anterior hippocampus. The functional cluster involved in emotional perception appears more anterior than the one involved in emotional imagery.

Figure 3.

Regions showing functional enhancement during pleasant, compared to unpleasant, processing in scene perception (red) and imagery (aqua), and their overlap (yellow) in the ventral medial prefrontal cortex (top) and striatum (bottom).

Figure 4.

Differences in functional activity when imagining personal (bold lines in the waveforms), compared to standard scenes (dotted lines in the waveforms) included regions in the posterior (top) and lateral (bottom) parietal cortex, such as precuneus, posterior cingulate cortex (pCC), and angular gyrus.