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Song Y, Zhao S, Rong M, Liu Y, Gao Y, Chen W, Zhang D, Zheng X. The Impact of Continuous and Partial Reinforcement on the Acquisition and Generalization of Human-Conditioned Fear. Behav Sci (Basel) 2024; 14:630. [PMID: 39199026 PMCID: PMC11351138 DOI: 10.3390/bs14080630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/06/2024] [Accepted: 07/22/2024] [Indexed: 09/01/2024] Open
Abstract
Fear over-generalization as a core symptom of anxiety disorders is manifested by fear responses even to safe stimuli that are very dissimilar to the original dangerous stimulus. The present study investigated the effects of two separate conditioned stimuli-unconditioned stimuli (CS-US) pairing procedures on fear acquisition and generalization using a perceptual discrimination fear-conditioning paradigm, with US expectancy ratings and skin conductance response (SCR) as indicators. One group accepted continuous followed by partial CS-US pairings (C-P group); the other group accepted partial followed by continuous CS-US pairings (P-C group). It was found that compared to the P-C group, the C-P group showed stronger perceptual discrimination of CS+ and CS- in the fear acquisition and showed weaker SCRs and stronger extinction of US expectancy in the generalization. These findings emphasize that CS-US pairings significantly influence fear acquisition and generalization and suggest that continuous-following partial CS-US pairings promote individual discrimination of threat and safety signals and inhibit the generalization of conditioned fear. The results of this study have implications for clinical interventions for patients experiencing negative events.
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Affiliation(s)
- Yidan Song
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou 510631, China
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
| | - Shaochen Zhao
- Research Center for Guangdong-HongKong-Marcao Policing Model Innovation, China People’s Police University, Guangzhou 510663, China
| | - Muxin Rong
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou 510631, China
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
| | - Ying Liu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou 510631, China
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
| | - Yu Gao
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou 510631, China
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
| | - Wei Chen
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou 510631, China
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
| | - Donghuan Zhang
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou 510631, China
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
| | - Xifu Zheng
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou 510631, China
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China
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Ma Y, Jiao F, Batsikadze G, Yavari F, Nitsche MA. The impact of the left inferior frontal gyrus on fear extinction: A transcranial direct current stimulation study. Brain Stimul 2024; 17:816-825. [PMID: 38997105 DOI: 10.1016/j.brs.2024.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 06/03/2024] [Accepted: 07/06/2024] [Indexed: 07/14/2024] Open
Abstract
INTRODUCTION Fear extinction is a fundamental component of exposure-based therapies for anxiety-related disorders. The renewal of fear in a different context after extinction highlights the importance of contextual factors. In this study, we aimed to investigate the causal role of the left inferior frontal gyrus (LiFG) in the context-dependency of fear extinction learning via administration of transcranial direct current stimulation (tDCS) over this area. METHODS 180 healthy subjects were assigned to 9 groups: 3 tDCS conditions (anodal, cathodal, and sham) × 3 context combinations (AAA, ABA, and ABB). The fear conditioning/extinction task was conducted over three consecutive days: acquisition, extinction learning, and extinction recall. tDCS (2 mA, 10min) was administered during the extinction learning phase over the LiFG via a 4-electrode montage. Skin conductance response (SCR) data and self-report assessments were collected. RESULTS During the extinction learning phase, groups with excitability-enhancing anodal tDCS showed a significantly higher fear response to the threat cues compared to cathodal and sham stimulation conditions, irrespective of contextual factors. This effect was stable until the extinction recall phase. Additionally, excitability-reducing cathodal tDCS caused a significant decrease of the response difference between the threat and safety cues during the extinction recall phase. The self-report assessments showed no significant differences between the conditions throughout the experiment. CONCLUSION Independent of the context, excitability enhancement of the LiFG did impair fear extinction, and led to preservation of fear memory. In contrast, excitability reduction of this area enhanced fear extinction retention. These findings imply that the LiFG plays a role in the fear extinction network, which seems to be however context-independent.
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Affiliation(s)
- Yuanbo Ma
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Department of Psychology, Ruhr University Bochum, Bochum, Germany
| | - Fujia Jiao
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China
| | - Giorgi Batsikadze
- Department of Neurology and Center for Translational Neuro and Behavioral Sciences (C-TNBS), Essen University Hospital, University of Duisburg-Essen, Hufelandstraße 55, Essen, 45147, Germany
| | - Fatemeh Yavari
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
| | - Michael A Nitsche
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Bielefeld University, University Hospital OWL, Protestant Hospital of Bethel Foundation, University Clinic of Psychiatry and Psychotherapy, University Clinic of Child and Adolescent Psychiatry and Psychotherapy, Bielefeld, Germany; German Center for Mental Health (DZPG), Bochum, Germany.
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Skora LI, Scott RB, Jocham G. Stimulus awareness is necessary for both instrumental learning and instrumental responding to previously learned stimuli. Cognition 2024; 244:105716. [PMID: 38184894 DOI: 10.1016/j.cognition.2024.105716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/24/2023] [Accepted: 01/02/2024] [Indexed: 01/09/2024]
Abstract
Instrumental conditioning is a crucial part of adaptive behaviour, allowing agents to selectively interact with stimuli in their environment. Recent evidence suggests that instrumental conditioning cannot proceed without stimulus awareness. However, whether accurate unconscious instrumental responding can emerge from consciously acquired knowledge of the stimulus-action-outcome contingencies is unknown. We studied this question using instrumental trace conditioning, where participants learned to make approach/avoid decisions in two within-subject modes: conscious (stimuli in plain view) and unconscious (visually masked). Both tasks were followed by an unconscious-only instrumental performance task. We show that even when the contingencies are reliably learned in the conscious mode, participants fail to act upon them in the unconscious responding task. We also replicate the previous results that no instrumental learning occurs in the unconscious mode. Consequently, the absence of stimulus awareness not only precludes instrumental conditioning, but also precludes any kind of instrumental responding to already known stimuli. This suggests that instrumental behaviour is entirely supported by conscious awareness of the world, and corroborates the proposals that consciousness may be necessary for adaptive behaviours requiring selective action.
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Affiliation(s)
- Lina I Skora
- Biological Psychology of Decision Making, Institute of Experimental Psychology, Heinrich Heine University, 40225 Düsseldorf, Germany; School of Psychology, University of Sussex, Brighton BN1 9RH, UK.
| | - Ryan B Scott
- School of Psychology, University of Sussex, Brighton BN1 9RH, UK; Sussex Centre for Consciousness Science, University of Sussex, Brighton BN1 9RH, UK
| | - Gerhard Jocham
- Biological Psychology of Decision Making, Institute of Experimental Psychology, Heinrich Heine University, 40225 Düsseldorf, Germany
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Koenig-Robert R, El Omar H, Pearson J. Implicit bias training can remove bias from subliminal stimuli, restoring choice divergence: A proof-of-concept study. PLoS One 2023; 18:e0289313. [PMID: 37506067 PMCID: PMC10381032 DOI: 10.1371/journal.pone.0289313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Subliminal information can influence our conscious life. Subliminal stimuli can influence cognitive tasks, while endogenous subliminal neural information can sway decisions before volition. Are decisions inextricably biased towards subliminal information? Or can they diverge away from subliminal biases via training? We report that implicit bias training can remove biases from subliminal sensory primes. We first show that subliminal stimuli biased an imagery-content decision task. Participants (n = 17) had to choose one of two different patterns to subsequently imagine. Subliminal primes significantly biased decisions towards imagining the primed option. Then, we trained participants (n = 7) to choose the non-primed option, via post choice feedback. This training was successful despite participants being unaware of the purpose or structure of the reward schedule. This implicit bias training persisted up to one week later. Our proof-of-concept study indicates that decisions might not always have to be biased towards non-conscious information, but instead can diverge from subliminal primes through training.
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Affiliation(s)
- Roger Koenig-Robert
- Future Minds Lab, School of Psychology, University of New South Wales, Sydney, Australia
| | - Hashim El Omar
- Future Minds Lab, School of Psychology, University of New South Wales, Sydney, Australia
| | - Joel Pearson
- Future Minds Lab, School of Psychology, University of New South Wales, Sydney, Australia
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Chen Y, Chen S, Sun Z, Zhang X, Yuan X, Wang L, Jiang Y. Rapid Unconscious Acquisition of Conditioned Fear with Low-Spatial-Frequency but Emotionally Neutral Stimuli. RESEARCH (WASHINGTON, D.C.) 2023; 6:0181. [PMID: 37383220 PMCID: PMC10298222 DOI: 10.34133/research.0181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 06/02/2023] [Indexed: 06/30/2023]
Abstract
It has long been proposed that emotionally "prepared" (i.e., fear-related) stimuli are privileged in the unconscious acquisition of conditioned fear. However, as fear processing is suggested to highly depend on the coarse, low-spatial-frequency (LSF) components of the fear-related stimuli, it is plausible that LSF may play a unique role in the unconscious fear conditioning even with emotionally neutral stimuli. Here, we provided empirical evidence that, following classical fear conditioning, an invisible, emotionally neutral conditioned stimulus (CS+) with LSF, but not with high spatial frequency (HSF), can rapidly elicit stronger skin conductance responses (SCRs) and larger pupil diameters than its CS- counterpart. In comparison, consciously perceived emotionally neutral CS+ with LSF and HSF elicited comparable SCRs. Taken together, these results support that the unconscious fear conditioning does not necessarily entail emotionally prepared stimuli but prioritizes LSF information processing and highlight the crucial distinctions between the unconscious and the conscious fear learning. These findings not only coincide with the postulation that a rapid, spatial-frequency-dependent subcortical route is engaged in unconscious fear processing but also suggest the existence of multiple routes for conscious fear processing.
