Models and mechanisms of anxiety: evidence from startle studies

Grillon, Christian

doi:10.1007/s00213-007-1019-1

Cited by 397 publications

(366 citation statements)

References 143 publications

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“…In the first contemporary systematic examination of fear generalization gradients in humans, Lissek et al (2008) showed gradients of the eye-blink startle reflex to rings that varied in size from a ring paired with shock (CS+). The eye-blink (or fear-potentiated) startle reflex is an electromyographic response to a sudden stimulus that is potentiated in the presence of threat or during a state of anxiety, relative to a quiescent state (Grillon, 2008). During the acquisition phase, Lissek et al (2008) used a small and a large sized ring as CS+ and CS-, respectively.…”

Section: Perceptual Fear Generalizationmentioning

confidence: 99%

Fear Generalization in Humans: Systematic Review and Implications for Anxiety Disorder Research

et al. 2015

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Fear generalization, in which conditioned fear responses generalize or spread to related stimuli, is a defining feature of anxiety disorders. The behavioral consequences of maladaptive fear generalization are that aversive experiences with one stimulus or event may lead one to regard other cues or situations as potential threats that should be avoided, despite variations in physical form. Theoretical and empirical interest in the generalization of conditioned learning dates to the earliest research on classical conditioning in nonhumans. Recently, there has been renewed focus on fear generalization in humans due in part to its explanatory power in characterizing disorders of fear and anxiety. Here, we review existing behavioral and neuroimaging empirical research on the perceptual and non-perceptual (conceptual and symbolic) generalization of fear and avoidance in healthy humans and patients with anxiety disorders. The clinical implications of this research for understanding the etiology and treatment of anxiety is considered and directions for future research described.

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Section: Perceptual Fear Generalizationmentioning

confidence: 99%

Fear Generalization in Humans: Systematic Review and Implications for Anxiety Disorder Research

et al. 2015

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“…This hypothesis, however, is untested. Therefore, here we used a translational stress induction method in healthy humans (8,(10)(11)(12) to test the hypothesis that stress elevates aversive ventral striatum PE signal.Stress levels were modulated within subjects (n = 24) using a paradigm adapted from rodent studies: threat of foot shock (8,(10)(11)(12). Its impact upon the neural substrates of PE processing was established by recording striatal blood-oxygen-level-dependent (BOLD) signal from individuals completing a simple task designed to elicit matched appetitive (happy face) and aversive (fear face) prediction errors in the absence of behavioral confounds (Fig.…”

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confidence: 99%

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confidence: 99%

Stress increases aversive prediction error signal in the ventral striatum

Robinson

Overstreet

Charney

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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From job interviews to the heat of battle, it is evident that people think and learn differently when stressed. In fact, learning under stress may have long-term consequences; stress facilitates aversive conditioning and associations learned during extreme stress may result in debilitating emotional responses in posttraumatic stress disorder. The mechanisms underpinning such stress-related associations, however, are unknown. Computational neuroscience has successfully characterized several mechanisms critical for associative learning under normative conditions. One such mechanism, the detection of a mismatch between expected and observed outcomes within the ventral striatum (i.e., "prediction errors"), is thought to be a critical precursor to the formation of new stimulusoutcome associations. An untested possibility, therefore, is that stress may affect learning via modulation of this mechanism. Here we combine a translational model of stress with a cognitive neuroimaging paradigm to demonstrate that stress significantly increases ventral striatum aversive (but not appetitive) prediction error signal. This provides a unique account of the propensity to form threat-related associations under stress with direct implications for our understanding of both normal stress and stress-related disorders.threat of shock | punishment | anxiety | face perception L earning to associate cues with threat is adaptive because it allows future threat to be predicted and avoided (1). However, such associative learning also may lead to haunting and debilitating memories; the smell of stir-fry may evoke painful intrusive memories in Vietnam veterans. How aversive information is integrated to guide adaptive or maladaptive behavior, however, is not well understood. Here, we report that stress increases a key learning mechanism: the neural detection of a mismatch between an expected and observed aversive outcome within the ventral striatum, commonly referred to as the aversive prediction error (PE) signal (1, 2).Neurocomputational and neuroeconomic accounts of cognition posit that stimulus-outcome associations during conditioning are formed via temporal difference learning (1, 3, 4), in which learning depends upon comparing expectation to what is currently happening. New associations, it is argued, are driven by a difference between predicted and actual outcomes (i.e., "prediction errors"), with greater mismatch between expected and actual outcomes evoking greater PE, resulting in greater predictive learning. This mismatch gives rise to phasic dopamine release in the ventral striatum (1, 3-5) for both appetitive and aversive stimuli (1, 2, 6, 7). Little is known, however, about how PE processing might be affected by an organism's emotional state. Stress, for instance, is well known to facilitate aversive conditioning in both humans and animals (8, 9), raising the possibility that aversive PEs also might be increased by stress. This hypothesis, however, is untested. Therefore, here we used a translational stress induction method in healt...

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“…In particular, these studies have showed that when exposed to their phobic stimuli (e.g., spiders to a spider phobic), participants exhibit an enhanced activation of autonomic responses, as reflected by elevated skin conductance, startle responses and, more pertinent to the present study, hear rate acceleration (e.g., Carlsson et al., 2004; Globisch, Hamm, Esteves, & Öhman, 1999; Grillon, 2008; Öhman & Soares, 1994). As these pronounced psychophysiological responses to phobic stimuli are typically associated with intense subjective experiences of distress (for a review, see (McTeague et al., 2011), phobic individuals are often engaged in behavioral avoidance (for a review, see (Krypotos, Effting, Kindt, & Beckers, 2015).…”

Section: Discussionmentioning

confidence: 99%

The feasibility of an augment reality system to study the psychophysiological correlates of fear‐related responses

et al. 2018

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BackgroundPrevious studies have successfully used augmented reality (AR) as an aid to exposure‐based treatments for anxiety disorders. However, to the best of our knowledge, none of these studies have measured the physiological correlates of the fear response, relying solely on self‐reports and behavioral avoidance tests.MethodsAs the physiological defensive reactivity pattern impacts on the treatment effectiveness, we tested the feasibility of an AR system integrated in a mobile and wearable device for assessing the psychophysiological mechanisms (heart rate) involved in fear responses in real‐life contexts. Specific phobia was used as a model given its prototypical defensive hyperreactivity toward the feared stimulus (spiders to spider phobics, in the current study).ResultsThe results showed that the stimuli presented using AR were able to induce physiological alterations in the participants, which were specific depending on the stimulus type (fear or neutral) and on the participants’ level of spider fear (phobic and control group). These physiological correlates of the fear response were reflected both in the intensity of heart rate (in relation to the baseline) and in the time needed to react and recover after the stimulus exposure. Finally, we tested a theoretical model that showed that the physiological responses of phobic individuals when facing their phobic stimulus only explained its own data.ConclusionsWe argue in favor of the system's feasibility at capturing and quantifying the physiological dimension of fear‐related responses, which may be of great value for diagnostic and treatment purposes in anxiety disorders, namely specific phobia.

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Models and mechanisms of anxiety: evidence from startle studies

Cited by 397 publications

References 143 publications

Fear Generalization in Humans: Systematic Review and Implications for Anxiety Disorder Research

Fear Generalization in Humans: Systematic Review and Implications for Anxiety Disorder Research

Stress increases aversive prediction error signal in the ventral striatum

The feasibility of an augment reality system to study the psychophysiological correlates of fear‐related responses

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