Neural Circuitry Underlying the Regulation of Conditioned Fear and Its Relation to Extinction

Abstract

SUMMARY Recent efforts to translate basic research to the treatment of clinical disorders have led to a growing interest in exploring mechanisms for diminishing fear. This research has emphasized two approaches: extinction of conditioned fear, examined across species; and cognitive emotion regulation, unique to humans. Here, we sought to examine the similarities and differences in the neural mechanisms underlying these two paradigms for diminishing fear. Using an emotion regulation strategy, we examine the neural mechanisms of regulating conditioned fear using fMRI and compare the resulting activation pattern with that observed during classic extinction. Our results suggest that the lateral PFC regions engaged by cognitive emotion regulation strategies may influence the amygdala, diminishing fear through similar vmPFC connections that are thought to inhibit the amygdala during extinction. These findings further suggest that humans may have developed complex cognition that can aid in regulating emotional responses while utilizing phylogenetically shared mechanisms of extinction.

Transcranial direct current stimulation may modulate extinction memory in posttraumatic stress disorder

“…This protocol was designed to deliver current to the vmPFC and avoid cathodal effects on the prefrontal cortex. However, other brain regions involved in fear processing (i.e., the dorsolateral prefrontal cortex, Mungee et al., 2014; Asthana et al., 2013; Delgado, Nearing, LeDoux, & Phelps, 2008; and anterior cingulate cortex, Etkin, Egner, & Kalisch, 2011; Milad et al., 2007) may have been inadvertently stimulated. Also, tDCS was applied once for a duration of 10 min total and effects of tDCS may be expected to increase with greater duration and number of sessions (Brunoni et al., 2016).…”

Influence of Emotion on the Control of Low-Level Force Production

“…First, the threat of shock manipulation may be qualitatively different from the emotional image manipulation used in the current study. Although the threat of a painful shock is associated with excitation in emotion-related areas of the human brain that include amygdala (Delgado, Nearing, Ledoux, & Phelps, 2008), it also activates pain-related areas including thalamus, insula, somatosensory cortex, and anterior cingulate cortex (Bingel & Tracey, 2008;Oshiro, Quevedo, McHaffie, Kraft, & Coghill, 2009;Starr et al, 2009), Although a reciprocal relation has been demonstrated between emotion and motor systems as well as pain and motor systems (Del Santo, Gelli, Spidalieri, & Rossi. 2007;Hoeger Bement, Dicapo, Rasiarmos, & Hunter, 2008), it is plausible that the neural mechanism underlying these interactions may be different.…”

Generating value(s): Psychological value hierarchies reflect context-dependent sensitivity of the reward system

“…We expected regions classically involved in reward processing to be modulated by the different conditions in the two tasks, in particular striatum and amygdala (Delgado, 2007;Delgado, Nearing, LeDoux, & Phelps, 2008;Lieberman & Eisenberger, 2009). Additionally, we explored activation in the DMPFC, a region involved in impression formation and mentalizing (Frith & Frith, 1999;Mitchell et al, 2006).…”