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Affiliation(s)
- Yujie Chen
- State Key Laboratory of Brain and Cognitive Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Si Chen
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhongju Sun
- State Key Laboratory of Brain and Cognitive Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Xilei Zhang
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiangyong Yuan
- State Key Laboratory of Brain and Cognitive Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Liang Wang
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yi Jiang
- State Key Laboratory of Brain and Cognitive Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- Chinese Institute for Brain Research, Beijing 102206, China
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6
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Feasibility of unconscious instrumental conditioning: A registered replication. Cortex 2023; 159:101-117. [PMID: 36621202 DOI: 10.1016/j.cortex.2022.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022]
Abstract
The extent to which high-level, complex functions can proceed unconsciously has been a topic of considerable debate. While unconscious processing has been demonstrated for a range of low-level processes, from feature integration to simple forms of conditioning and learning, theoretical contributions suggest that increasing complexity requires conscious access. Here, we focus our attention on instrumental conditioning, which has been previously shown to proceed without stimulus awareness. Yet, instrumental conditioning also involves integrating information over a large temporal scale and distinct modalities in order to deploy selective action, constituting a process of substantial complexity. With this in mind, we revisit the question of feasibility of instrumental conditioning in the unconscious domain. Firstly, we address the theoretical and practical considerations relevant to unconscious learning in general. Secondly, we aim to replicate the first study to show instrumental conditioning in the absence of stimulus awareness (Pessiglione et al., 2008), following the original design and supplementing the original crucial analyses with a Bayesian approach (Experiment 1). We found that apparent unconscious learning took place when replicating the original methods directly and according to the tests of awareness used. However, we could not establish that the full sample was unaware in a separate awareness check. We therefore attempted to replicate the effect yet again with improved methods to address the issues related to sensitivity and immediacy (Experiment 2), including an individual threshold-setting task and a trial-by-trial awareness check permitting exclusion of individual aware trials. Here, we found evidence for absence of unconscious learning. This result provides evidence that instrumental conditioning did not occur without stimulus awareness in this paradigm, supporting the view that complex forms of learning may rely on conscious access. Our results provides support for the proposal that perceptual consciousness may be necessary for complex, flexible processes, especially where selective action and behavioural adaptation are required.
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Webb EK, Etter JA, Kwasa JA. Addressing racial and phenotypic bias in human neuroscience methods. Nat Neurosci 2022; 25:410-414. [PMID: 35383334 PMCID: PMC9138180 DOI: 10.1038/s41593-022-01046-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 03/01/2022] [Indexed: 11/09/2022]
Abstract
Despite their premise of objectivity, neuroscience tools for physiological data collection, such as electroencephalography and functional near-infrared spectroscopy, introduce racial bias into studies by excluding individuals on the basis of phenotypic differences in hair type and skin pigmentation. Furthermore, at least one methodology-electrodermal activity recording (skin conductance responses)-may be influenced not only by potential phenotypic differences but also by negative psychological effects stemming from the lived experience of racism. Here we situate these issues within structural injustice, urge researchers to challenge racism in their scientific work and propose procedures and changes that may lead to more equitable science.
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Affiliation(s)
- E Kate Webb
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
- Division of Depression and Anxiety, McLean Hospital, Belmont, MA, USA.
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA.
| | - J Arthur Etter
- Department of Philosophy, McGill University, Montréal, QC, Canada
| | - Jasmine A Kwasa
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA, USA
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8
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Neurocircuitry of Contingency Awareness in Pavlovian Fear Conditioning. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2021; 21:1039-1053. [PMID: 33990933 DOI: 10.3758/s13415-021-00909-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/22/2021] [Indexed: 01/12/2023]
Abstract
In Pavlovian fear conditioning, contingency awareness provides an indicator of explicit fear learning. A less studied aspect of fear-based psychopathologies and their treatment, awareness of learned fear is a common cause of distress in persons with such conditions and is a focus of their treatment. The present work is a substudy of a broader fear-conditioning fMRI study. Following fear conditioning, we identified a subset of individuals who did not exhibit explicit awareness of the CS-US contingency. This prompted an exploratory analysis of differences in "aware" versus "unaware" individuals after fear conditioning. Self-reported expectancies of the CS-US contingency obtained immediately following fear conditioning were used to differentiate the two groups. Results corrected for multiple comparisons indicated significantly greater BOLD signal in the bilateral dlPFC, right vmPFC, bilateral vlPFC, left insula, left hippocampus, and bilateral amygdala for the CS+>CS- contrast in the aware group compared with the unaware group (all p values ≤ 0.004). PPI analysis with a left hippocampal seed indicated stronger coupling with the dlPFC and vmPFC in the aware group compared with the unaware group (all p values ≤ 0.002). Our findings add to our current knowledge of the networks involved in explicit learning and awareness of conditioned fear, with important clinical implications.
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Linton SR, Levita L. Potentiated perceptual neural responses to learned threat during Pavlovian fear acquisition and extinction in adolescents. Dev Sci 2021; 24:e13107. [PMID: 33817917 DOI: 10.1111/desc.13107] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 01/31/2021] [Accepted: 02/24/2021] [Indexed: 11/30/2022]
Abstract
Adolescents' experience of heightened anxiety and increased vulnerability to develop anxiety disorders is believed to partly result from blunted fear extinction processes. However, whether this anxiety is mediated by adolescent-specific differences in perceptual responses to learned threat is not known. To investigate this, we used EEG to examine reinforcement-dependent changes in early visual event-related potentials in adolescents (N = 28, 13-14 years) and adults (N = 23, 25-26 years old) during a differential Pavlovian fear conditioning task, with one conditioned stimulus (CS+) paired with an aversive sound (unconditioned stimulus [US]) on 50% of trials, and another (CS-) never paired with the US. An immediate extinction phase followed, where both CSs were presented alone. We found age-dependent dissociations between explicit and implicit measures of fear learning. Specifically, both adolescents and adults demonstrated successful fear conditioning and extinction according to their explicit awareness of changes in CS contingencies and their evaluative CS ratings, and their differential skin conductance responses. However, for the first time we show age differences at the neural level in perceptual areas. Only adolescents showed greater visual P1 and N1 responses to the CS+ compared to the CS- during acquisition, a dissociation that for the N1 was maintained during extinction. We suggest that the adolescent perceptual hyper-responsivity to learned threat and blunted extinction reported here could be an adaptive mechanism to protect adolescents from harm. However, this hyper-responsivity may also confer greater vulnerability to experience pathological levels of anxiety at this developmental stage.
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Affiliation(s)
| | - Liat Levita
- Department of Psychology, University of Sheffield, Sheffield, UK
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Purcell JB, Goodman AM, Harnett NG, Davis ES, Wheelock MD, Mrug S, Elliott MN, Emery ST, Schuster MA, Knight DC. Stress-elicited neural activity in young adults varies with childhood sexual abuse. Cortex 2021; 137:108-123. [PMID: 33609897 PMCID: PMC8044018 DOI: 10.1016/j.cortex.2020.12.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/25/2020] [Accepted: 12/18/2020] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Childhood physical and sexual abuse are stressful experiences that may alter the emotional response to future stressors. Stress-related emotional function is supported by brain regions that include the prefrontal cortex (PFC), hippocampus, and amygdala. The present study investigated whether childhood physical and sexual abuse are associated with stress-elicited brain activity in young adulthood. METHODS Participants (N = 300; Mage = 20.0; 151 female) completed a psychosocial stress task during functional magnetic resonance imaging (fMRI). Measures of physical and sexual abuse were included in a linear mixed effects model to estimate the unique relationship each type of childhood abuse had with stress-elicited brain activity. RESULTS Stress-elicited dorsolateral PFC, ventromedial PFC, and hippocampal activity decreased as the frequency of childhood sexual abuse increased. There were no regions in which stress-elicited activation varied with physical abuse. CONCLUSIONS The present findings suggest there is a unique relationship between childhood sexual abuse and the stress-elicited PFC and hippocampal activity of young adults that is not observed following childhood physical abuse. SIGNIFICANCE These findings may have important implications for understanding the mechanisms by which childhood sexual abuse impacts the development of future psychopathology.
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Affiliation(s)
- Juliann B Purcell
- University of Alabama at Birmingham, Department of Psychology, Birmingham, AL, USA.
| | - Adam M Goodman
- University of Alabama at Birmingham, Department of Psychology, Birmingham, AL, USA.
| | - Nathaniel G Harnett
- University of Alabama at Birmingham, Department of Psychology, Birmingham, AL, USA.
| | - Elizabeth S Davis
- University of Alabama at Birmingham, Department of Psychology, Birmingham, AL, USA.
| | - Muriah D Wheelock
- University of Alabama at Birmingham, Department of Psychology, Birmingham, AL, USA.
| | - Sylvie Mrug
- University of Alabama at Birmingham, Department of Psychology, Birmingham, AL, USA.
| | | | - Susan Tortolero Emery
- The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, Houston, TX, USA.
| | - Mark A Schuster
- Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - David C Knight
- University of Alabama at Birmingham, Department of Psychology, Birmingham, AL, USA.
