Poster Session B, Sunday, March 24, 8:00 – 10:00 am, Pacific Concourse
Reinstatement of mental context facilitates retrieval of extinction memories
Augustin C. Hennings1, Mason McClay1, Jarrod A. Lewis-Peacock1, Joseph E. Dunsmoor1; 1The University of Texas at Austin
Following fear conditioning, extinction learning introduces competition between fear and extinction memories (Bouton, M. E., 2002). The expression of extinction is contextually specific, whereas fear generalizes to novel contexts (Maren et al., 2013). Neurally, the acquisition and expression of extinction is regulated by a circuit including the ventro-medial prefrontal cortex (vmPFC), however many neuroimaging studies fail to observe vmPFC activity during extinction tests (Quirk & Mueller, 2008; Fullana et al., 2018). Recent models of human episodic memory emphasize mental context as an important factor for successful encoding and retrieval (Sederberg et al., 2008). Here, we hypothesized that reinstatement of mental context from extinction learning will facilitate the retrieval of extinction memories in a novel context. However, we did not expect to find this for patients with post-traumatic stress disorder (PTSD), a condition associated with deficits in contextual processing. One day after Pavlovian conditioning and extinction, healthy controls (N=20) and PTSD patients (N=20) were tested for fear renewal, and we used fMRI pattern classification to quantify the reinstatement of mental context from extinction learning using a “context-tagging” procedure (Gershman et al., 2013). In healthy controls, greater extinction context reinstatement was associated with better retrieval of extinction memories (i.e., fewer threat responses to CS+ items). There was no such relationship in the PTSD group. Moreover, our context reinstatement measures were significantly correlated with fMRI activity in the canonical extinction circuit, including vmPFC. These results show that context reinstatement helps resolve competition between fear and safety, but not for patients with PTSD.
Topic Area: EMOTION & SOCIAL: Emotion-cognition interactions