elf-relevant threat contexts enhance early processing of ear-conditioned faces

Anxiety states are characterized by attentional biases to threat and increased early brain responses to potentially threat signaling stimuli. How such stimuli are processed further depends on prior learning experiences (e.g. conditioning and extinction) and the context in which a stimulus appears. Whether context information and prior learning experiences interact with early threat processing in humans is largely unknown. Here, EEG was recorded while healthy participants (N = 20) viewed faces that were fearconditioned and/or extinguished 24 h before. Faces were either passively viewed or presented within different contexts, which were created by describing scenarios that could either involve participants motion regulation avlovian conditioning ace processing directly (self-threatening), or made them observers (other-threatening) of a potentially dangerous situation. Early brain responses (i.e., P1 amplitudes) were specifically enhanced during the self-threatening condition in response to non-extinguished versus extinguished fear-conditioned faces. This finding suggests that top-down contextual information is incorporated into early attention modulation of previously learned threat signals. © 2016 Elsevier B.V. All rights reserved. Being able to adequately process environmental threat signals s essential for survival across species, including humans. Accordngly, we are able to detect potentially harmful stimuli rapidly. resumably, this ability is especially pronounced in contexts assoiated with elevated danger. While the rapid detection of threat ignals is an important adaptive mechanism, in anxiety disorders, hich are associated with hypervigilance towards threat related timuli (Mathews & MacLeod, 2005), this ability could lead to a sigificant interference in normal life and reduce general well being. Most species can learn to show threat reactions to previously eutral stimuli by means of Pavlovian conditioning, where a neutral timulus turns into a conditioned stimulus (CS) and elicits a conitioned fear response after it has been (repeatedly) paired with This research was supported by a grant from the Deutsche Forschungsgemeinchaft to E.M. M. (DFG MU 3535/2-1). ∗ Corresponding author. E-mail addresses: hannah.muench@uni-tuebingen.de H.M. Muench), stefan.westermann@psy.unibe. ch (S. Westermann), ap@mclean.harvard. edu (D.A. Pizzagalli), shofmann@bu.edu (S.G. Hofmann), rik.mueller@staff.uni-marburg.de (E.M. Mueller). ttp://dx.doi. org/10.1016/j.biopsycho. 2016.07. 017 301-0511/© 2016 Elsevier B.V. All rights reserved. an aversive unconditioned stimulus (UCS). Through the mechanism of extinction, most species can also learn to no longer show threat reactions to previously fear-associated but now no longer danger-signaling cues. Extinction occurs following repeated CS presentation in the absence of the unconditioned stimulus (UCS) (Rescorla & Wagner, 1972). While the early model of Rescorla and Wagner (1972) postulated that extinction is a reversed learning process, recent models assume that an inhibitory association between CS and UCS is learned during extinction (Quirk, 2002). This leads to co-existing associations, whereby the CS signals both the presence and absence of danger (Bouton, Westbrook, Corcoran, Maren, 2006; Brooks and Bouton, 1994). Which association triggers the final response depends on several factors, including the context where learning took place (Hermans, Craske, Mineka, Lovibond, 2006; Milad et al., 2007). It has further been postulated that acquisition and consolidation of the extinction association underlie distinct mechanisms (Milad and Quirk, 2002; Mueller, Porter, Quirk, 2008; Mueller, Hofmann, Cherry, 2010). Accordingly, several brain imaging studies found distinct brain structures that are involved in either extinction acquisition or extinction retrieval (Hartley and Phelps, 2010;