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11
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Evidence that instrumental conditioning requires conscious awareness in humans. Cognition 2021; 208:104546. [DOI: 10.1016/j.cognition.2020.104546] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 12/21/2022]
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12
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Intranasal oxytocin decreases fear generalization in males, but does not modulate discrimination threshold. Psychopharmacology (Berl) 2021; 238:677-689. [PMID: 33241482 DOI: 10.1007/s00213-020-05720-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/13/2020] [Indexed: 10/22/2022]
Abstract
BACKGROUND A previously acquired fear response often spreads to perceptually or conceptually close stimuli or contexts. This process, known as fear generalization, facilitates the avoidance of danger, and dysregulations in this process play an important role in anxiety disorders. Oxytocin (OT) has been shown to modulate fear learning, yet effects on fear generalization remain unknown. METHODS We employed a randomized, placebo-controlled, double-blind, between-subject design during which healthy male participants received either intranasal OT or placebo (PLC) following fear acquisition and before fear generalization with concomitant acquisition of skin conductance responses (SCRs). Twenty-four to 72 h before the fear learning and immediately after the fear generalization task, participants additionally complete a discrimination threshold task. RESULTS Relative to PLC, OT significantly reduced perceived risk and SCRs towards the CS+ and GS1 (the generalization stimulus that is most similar to CS+) during fear generalization, whereas the discrimination threshold was not affected. CONCLUSIONS Together, the results suggest that OT can attenuate fear generalization in the absence of effects on discrimination threshold. This study provides the first evidence for effects of OT on fear generalization in humans and suggests that OT may have therapeutic potential in anxiety disorders characterized by dysregulated fear generalization.
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13
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Measuring learning in human classical threat conditioning: Translational, cognitive and methodological considerations. Neurosci Biobehav Rev 2020; 114:96-112. [DOI: 10.1016/j.neubiorev.2020.04.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 04/15/2020] [Accepted: 04/18/2020] [Indexed: 02/06/2023]
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Taylor JE, Lau H, Seymour B, Nakae A, Sumioka H, Kawato M, Koizumi A. An Evolutionarily Threat-Relevant Odor Strengthens Human Fear Memory. Front Neurosci 2020; 14:255. [PMID: 32425741 PMCID: PMC7212458 DOI: 10.3389/fnins.2020.00255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/06/2020] [Indexed: 11/13/2022] Open
Abstract
Olfaction is an evolutionary ancient sense, but it remains unclear to what extent it can influence routine human behavior. We examined whether a threat-relevant predator odor (2-methyl-2-thiazoline) would contextually enhance the formation of human fear memory associations. Participants who learned to associate visual stimuli with electric shock in this predator odor context later showed stronger fear responses to the visual stimuli than participants who learned in an aversiveness-matched control odor context. This effect generalized to testing in another odor context, even after extinction training. Results of a separate experiment indicate that a possible biological mechanism for this effect may be increased cortisol levels in a predator odor context. These results suggest that innate olfactory processes can play an important role in human fear learning. Modulatory influences of odor contexts may partly explain the sometimes maladaptive persistence of human fear memory, e.g., in post-traumatic stress disorders.
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Affiliation(s)
- Jessica E Taylor
- Department of Decoded Neurofeedback (DecNef), Computational Neuroscience Laboratories, Advanced Telecommunications Research Institute International, Kyoto, Japan
| | - Hakwan Lau
- Department of Decoded Neurofeedback (DecNef), Computational Neuroscience Laboratories, Advanced Telecommunications Research Institute International, Kyoto, Japan.,Department of Psychology, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Psychology, University of Hong Kong, Pokfulam, Hong Kong
| | - Ben Seymour
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Osaka, Japan.,Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom.,Department of Neural Computation for Decision-Making, Cognitive Mechanisms Laboratories, Advanced Telecommunications Research Institute International, Kyoto, Japan
| | - Aya Nakae
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Hidenobu Sumioka
- Hiroshi Ishiguro Laboratories, Advanced Telecommunications Research Institute International, Kyoto, Japan
| | - Mitsuo Kawato
- Department of Decoded Neurofeedback (DecNef), Computational Neuroscience Laboratories, Advanced Telecommunications Research Institute International, Kyoto, Japan.,Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Osaka, Japan
| | - Ai Koizumi
- Department of Decoded Neurofeedback (DecNef), Computational Neuroscience Laboratories, Advanced Telecommunications Research Institute International, Kyoto, Japan.,Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Osaka, Japan.,Sony Computer Science Laboratories, Inc., Tokyo, Japan
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15
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Bolaram A, Coe TE, Power JM, Cheng DT. Awareness and differential eyeblink conditioning: effects of manipulating auditory CS frequencies. ACTA ACUST UNITED AC 2020; 27:78-82. [PMID: 31949039 PMCID: PMC6970424 DOI: 10.1101/lm.050146.119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 11/22/2019] [Indexed: 11/24/2022]
Abstract
The role of awareness in differential delay eyeblink conditioning (EBC) has been a topic of much debate. We tested the idea that awareness is required for differential delay EBC when two cues are perceptually similar. The present study manipulated frequencies of auditory conditioned stimuli (CS) to vary CS similarity in three groups of participants. Our findings indicate that awareness was not necessary for differential delay EBC when two tones are easily discriminable, awareness was also not needed for relatively similar tones but may facilitate earlier conditioning, and awareness alone was not sufficient for differential delay EBC.
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Affiliation(s)
- Anudeep Bolaram
- Department of Psychology, Auburn University, Auburn, Alabama 36849, USA
| | - Taylor E Coe
- Department of Psychology, Auburn University, Auburn, Alabama 36849, USA
| | - John M Power
- Department of Physiology, University of New South Wales, Sydney 2052, Australia
| | - Dominic T Cheng
- Department of Psychology, Auburn University, Auburn, Alabama 36849, USA
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16
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Mertens G, Engelhard IM. A systematic review and meta-analysis of the evidence for unaware fear conditioning. Neurosci Biobehav Rev 2020; 108:254-268. [DOI: 10.1016/j.neubiorev.2019.11.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 11/12/2019] [Accepted: 11/15/2019] [Indexed: 01/23/2023]
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17
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Zaman J, Van de Pavert I, Van Oudenhove L, Van Diest I. The use of stimulus perception to account for variability in skin conductance responses to interoceptive stimuli. Psychophysiology 2019; 57:e13494. [PMID: 31608999 DOI: 10.1111/psyp.13494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/05/2019] [Accepted: 07/02/2019] [Indexed: 01/27/2023]
Abstract
Activity of the electrodermal response system is customarily expressed in relation to physical stimulus properties and not to perceived features. In situations where the delivery of physically identical stimuli can be challenging, such as in interoception research, this variability might pose a challenge for contemporary SCR analyses. Therefore, we investigated the extent to which activity in the electrodermal response system triggered by the delivery of interoceptive stimuli is better predicted by perceived intensity rather than physical input. For this purpose, we reanalyzed data from the baseline phase of a previous study (n = 60) in which skin conductance responses (SCRs) to innocuous esophageal stimulations of high and low intensities were recorded in addition to categorizations based on their perceived intensity (high or low). Using both peak scoring and model inversion methods, we found that the inclusion of stimulus perception as a predictor of the magnitude of the SCR increased model fit. These findings suggest that the inclusion of perception is a promising avenue to better model variability in psychophysiological responses to interoceptive stimuli.
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Affiliation(s)
- Jonas Zaman
- Department of Health Psychology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium.,Center for the Psychology of Learning and Experimental Psychopathology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
| | - Iris Van de Pavert
- Department of Health Psychology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
| | - Lukas Van Oudenhove
- Laboratory for Brain-Gut Axis Studies (LaBGAS), Translational Research Centre for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism, and Ageing, KU Leuven, Leuven, Belgium.,Consultation-Liaison Psychiatry, University Psychiatric Centre KU Leuven, Leuven, Belgium
| | - Ilse Van Diest
- Department of Health Psychology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
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18
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Implicit and explicit systems differently predict possible dangers. Sci Rep 2019; 9:13367. [PMID: 31527740 PMCID: PMC6746769 DOI: 10.1038/s41598-019-49751-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/29/2019] [Indexed: 12/19/2022] Open
Abstract
One strategy to address new potential dangers is to generate defensive responses to stimuli that remind learned threats, a phenomenon called fear generalization. During a threatening experience, the brain encodes implicit and explicit memory traces. Nevertheless, there is a lack of studies comparing implicit and explicit response patterns to novel stimuli. Here, by adopting a discriminative threat conditioning paradigm and a two-alternative forced-choice recognition task, we found that the implicit reactions were selectively elicited by the learned threat and not by a novel similar but perceptually discriminable stimulus. Conversely, subjects explicitly misidentified the same novel stimulus as the learned threat. This generalization response was not due to stress-related interference with learning, but related to the embedded threatening value. Therefore, we suggest a dissociation between implicit and explicit threat recognition profiles and propose that the generalization of explicit responses stems from a flexible cognitive mechanism dedicated to the prediction of danger.
