Mental imagery can generate and regulate acquired differential fear conditioned reactivity

Abstract

Mental imagery is an important tool in the cognitive control of emotion. The present study tests the prediction that visual imagery can generate and regulate differential fear conditioning via the activation and prioritization of stimulus representations in early visual cortices. We combined differential fear conditioning with manipulations of viewing and imagining basic visual stimuli in humans. We discovered that mental imagery of a fear-conditioned stimulus compared to imagery of a safe conditioned stimulus generated a significantly greater conditioned response as measured by self-reported fear, the skin conductance response, and right anterior insula activity (experiment 1). Moreover, mental imagery effectively down- and up-regulated the fear conditioned responses (experiment 2). Multivariate classification using the functional magnetic resonance imaging data from retinotopically defined early visual regions revealed significant decoding of the imagined stimuli in V2 and V3 (experiment 1) but significantly reduced decoding in these regions during imagery-based regulation (experiment 2). Together, the present findings indicate that mental imagery can generate and regulate a differential fear conditioned response via mechanisms of the depictive theory of imagery and the biased-competition theory of attention. These findings also highlight the potential importance of mental imagery in the manifestation and treatment of psychological illnesses.

Fear in the Theater of the Mind: Differential Fear Conditioning With Imagined Stimuli

“…When investigating SCRs in Experiment 2, we observed a main effect: SCRs were greater to the CS+ than the CS−. The present study replicates the findings of Greening et al (2022), demonstrating that differential fear conditioning acquired to visual percepts generalizes to the corresponding imagined percepts. This finding is consistent with research showing that imagery of the CS can contribute to fear extinction (Agren et al, 2017; Jiang & Greening, 2021; Reddan et al, 2018) and fear reconsolidation (Grégoire & Greening, 2019).…”

“…This explanation cannot entirely be ruled out, though it may itself require mental imagery, as depictive mental imagery may underpin instructed fear conditioning (Olsson & Phelps, 2007). Nevertheless, our findings, along with those reported in previous literature, suggest that differential conditioning and generalization to imagined CS can occur, although the underlying mechanisms—be they depictive (Greening et al, 2022; Pearson et al, 2015), descriptive (Mertens et al, 2020; Mitchell et al, 2009), or some combination of both—remain up for debate (Ji et al, 2016). Future research on how the internal representations of mental images are stored and how they affect differential conditioning, potentially using brain imaging, is needed.…”

“…For example, following the acquisition of differential fear conditioning to visual percept, mental imagery of the CS can contribute to both fear extinction (Agren et al, 2017; Jiang & Greening, 2021; Reddan et al, 2018) and reconsolidation (Grégoire & Greening, 2019), as measured primarily via SCR. Consistent with the depictive theory, findings reported by Greening et al (2022) show both that imagery elicited significant differential reactivity, as measured with SCRs, self-reported fear, and anterior insula activity, and that imagery of the CSs was associated with significant multivoxel pattern classification in early visual cortices.…”

“…Along with other recent research involving mental imagery and fear (Hoppe et al, 2022; Koizumi et al, 2017; Reddan et al, 2018; Wicken et al, 2021), we interpret our findings as being consistent with the depictive theory, indicating that mental images activate early perceptual representations containing some geometric information of the physical stimulus without the stimulus being physically present (Pearson et al, 2015), and consistent with experience-dependent associative mechanisms (Johansen et al, 2011). For example, during imagery acquisition (Experiments 1 and 3), imagery of the CSs activates a neural representation in early visual regions, similar to the representation generated when one views the CS, leading to the subsequent activation of brain regions associated with the expression of fear conditioning such as the amygdala (Braem et al, 2017; Greening et al, 2022). This interpretation is consistent with our findings of robust self-reported imagery vividness and with previous research showing that imagery vividness is associated with early visual cortex functioning (Albers et al, 2013; Bergmann et al, 2016; Harrison & Tong, 2009).…”

“…The experiments were approved by the university's institutional review board. Sample sizes were determined on the basis of previous research involving fear conditioning and mental imagery (Greening et al, 2022).…”