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19
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Bräscher AK, Witthöft M. Nocebo hyperalgesia induced by implicit conditioning. J Behav Ther Exp Psychiatry 2019; 64:106-112. [PMID: 30952053 DOI: 10.1016/j.jbtep.2019.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 03/11/2019] [Accepted: 03/26/2019] [Indexed: 12/01/2022]
Abstract
BACKGROUND AND OBJECTIVES Nocebo hyperalgesia (i.e., increased pain sensitivity based on expectations) can be induced by conditioning, but is supposed to be mediated by conscious expectation. Although recent evidence points to the feasibility of subliminal conditioning of nocebo hyperalgesia with masked faces, face processing might be a special case and the practical implications of subliminal conditioning remain questionable. This study aimed to implicitly condition nocebo hyperalgesia using supraliminal cues. METHODS Implicit differential nocebo conditioning (N = 48 healthy participants) was implemented by coupling high and low painful electric stimuli to varying visual stimuli that only differed in the symmetry/asymmetry of one component (CS+/CS-) and contained further distracting components. In the test phase, only the low painful stimulus followed both CS to test for conditioned nocebo effects in intensity and aversiveness ratings and electrodermal activity. A behavioral contingency test and a post-experimental questionnaire assessed contingency awareness. RESULTS A conditioned effect emerged in the aversiveness (p = .036; η2 = 0.09), but not in the intensity rating (p = .195) while controlling for contingency awareness. Further, increased skin conductance levels in response to CS + emerged, irrespective of contingency awareness (p = .014, η2 = 0.13). No conditioned responses in skin conductance responses emerged (p = .872). LIMITATIONS Expected effects only emerged in part of the outcome variables. CONCLUSIONS The results support the notion that implicit conditioning of nocebo hypoalgesia is feasible using a novel experimental conditioning design with supraliminal stimulus presentation, although further research is needed. So far, implicitly conditioned nocebo effects might have been underestimated despite vast clinical implications.
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Affiliation(s)
- Anne-Kathrin Bräscher
- Department for Clinical Psychology, Psychotherapy, and Experimental Psychopathology, Johannes Gutenberg University Mainz, Germany.
| | - Michael Witthöft
- Department for Clinical Psychology, Psychotherapy, and Experimental Psychopathology, Johannes Gutenberg University Mainz, Germany
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20
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Ultrafast Cortical Gain Adaptation in the Human Brain by Trial-To-Trial Changes of Associative Strength in Fear Learning. J Neurosci 2018; 38:8262-8276. [PMID: 30104342 DOI: 10.1523/jneurosci.0977-18.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/19/2018] [Accepted: 07/22/2018] [Indexed: 12/11/2022] Open
Abstract
In fear conditioning, more efficient sensory processing of a stimulus (the conditioned stimulus, CS) that has acquired motivational relevance by being paired with an aversive event (the unconditioned stimulus, US) has been associated with increased cortical gain in early sensory brain areas (Miskovic and Keil, 2012). Further, this sensory gain modulation related to short-term plasticity changes occurs independently of aware cognitive anticipation of the aversive US, pointing toward implicit learning mechanisms (Moratti and Keil, 2009). However, it is unknown how quickly the implicit learning of CS-US associations results in the adaptation of cortical gain. Here, using steady-state visually evoked fields derived from human Magnetoencephalography (MEG) recordings in two experiments (N = 33, 17 females and 16 males), we show that stimulus-driven neuromagnetic oscillatory activity increases and decreases quickly as a function of associative strength within three or four trials, as predicted by a computationally implemented Rescorla-Wagner model with the highest learning rate. These ultrafast cortical gain adaptations are restricted to early visual cortex using a delay fear conditioning procedure. Short interval (500 ms) trace conditioning resulted in the same ultrafast activity modulations by associative strength, but in a complex occipito-parieto-temporo-frontal network. Granger causal analysis revealed that reverberating top-down and bottom-up influences between anterior and posterior brain regions during trace conditioning characterized this network. Critically, in both delay and trace conditioning, ultrafast cortical gain modulations as a function of associative strength occurred independently of conscious US anticipation.SIGNIFICANCE STATEMENT In ever-changing environments, learned associations between a cue and an aversive consequence must change under new stimulus-consequence contingencies to be adaptive. What predicts potential dangers now might be meaningless in the next situation. Predictive cues are prioritized, as reflected by increased sensory cortex activity for these cues. However, this modulation also must adapt to altered stimulus-consequence contingencies. Here, we show that human visual cortex activity can be modulated quickly according to ultrafast contingency changes within a few learning trials. This finding extends to frontal brain regions when the cue and the aversive event are separated in time. Critically, this ultrafast updating process occurs orthogonally to aware aversive outcome anticipation and therefore relies on unconscious implicit learning mechanisms.
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21
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Xu L, Su H, Xie X, Yan P, Li J, Zheng X. The Topological Properties of Stimuli Influence Fear Generalization and Extinction in Humans. Front Psychol 2018; 9:409. [PMID: 29643824 PMCID: PMC5882815 DOI: 10.3389/fpsyg.2018.00409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 03/12/2018] [Indexed: 11/16/2022] Open
Abstract
Fear generalization is an etiologically significant indicator of anxiety disorders, and understanding how to inhibit it is important in their treatment. Prior studies have found that reducing fear generalization using a generalization stimulus (GS) is ineffective in removing a conditioned fear that incorporates local features, and that topological properties appear to play a comparatively more significant role in the processes of perception and categorization. Our study utilized a conditioned-fear generalization design to examine whether the topological properties of stimuli influence the generalization and return of fear. Fear was indexed using online expectancy ratings and skin conductance responses (SCRs). The study's 52 participants were divided into three groups: Group 1, conditioned danger cue (CS+) extinction; Group 2, extinction of one GS; Group 3, extinction of three GSs. We found that the three groups acquired conditioned fear at the same level. In the generalization and extinction phase, fear was transferred to the GS with the same topological properties as CS+, and gradual decreases in both shock expectancy and SCRs over non-reinforced extinction trials were observed. In the test phase, participants' online expectancy ratings indicated that fear did not return in Group 1, but did return in Groups 2 and 3. All three groups demonstrated successful GS fear extinction, but only Group 1 did not show a return of fear for CS+. Regarding SCRs results, none of the groups demonstrated a return of fear, suggesting that utilization of topological properties successfully reduced the return of conditioned fear. Our results indicate that, in clinical settings, using GS with topological equivalence to CS+ might offer a potential method with which to extinct conditioned fear.
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Affiliation(s)
- Liang Xu
- School of Psychology, South China Normal University, Guangzhou, China
- Department of Humanities and Social Sciences, Guangdong Communication Polytechnic, Guangzhou, China
| | - Hongyu Su
- School of Psychology, South China Normal University, Guangzhou, China
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Xiaoyuan Xie
- School of Psychology, South China Normal University, Guangzhou, China
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Pei Yan
- School of Psychology, South China Normal University, Guangzhou, China
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Junjiao Li
- School of Psychology, South China Normal University, Guangzhou, China
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Xifu Zheng
- School of Psychology, South China Normal University, Guangzhou, China
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
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22
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Jensen KB. What Is Minimally Required to Elicit Placebo Effects? INTERNATIONAL REVIEW OF NEUROBIOLOGY 2018; 138:181-199. [PMID: 29681325 DOI: 10.1016/bs.irn.2018.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Placebo effects have often been attributed to cognitive processes described as "learning" and/or "expectancy," yet the role of conscious awareness is unclear. Furthermore, little is known about the placebo effects in patients with limited cognitive abilities, such as intellectual disability. Here, recent data on placebo mechanisms in patients with impaired cognitive function will be discussed, as well as experimental studies investigating how implicit cognitive processes may shape placebo effects. Together these studies comment on the minimum requirements in order to elicit placebo effects, both from the view of conscious awareness and from the perspective of Intelligence Quotient and basic brain function. Together with recent conceptualizations of placebo effects in terms of predictive coding, there is evidence to suggest that placebo effects are fundamental responses of the brain that have developed to promote survival.
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23
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Multiple reward-cue contingencies favor expectancy over uncertainty in shaping the reward-cue attentional salience. PSYCHOLOGICAL RESEARCH 2018; 83:332-346. [PMID: 29372304 DOI: 10.1007/s00426-017-0960-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 12/06/2017] [Indexed: 10/18/2022]
Abstract
Reward-predicting cues attract attention because of their motivational value. A debated question regards the conditions under which the cue's attentional salience is governed more by reward expectancy rather than by reward uncertainty. To help shedding light on this relevant issue, here, we manipulated expectancy and uncertainty using three levels of reward-cue contingency, so that, for example, a high level of reward expectancy (p = .8) was compared with the highest level of reward uncertainty (p = .5). In Experiment 1, the best reward-cue during conditioning was preferentially attended in a subsequent visual search task. This result was replicated in Experiment 2, in which the cues were matched in terms of response history. In Experiment 3, we implemented a hybrid procedure consisting of two phases: an omission contingency procedure during conditioning, followed by a visual search task as in the previous experiments. Crucially, during both phases, the reward-cues were never task relevant. Results confirmed that, when multiple reward-cue contingencies are explored by a human observer, expectancy is the major factor controlling both the attentional and the oculomotor salience of the reward-cue.
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24
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Bräscher AK, Kleinböhl D, Hölzl R, Becker S. Differential Classical Conditioning of the Nocebo Effect: Increasing Heat-Pain Perception without Verbal Suggestions. Front Psychol 2017; 8:2163. [PMID: 29321752 PMCID: PMC5733554 DOI: 10.3389/fpsyg.2017.02163] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/28/2017] [Indexed: 01/08/2023] Open
Abstract
Background: Nocebo effects, including nocebo hyperalgesia, are a common phenomenon in clinical routine with manifold negative consequences. Both explicit expectations and learning by conditioning are known to induce nocebo effects, but the specific role of conditioning remains unclear, because conditioning is rarely implemented independent of verbal suggestions. Further, although pain is a multidimensional phenomenon, nocebo effects are usually assessed in subjective ratings only, neglecting, e.g., behavioral aspects. The aim of this study was to test whether nocebo hyperalgesia can be learned by conditioning without explicit expectations, to assess nocebo effects in different response channels, and to exploratively assess, whether contingency awareness is a necessary condition for conditioned nocebo hyperalgesia. Methods: Twenty-one healthy volunteers were classically conditioned using painful and non-painful heat stimuli that followed two different cues. The conditioned nocebo effect was assessed by subjective ratings of perceived stimulation intensity on a visual analog scale and a behavioral discrimination task, assessing sensitization and habituation in response to the same stimulation following the two cues. Results: Results show a conditioned nocebo effect indicated by the subjective intensity ratings. Conditioned effects were also seen in the behavioral responses, but paradoxically, behavioral responses indicated decreased perception after conditioning, but only for subjects successfully conditioned as indicated by the subjective ratings. Explorative analyses suggested that awareness of the contingencies and the different cues was not necessary for successful conditioning. Conclusion: Nocebo effects can be learned without inducing additional explicit expectations. The dissociation between the two response channels, possibly representing the conditioned and a compensatory response, highlights the importance of considering different outcomes in nocebo responses to fully understand underlying mechanisms. The present results challenge the role of explicit expectations in conditioned nocebo effects and are relevant with implications in clinical contexts, e.g., when transient adverse effects become conditioned.
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Affiliation(s)
- Anne-Kathrin Bräscher
- Otto-Selz-Institute of Applied Psychology, Mannheim Centre for Work and Health, University of Mannheim, Mannheim, Germany.,Department for Clinical Psychology, Psychotherapy, and Experimental Psychopathology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Dieter Kleinböhl
- Otto-Selz-Institute of Applied Psychology, Mannheim Centre for Work and Health, University of Mannheim, Mannheim, Germany.,Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Rupert Hölzl
- Otto-Selz-Institute of Applied Psychology, Mannheim Centre for Work and Health, University of Mannheim, Mannheim, Germany.,Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Susanne Becker
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.,Alan Edwards Centre for Research on Pain, Faculty of Dentistry, McGill University, Montreal, QC, Canada
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25
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Goodman AM, Harnett NG, Knight DC. Pavlovian conditioned diminution of the neurobehavioral response to threat. Neurosci Biobehav Rev 2017; 84:218-224. [PMID: 29203422 DOI: 10.1016/j.neubiorev.2017.11.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 11/16/2017] [Accepted: 11/30/2017] [Indexed: 01/20/2023]
Abstract
An important function of emotion is that it motivates us to respond more effectively to threats in our environment. Accordingly, healthy emotional function depends on the ability to appropriately avoid, escape, or defend against threats we encounter. Thus, from a functional perspective, it is important to understand the emotional response to threat. However, prior work has largely focused on the emotional response in anticipation of threat, rather than the emotional response to the threat itself. The current review is focused on recent behavioral, psychophysiological, and neural findings from Pavlovian conditioning research that is centered on the expression and regulation of the emotional response to threat. The current evidence suggests that a neural network that includes the prefrontal cortex, hippocampus, and amygdala underlies learning, expression, and regulation processes that modulate emotional responses to threat. This line of research has important implications for our understanding of emotion regulation and stress resilience.
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Affiliation(s)
- Adam M Goodman
- Department of Psychology, University of Alabama at Birmingham, CIRC 235 H, 1720 2nd Avenue South, Birmingham, AL 35294-1170, United States
| | - Nathaniel G Harnett
- Department of Psychology, University of Alabama at Birmingham, CIRC 235 H, 1720 2nd Avenue South, Birmingham, AL 35294-1170, United States
| | - David C Knight
- Department of Psychology, University of Alabama at Birmingham, CIRC 235 H, 1720 2nd Avenue South, Birmingham, AL 35294-1170, United States.
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26
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Moratti S, Giménez-Fernández T, Méndez-Bértolo C, de Vicente-Pérez F. Conditioned inhibitory and excitatory gain modulations of visual cortex in fear conditioning: Effects of analysis strategies of magnetocortical responses. Psychophysiology 2017; 54:882-893. [PMID: 28169431 DOI: 10.1111/psyp.12841] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 01/05/2017] [Indexed: 11/29/2022]
Abstract
In unpredictable environments, stimuli that predict potential danger or its absence can change rapidly. Therefore, it is highly adaptive to prioritize incoming sensory information flexibly as a function of prior experience. Previously, these changes have only been conceptualized as excitatory gain increases in sensory cortices for acquired fear-relevant stimuli during associative learning. However, formal descriptions of associative processes by Rescorla and Wagner predict both conditioned excitatory and inhibitory processes in response systems for fear and safety cues, respectively. Magnetocortical steady-state visual evoked fields (ssVEFs) have been shown to vary in amplitude as a function of associative strength. Therefore, we wondered why previous studies reporting ssVEF modulations by fear learning did not observe conditioned inhibition of ssVEF responses for the safety cue. Three analysis strategies were applied: (1) traditional analysis of ssVEF amplitude at occipital MEG sensors, (2) applying a general linear model (GLM) at each sensor, and (3) fitting the same GLM to cortically localized ssVEF responses. First, we replicated previous findings of increased ssVEFs for acquired fear-relevant stimuli using all three analysis strategies. Critically, we demonstrated conditioned inhibition of ssVEF responses for fear-irrelevant cues for specific gradiometer sensor types using the traditional analysis technique and for all sensor types when applying a GLM to the sensor space. However, sensor space effects were rather small. In stark contrast, cortical source space effect sizes were most pronounced. The results of opposing CS+ and CS- modulations in sensory cortex reflect predictions of the Rescorla-Wagner model and current neurobiological findings.
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Affiliation(s)
- Stephan Moratti
- Department of Basic Psychology I, Complutense University of Madrid, Madrid, Spain.,Laboratory of Clinical Neuroscience, Center for Biomedical Technology, Polytechnic University of Madrid, Madrid, Spain.,Laboratory for Cognitive and Computational Neuroscience, Polytechnic University of Madrid, Madrid, Spain
| | | | - Constantino Méndez-Bértolo
- Laboratory of Clinical Neuroscience, Center for Biomedical Technology, Polytechnic University of Madrid, Madrid, Spain
| | - Francisco de Vicente-Pérez
- Department of Basic Psychology I, Complutense University of Madrid, Madrid, Spain.,Laboratory for Cognitive and Computational Neuroscience, Polytechnic University of Madrid, Madrid, Spain
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27
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Koizumi A, Amano K, Cortese A, Shibata K, Yoshida W, Seymour B, Kawato M, Lau H. Fear reduction without fear through reinforcement of neural activity that bypasses conscious exposure. Nat Hum Behav 2016; 1. [PMID: 28989977 DOI: 10.1038/s41562-016-0006] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ai Koizumi
- Dept. of Decoded Neurofeedback, ATR Cognitive Mechanisms Laboratories, Address: 2-2-2, Hikaridai, Seika-cho, Sorakugun, Kyoto, 619-0288, JAPAN.,Dept. of Psychology, Columbia University, Address: 1190 Amsterdam Ave. 370 Schermerhorn Ext. MC:5501, New York, 10027, USA.,Center for Information and Neural Networks (CiNet), NICT, Address: 1-4 Yamadaoka, Suita City, Osaka, 565-0871, JAPAN
| | - Kaoru Amano
- Center for Information and Neural Networks (CiNet), NICT, Address: 1-4 Yamadaoka, Suita City, Osaka, 565-0871, JAPAN
| | - Aurelio Cortese
- Dept. of Decoded Neurofeedback, ATR Cognitive Mechanisms Laboratories, Address: 2-2-2, Hikaridai, Seika-cho, Sorakugun, Kyoto, 619-0288, JAPAN.,Center for Information and Neural Networks (CiNet), NICT, Address: 1-4 Yamadaoka, Suita City, Osaka, 565-0871, JAPAN.,Graduate School of Information Science, Nara Institute of Science and Technology, Address: 8916-5 Takayama, Ikoma Nara, 630-0192, JAPAN.,Dept. of Psychology, UCLA, Address: BOX 951563, Los Angeles, CA 90095-1563, USA
| | - Kazuhisa Shibata
- Dept. of Decoded Neurofeedback, ATR Cognitive Mechanisms Laboratories, Address: 2-2-2, Hikaridai, Seika-cho, Sorakugun, Kyoto, 619-0288, JAPAN.,Dept. of Psychology, Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, JAPAN 464-8601, JAPAN
| | - Wako Yoshida
- Dept. of Decoded Neurofeedback, ATR Cognitive Mechanisms Laboratories, Address: 2-2-2, Hikaridai, Seika-cho, Sorakugun, Kyoto, 619-0288, JAPAN.,Center for Information and Neural Networks (CiNet), NICT, Address: 1-4 Yamadaoka, Suita City, Osaka, 565-0871, JAPAN.,Dept. of Engineering, University of Cambridge, Address: Trumpington St, Cambridge CB2 1PZ, UK
| | - Ben Seymour
- Dept. of Decoded Neurofeedback, ATR Cognitive Mechanisms Laboratories, Address: 2-2-2, Hikaridai, Seika-cho, Sorakugun, Kyoto, 619-0288, JAPAN.,Center for Information and Neural Networks (CiNet), NICT, Address: 1-4 Yamadaoka, Suita City, Osaka, 565-0871, JAPAN.,Dept. of Engineering, University of Cambridge, Address: Trumpington St, Cambridge CB2 1PZ, UK
| | - Mitsuo Kawato
- Dept. of Decoded Neurofeedback, ATR Cognitive Mechanisms Laboratories, Address: 2-2-2, Hikaridai, Seika-cho, Sorakugun, Kyoto, 619-0288, JAPAN.,Graduate School of Information Science, Nara Institute of Science and Technology, Address: 8916-5 Takayama, Ikoma Nara, 630-0192, JAPAN
| | - Hakwan Lau
- Dept. of Psychology, Columbia University, Address: 1190 Amsterdam Ave. 370 Schermerhorn Ext. MC:5501, New York, 10027, USA.,Dept. of Psychology, UCLA, Address: BOX 951563, Los Angeles, CA 90095-1563, USA.,Brain Research Institute, UCLA, Address: Box 951761, Los Angeles, CA 90095-1761, USA
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28
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Evidence of trace conditioning in comatose patients revealed by the reactivation of EEG responses to alerting sounds. Neuroimage 2016; 141:530-541. [DOI: 10.1016/j.neuroimage.2016.07.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/08/2016] [Accepted: 07/17/2016] [Indexed: 11/20/2022] Open
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29
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White EC, Graham BM. Estradiol levels in women predict skin conductance response but not valence and expectancy ratings in conditioned fear extinction. Neurobiol Learn Mem 2016; 134 Pt B:339-48. [DOI: 10.1016/j.nlm.2016.08.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 07/31/2016] [Accepted: 08/17/2016] [Indexed: 01/03/2023]
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30
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Probing the influence of unconscious fear-conditioned visual stimuli on eye movements. Conscious Cogn 2016; 46:60-70. [PMID: 27684607 DOI: 10.1016/j.concog.2016.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/08/2016] [Accepted: 09/17/2016] [Indexed: 11/22/2022]
Abstract
Efficient threat detection from the environment is critical for survival. Accordingly, fear-conditioned stimuli receive prioritized processing and capture overt and covert attention. However, it is unknown whether eye movements are influenced by unconscious fear-conditioned stimuli. We performed a classical fear-conditioning procedure and subsequently recorded participants' eye movements while they were exposed to fear-conditioned stimuli that were rendered invisible using interocular suppression. Chance-level performance in a forced-choice-task demonstrated unawareness of the stimuli. Differential skin conductance responses and a change in participants' fearfulness ratings of the stimuli indicated the effectiveness of conditioning. However, eye movements were not biased towards the fear-conditioned stimulus. Preliminary evidence suggests a relation between the strength of conditioning and the saccadic bias to the fear-conditioned stimulus. Our findings provide no strong evidence for a saccadic bias towards unconscious fear-conditioned stimuli but tentative evidence suggests that such an effect may depend on the strength of the conditioned response.
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Harnett NG, Shumen JR, Wagle PA, Wood KH, Wheelock MD, Baños JH, Knight DC. Neural mechanisms of human temporal fear conditioning. Neurobiol Learn Mem 2016; 136:97-104. [PMID: 27693343 DOI: 10.1016/j.nlm.2016.09.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/20/2016] [Accepted: 09/26/2016] [Indexed: 01/21/2023]
Abstract
Learning the temporal relationship between a warning cue (conditioned stimulus; CS) and aversive threat (unconditioned stimulus; UCS) is an important aspect of Pavlovian conditioning. Although prior functional magnetic resonance imaging (fMRI) research has identified brain regions that support Pavlovian conditioning, it remains unclear whether these regions support time-related processes important for this type of associative learning. Elucidating the neural substrates of temporal conditioning is important for a complete understanding of the Pavlovian conditioning process. Therefore, the present study used a temporal Pavlovian conditioning procedure to investigate brain activity that mediates the formation of temporal associations. During fMRI, twenty-three healthy volunteers completed a temporal conditioning procedure and a control task that does not support conditioning. Specifically, during the temporal conditioning procedure, the UCS was presented at fixed intervals (ITI: 20s) while in the control condition the UCS was presented at random intervals (Average ITI: 20s, ITI Range: 6-34s). We observed greater skin conductance responses and expectancy of the UCS during fixed (i.e., temporal conditioning) relative to random (i.e., control procedure) interval trials. These findings demonstrate fixed trials support temporal conditioning, while random trials do not. During fixed interval trials, greater conditioned fMRI signal responses were observed within dorsolateral prefrontal cortex, inferior parietal lobule, inferior and middle temporal cortex, hippocampus, and amygdala. The current findings suggest these brain regions constitute a neural circuit that encodes the temporal information necessary for Pavlovian fear conditioning.
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Affiliation(s)
- Nathaniel G Harnett
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Joshua R Shumen
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Pooja A Wagle
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Kimberly H Wood
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Muriah D Wheelock
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - James H Baños
- Department of Medical Education, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - David C Knight
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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Individual Differences in Anticipatory Somatosensory Cortex Activity for Shock is Positively Related with Trait Anxiety and Multisensory Integration. Brain Sci 2016; 6:brainsci6010002. [PMID: 26751483 PMCID: PMC4810172 DOI: 10.3390/brainsci6010002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 12/14/2015] [Accepted: 12/18/2015] [Indexed: 12/27/2022] Open
Abstract
Anxiety is associated with an exaggerated expectancy of harm, including overestimation of how likely a conditioned stimulus (CS+) predicts a harmful unconditioned stimulus (US). In the current study we tested whether anxiety-associated expectancy of harm increases primary sensory cortex (S1) activity on non-reinforced (i.e., no shock) CS+ trials. Twenty healthy volunteers completed a differential-tone trace conditioning task while undergoing fMRI, with shock delivered to the left hand. We found a positive correlation between trait anxiety and activity in right, but not left, S1 during CS+ versus CS− conditions. Right S1 activity also correlated with individual differences in both primary auditory cortices (A1) and amygdala activity. Lastly, a seed-based functional connectivity analysis demonstrated that trial-wise S1 activity was positively correlated with regions of dorsolateral prefrontal cortex (dlPFC), suggesting that higher-order cognitive processes contribute to the anticipatory sensory reactivity. Our findings indicate that individual differences in trait anxiety relate to anticipatory reactivity for the US during associative learning. This anticipatory reactivity is also integrated along with emotion-related sensory signals into a brain network implicated in fear-conditioned responding.
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Mueller EM, Pizzagalli DA. One-year-old fear memories rapidly activate human fusiform gyrus. Soc Cogn Affect Neurosci 2015; 11:308-16. [PMID: 26416784 DOI: 10.1093/scan/nsv122] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 09/21/2015] [Indexed: 11/14/2022] Open
Abstract
Fast threat detection is crucial for survival. In line with such evolutionary pressure, threat-signaling fear-conditioned faces have been found to rapidly (<80 ms) activate visual brain regions including the fusiform gyrus on the conditioning day. Whether remotely fear conditioned stimuli (CS) evoke similar early processing enhancements is unknown. Here, 16 participants who underwent a differential face fear-conditioning and extinction procedure on day 1 were presented the initial CS 24 h after conditioning (Recent Recall Test) as well as 9-17 months later (Remote Recall Test) while EEG was recorded. Using a data-driven segmentation procedure of CS evoked event-related potentials, five distinct microstates were identified for both the recent and the remote memory test. To probe intracranial activity, EEG activity within each microstate was localized using low resolution electromagnetic tomography analysis (LORETA). In both the recent (41-55 and 150-191 ms) and remote (45-90 ms) recall tests, fear conditioned faces potentiated rapid activation in proximity of fusiform gyrus, even in participants unaware of the contingencies. These findings suggest that rapid processing enhancements of conditioned faces persist over time.
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Affiliation(s)
- Erik M Mueller
- Department of Clinical Psychology, Justus-Liebig University Giessen, 35394 Giessen, Germany and
| | - Diego A Pizzagalli
- Center for Depression, Anxiety and Stress Research & McLean Imaging Center, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA
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Sevenster D, Hamm A, Beckers T, Kindt M. Heart rate pattern and resting heart rate variability mediate individual differences in contextual anxiety and conditioned responses. Int J Psychophysiol 2015; 98:567-76. [PMID: 26393823 DOI: 10.1016/j.ijpsycho.2015.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 07/21/2015] [Accepted: 09/11/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Dieuwke Sevenster
- Laboratory of Biological Psychology, Department of Psychology, University of Leuven, Leuven, Belgium; Clinical Psychology, Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands; Amsterdam Brain and Cognition, Amsterdam, The Netherlands.
| | - Alfons Hamm
- Biological and Clinical Psychology, Department of Psychology, University of Greifswald, Greifswald, Germany
| | - Tom Beckers
- Clinical Psychology, Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands; Amsterdam Brain and Cognition, Amsterdam, The Netherlands; Centre for the Psychology of Learning and Experimental Psychopathology, Department of Psychology, University of Leuven, Leuven, Belgium
| | - Merel Kindt
- Clinical Psychology, Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands; Amsterdam Brain and Cognition, Amsterdam, The Netherlands
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Attention is necessary for subliminal instrumental conditioning. Sci Rep 2015; 5:12920. [PMID: 26257144 PMCID: PMC4530442 DOI: 10.1038/srep12920] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 07/02/2015] [Indexed: 11/24/2022] Open
Abstract
The capacity of humans and other animals to provide appropriate responses to stimuli anticipating motivationally significant events is exemplified by instrumental conditioning. Interestingly, in humans instrumental conditioning can occur also for subliminal outcome-predicting stimuli. However, it remains unclear whether attention is necessary for subliminal instrumental conditioning to take place. In two experiments, human participants had to learn to collect rewards (monetary gains) while avoiding punishments (monetary losses), on the basis of subliminal outcome-predicting cues. We found that instrumental conditioning can proceed subconsciously only if spatial attention is aligned with the subliminal cue. Conversely, if spatial attention is briefly diverted from the subliminal cue, then instrumental conditioning is blocked. In humans, attention but not awareness is therefore mandatory for instrumental conditioning, thus revealing a dissociation between awareness and attention in the control of motivated behavior.
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Pappens M, Vandenbossche E, Van den Bergh O, Van Diest I. Interoceptive fear learning to mild breathlessness as a laboratory model for unexpected panic attacks. Front Psychol 2015; 6:1150. [PMID: 26300830 PMCID: PMC4527095 DOI: 10.3389/fpsyg.2015.01150] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 07/23/2015] [Indexed: 11/13/2022] Open
Abstract
Fear learning is thought to play an important role in panic disorder. Benign interoceptive sensations can become predictors (conditioned stimuli - CSs) of massive fear when experienced in the context of an initial panic attack (unconditioned stimulus - US). The mere encounter of these CSs on a later moment can induce anxiety and fear, and precipitate a new panic attack. It has been suggested that fear learning to interoceptive cues would result in unpredictable panic. The present study aimed to investigate whether fear learning to an interoceptive CS is possible without declarative knowledge of the CS-US contingency. The CS consisted of mild breathlessness (or: dyspnea), the US was a suffocation experience. During acquisition, the experimental group received six presentations of mild breathlessness immediately followed by suffocation; for the control group both experiences were always separated by an intertrial interval. In the subsequent extinction phase, participants received six unreinforced presentations of the CS. Expectancy of the US was rated continuously and startle eyeblink electromyographic, skin conductance, and respiration were measured. Declarative knowledge of the CS-US relationship was also assessed with a post-experimental questionnaire. At the end of acquisition, both groups displayed the same levels of US expectancy and skin conductance in response to the CS, but the experimental group showed a fear potentiated startle eyeblink and a different respiratory response to the CS compared to the control group. Further analyses on a subgroup of CS-US unaware participants confirmed the presence of startle eyeblink conditioning in the experimental group but not in the control group. Our findings suggest that interoceptive fear learning is not dependent on declarative knowledge of the CS-US relationship. The present interoceptive fear conditioning paradigm may serve as an ecologically valid laboratory model for unexpected panic attacks.
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Affiliation(s)
- Meike Pappens
- Health Psychology, University of Leuven Leuven, Belgium
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Classical conditioning of analgesic and hyperalgesic pain responses without conscious awareness. Proc Natl Acad Sci U S A 2015; 112:7863-7. [PMID: 25979940 DOI: 10.1073/pnas.1504567112] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pain reduction and enhancement can be produced by means of conditioning procedures, yet the role of awareness during the acquisition stage of classical conditioning is unknown. We used psychophysical measures to establish whether conditioned analgesic and hyperalgesic responses could be acquired by unseen (subliminally presented) stimuli. A 2 × 2 factorial design, including subliminal/supraliminal exposures of conditioning stimuli (CS) during acquisition/extinction, was used. Results showed significant analgesic and hyperalgesic responses (P < 0.001), and responses were independent of CS awareness, as subliminal/supraliminal cues during acquisition/extinction led to comparable outcomes. The effect was significantly larger for hyperalgesic than analgesic responses (P < 0.001). Results demonstrate that conscious awareness of the CS is not required during either acquisition or extinction of conditioned analgesia or hyperalgesia. Our results support the notion that nonconscious stimuli have a pervasive effect on human brain function and behavior and may affect learning of complex cognitive processes such as psychologically mediated analgesic and hyperalgesic responses.
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Packard PA, Rodríguez-Fornells A, Stein LM, Nicolás B, Fuentemilla L. Tracking explicit and implicit long-lasting traces of fearful memories in humans. Neurobiol Learn Mem 2014; 116:96-104. [PMID: 25256154 DOI: 10.1016/j.nlm.2014.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 12/27/2022]
Abstract
Recent accounts of Posttraumatic Stress Disorder (PTSD) suggest that the encoding of an episode within a fearful context generates different implicit and explicit memory representations. Whilst implicit memory traces include the associated emotional states, explicit traces include a recoding into an abstract or gist-based structural context of the episode. Theoretically, the long-term preservation of implicit memory traces may facilitate the often untreatable memory intrusions in PTSD. Here, we tracked in two experiments how implicit and explicit memory traces for fearful episodes dissociate and evolve over time. Subjects (N=86) were presented with semantically-related word-lists in a contextual fear paradigm and tested for explicit memories either immediately (i.e., 30 min) or after a delay (i.e., 1 or 2 weeks) with a verbal recognition task. Skin Conductance Response (SCR) was used to assess implicit memory responses. Subjects showed high memory accuracy for words when tested immediately after encoding. At test, SCR was higher during the presentation of verbatim but not gist-based words encoded in a fearful context, and remained unchanged after 2 weeks, despite subjects being unaware of words' encoding context. We found no clear evidence of accurate explicit memory traces for the fearful or neutral contexts of words presented during encoding, either 30 min or 2 weeks afterwards. These findings indicate that the implicit, but not the explicit, memory trace of a fearful context of an episode can be detected at long-term through SCR and is dissociated from the gist-based memory. They may have implicationstowards the understanding of how the processing of fearful memoriescould lead to PTSD.
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Affiliation(s)
- Pau Alexander Packard
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain; Department of Basic Psychology, University of Barcelona, Barcelona, Spain.
| | - Antoni Rodríguez-Fornells
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain; Department of Basic Psychology, University of Barcelona, Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | | | - Berta Nicolás
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Lluís Fuentemilla
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain; Department of Basic Psychology, University of Barcelona, Barcelona, Spain
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39
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Mudrik L, Faivre N, Koch C. Information integration without awareness. Trends Cogn Sci 2014; 18:488-96. [DOI: 10.1016/j.tics.2014.04.009] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 03/10/2014] [Accepted: 04/21/2014] [Indexed: 10/25/2022]
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Zeng XX, Du J, Zhuang CQ, Zhang JH, Jia YL, Zheng XF. Unconditioned stimulus revaluation to promote conditioned fear extinction in the memory reconsolidation window. PLoS One 2014; 9:e101589. [PMID: 25033450 PMCID: PMC4102463 DOI: 10.1371/journal.pone.0101589] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/23/2014] [Indexed: 01/10/2023] Open
Abstract
The retrieval-extinction paradigm, which disrupts the reconsolidation of fear memories in humans, is a non-invasive technique that can be used to prevent the return of fear in humans. In the present study, unconditioned stimulus revaluation was applied in the retrieval-extinction paradigm to investigate its promotion of conditioned fear extinction in the memory reconsolidation window after participants acquired conditioned fear. This experiment comprised three stages (acquisition, unconditioned stimulus revaluation, retrieval-extinction) and three methods for indexing fear (unconditioned stimulus expectancy, skin conductance response, conditioned stimulus pleasure rating). After the acquisition phase, we decreased the intensity of the unconditioned stimulus in one group (devaluation) and maintained constant for the other group (control). The results indicated that both groups exhibited similar levels of unconditioned stimulus expectancy, but the devaluation group had significantly smaller skin conductance responses and exhibited a growth in conditioned stimulus + pleasure. Thus, our findings indicate unconditioned stimulus revaluation effectively promoted the extinction of conditioned fear within the memory reconsolidation window.
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Affiliation(s)
- Xiang-Xing Zeng
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Health Service Centers in Communities, South China Normal University, Guangzhou, China
| | - Juan Du
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Health Service Centers in Communities, South China Normal University, Guangzhou, China
| | - Chu-Qun Zhuang
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Health Service Centers in Communities, South China Normal University, Guangzhou, China
| | - Jun-Hua Zhang
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Health Service Centers in Communities, South China Normal University, Guangzhou, China
| | - Yan-Lei Jia
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Health Service Centers in Communities, South China Normal University, Guangzhou, China
| | - Xi-Fu Zheng
- Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
- Health Service Centers in Communities, South China Normal University, Guangzhou, China
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Dissociable roles for hippocampal and amygdalar volume in human fear conditioning. Brain Struct Funct 2014; 220:2575-86. [PMID: 24903827 DOI: 10.1007/s00429-014-0807-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 05/20/2014] [Indexed: 10/25/2022]
Abstract
Fear conditioning is a basic learning process which involves the association of a formerly neutral conditioned stimulus (CS) with a biologically relevant aversive unconditioned stimulus (US). Previous studies conducted in brain-lesioned patients have shown that while the acquisition of autonomic fear responses requires an intact amygdala, a spared hippocampus is necessary for the development of the CS-US contingency awareness. Although these data have been supported by studies using functional neuroimaging techniques in healthy people, attempts to extend these findings to the morphological aspects of amygdala and hippocampus are missing. Here we tested the hypothesis that amygdalar and hippocampal volumes play dissociable roles in determining autonomic responses and contingency awareness during fear conditioning. Fifty-two healthy individuals (mean age 21.83) underwent high-resolution magnetic resonance imaging. We used a differential delay fear conditioning paradigm while assessing skin conductance responses (SCRs), subjective ratings of CS-US contingency, as well as emotional valence and perceived arousal. Left amygdalar volume significantly predicted the magnitude of differential SCRs during fear acquisition, but had no impact on contingency learning. Conversely, bilateral hippocampal volumes were significantly related to contingency ratings, but not to SCRs. Moreover, left amygdalar volume predicted SCRs to the reinforced CS alone, but not those elicited by the US. Our findings bridge the gap between previous lesion and functional imaging studies, by showing that amygdalar and hippocampal volumes differentially modulate the acquisition of conditioned fear. Further, our results reveal that the morphology of these limbic structures moderate learning and memory already in healthy persons.
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Sevenster D, Beckers T, Kindt M. Fear conditioning of SCR but not the startle reflex requires conscious discrimination of threat and safety. Front Behav Neurosci 2014; 8:32. [PMID: 24616672 PMCID: PMC3937874 DOI: 10.3389/fnbeh.2014.00032] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 01/21/2014] [Indexed: 12/02/2022] Open
Abstract
There is conflicting evidence as to whether awareness is required for conditioning of the skin conductance response (SCR). Recently, Schultz and Helmstetter (2010) reported SCR conditioning in contingency unaware participants by using difficult to discriminate stimuli. These findings are in stark contrast with other observations in human fear conditioning research, showing that SCR predominantly reflects contingency learning. Therefore, we repeated the study by Schultz and Helmstetter and additionally measured conditioning of the startle response, which seems to be less sensitive to declarative knowledge than SCR. While we solely observed SCR conditioning in participants who reported awareness of the contingencies (n = 16) and not in the unaware participants (n = 18), we observed startle conditioning irrespective of awareness. We conclude that SCR but not startle conditioning depends on conscious discriminative fear learning.
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Affiliation(s)
- Dieuwke Sevenster
- Department of Clinical Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam Amsterdam, Netherlands ; Amsterdam Brain and Cognition, University of Amsterdam Amsterdam, Netherlands
| | - Tom Beckers
- Department of Clinical Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam Amsterdam, Netherlands ; Amsterdam Brain and Cognition, University of Amsterdam Amsterdam, Netherlands ; Faculty of Psychology and Educational Sciences, Department of Psychology, University of Leuven Leuven, Belgium
| | - Merel Kindt
- Department of Clinical Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam Amsterdam, Netherlands ; Amsterdam Brain and Cognition, University of Amsterdam Amsterdam, Netherlands
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Meuwese JDI, Post RAG, Scholte HS, Lamme VAF. Does Perceptual Learning Require Consciousness or Attention? J Cogn Neurosci 2013; 25:1579-96. [PMID: 23691987 DOI: 10.1162/jocn_a_00424] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
It has been proposed that visual attention and consciousness are separate [Koch, C., & Tsuchiya, N. Attention and consciousness: Two distinct brain processes. Trends in Cognitive Sciences, 11, 16–22, 2007] and possibly even orthogonal processes [Lamme, V. A. F. Why visual attention and awareness are different. Trends in Cognitive Sciences, 7, 12–18, 2003]. Attention and consciousness converge when conscious visual percepts are attended and hence become available for conscious report. In such a view, a lack of reportability can have two causes: the absence of attention or the absence of a conscious percept. This raises an important question in the field of perceptual learning. It is known that learning can occur in the absence of reportability [Gutnisky, D. A., Hansen, B. J., Iliescu, B. F., & Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19, 555–560, 2009; Seitz, A. R., Kim, D., & Watanabe, T. Rewards evoke learning of unconsciously processed visual stimuli in adult humans. Neuron, 61, 700–707, 2009; Seitz, A. R., & Watanabe, T. Is subliminal learning really passive? Nature, 422, 36, 2003; Watanabe, T., Náñez, J. E., & Sasaki, Y. Perceptual learning without perception. Nature, 413, 844–848, 2001], but it is unclear which of the two ingredients—consciousness or attention—is not necessary for learning. We presented textured figure-ground stimuli and manipulated reportability either by masking (which only interferes with consciousness) or with an inattention paradigm (which only interferes with attention). During the second session (24 hr later), learning was assessed neurally and behaviorally, via differences in figure-ground ERPs and via a detection task. Behavioral and neural learning effects were found for stimuli presented in the inattention paradigm and not for masked stimuli. Interestingly, the behavioral learning effect only became apparent when performance feedback was given on the task to measure learning, suggesting that the memory trace that is formed during inattention is latent until accessed. The results suggest that learning requires consciousness, and not attention, and further strengthen the idea that consciousness is separate from attention.
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Affiliation(s)
- Julia D I Meuwese
- Department of Psychology, University of Amsterdam, Amsterdam, Netherlands.
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Andreatta M, Mühlberger A, Glotzbach-Schoon E, Pauli P. Pain predictability reverses valence ratings of a relief-associated stimulus. Front Syst Neurosci 2013; 7:53. [PMID: 24068989 PMCID: PMC3782145 DOI: 10.3389/fnsys.2013.00053] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 08/30/2013] [Indexed: 11/16/2022] Open
Abstract
Relief from pain is positively valenced and entails reward-like properties. Notably, stimuli that became associated with pain relief elicit reward-like implicit responses too, but are explicitly evaluated by humans as aversive. Since the unpredictability of pain makes pain more aversive, this study examined the hypotheses that the predictability of pain also modulates the valence of relief-associated stimuli. In two studies, we presented one conditioned stimulus (FORWARDCS+) before a painful unconditioned stimulus (US), another stimulus (BACKWARDCS+) after the painful US, and a third stimulus (CS−) was never associated with the US. In Study 1, FORWARDCS+ predicted half of the USs while the other half was delivered unwarned and followed by BACKWARDCS+. In Study 2, all USs were predicted by FORWARDCS+ and followed by BACKWARDCS+. In Study 1 both FORWARDCS+ and BACKWARDCS+ were rated as negatively valenced and high arousing after conditioning, while BACKWARDCS+ in Study 2 acquired positive valence and low arousal. Startle amplitude was significantly attenuated to BACKWARDCS+ compared to FORWARDCS+ in Study 2, but did not differ among CSs in Study 1. In summary, predictability of aversive events reverses the explicit valence of a relief-associated stimulus.
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Affiliation(s)
- Marta Andreatta
- Department of Psychology (Biological Psychology, Clinical Psychology and Psychotherapy), University of Würzburg Würzburg, Germany
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Schultz DH, Balderston NL, Geiger JA, Helmstetter FJ. Dissociation between implicit and explicit responses in postconditioning UCS revaluation after fear conditioning in humans. Behav Neurosci 2013; 127:357-68. [PMID: 23731073 PMCID: PMC3959889 DOI: 10.1037/a0032742] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The nature of the relationship between explicit and implicit learning is a topic of considerable debate. To investigate this relationship we conducted two experiments on postconditioning revaluation of the unconditional stimulus (UCS) in human fear conditioning. In Experiment 1, the intensity of the UCS was decreased after acquisition for one group (devaluation) and held constant for another group (control). A subsequent test revealed that even though both groups exhibited similar levels of UCS expectancy, the devaluation group had significantly smaller conditional skin conductance responses. The devaluation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. In Experiment 2, the value of the UCS was increased after acquisition for one group (inflation) and held constant for another group (control). Test performance revealed that UCS inflation did not alter expectancy ratings, but the inflation group exhibited larger learned skin conductance responses than the control group. The inflation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. The SCR revaluation effect was not dependent on explicit memory processes in either experiment. In both experiments we found differences on an implicit measure of learning in the absence of changes in explicit measures. Together, the differences observed between expectancy measures and skin conductance support the idea that these responses might reflect different types of memory formed during the same training procedure and be supported by separate neural systems.
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Affiliation(s)
- Douglas H Schultz
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
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47
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Singh K, Dawson ME, Schell AM, Courtney CG, Payne AF. Can human autonomic classical conditioning occur without contingency awareness? The critical importance of the trial sequence. Biol Psychol 2013; 93:197-205. [DOI: 10.1016/j.biopsycho.2013.02.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 02/01/2013] [Accepted: 02/02/2013] [Indexed: 11/25/2022]
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Hindi Attar C, Finckh B, Büchel C. The influence of serotonin on fear learning. PLoS One 2012; 7:e42397. [PMID: 22879964 PMCID: PMC3411733 DOI: 10.1371/journal.pone.0042397] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/04/2012] [Indexed: 11/18/2022] Open
Abstract
Learning of associations between aversive stimuli and predictive cues is the basis of Pavlovian fear conditioning and is driven by a mismatch between expectation and outcome. To investigate whether serotonin modulates the formation of such aversive cue-outcome associations, we used functional magnetic resonance imaging (fMRI) and dietary tryptophan depletion to reduce brain serotonin (5-HT) levels in healthy human subjects. In a Pavlovian fear conditioning paradigm, 5-HT depleted subjects compared to a non-depleted control group exhibited attenuated autonomic responses to cues indicating the upcoming of an aversive event. These results were closely paralleled by reduced aversive learning signals in the amygdala and the orbitofrontal cortex, two prominent structures of the neural fear circuit. In agreement with current theories of serotonin as a motivational opponent system to dopamine in fear learning, our data provide first empirical evidence for a role of serotonin in representing formally derived learning signals for aversive events.
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Affiliation(s)
- Catherine Hindi Attar
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Gawronski B, Walther E. What do memory data tell us about the role of contingency awareness in evaluative conditioning? JOURNAL OF EXPERIMENTAL SOCIAL PSYCHOLOGY 2012. [DOI: 10.1016/j.jesp.2012.01.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Wood KH, Ver Hoef LW, Knight DC. Neural mechanisms underlying the conditioned diminution of the unconditioned fear response. Neuroimage 2012; 60:787-99. [DOI: 10.1016/j.neuroimage.2011.12.048] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 12/15/2011] [Accepted: 12/17/2011] [Indexed: 10/14/2022] Open
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