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BackgroundFear is an evolutionary adaptive emotion that serves to protect the organism from harm. Once a threat diminishes, fear should also dissipate as otherwise fear may become chronic and pathological. While actual threat of the COVID-19 pandemic (i.e., number of infections, hospitalizations, and deaths) has substantially varied over the course of the pandemic, it remains unclear whether (subjective) fear has followed a similar pattern.MethodTo examine the development of fear of COVID-19 during the pandemic and investigate potential predictors of chronic fear, we conducted a large online longitudinal study (N = 2000) using the Prolific platform between April 2020 and June 2021. Participants were voluntary response samples and consisted of residents of 34 different countries. The Fear of the Coronavirus Questionnaire (FCQ) and several other demographic and psychological measures were completed monthly.ResultsOverall, we find that fear steadily decreased since April 2020. Additional analyses showed that elevated fear was predicted by region (i.e., North America > Europe), anxious traits, gender, risks for loved ones, general health, and media use.LimitationsThe interpretation of the results of this study is limited by the non-representativeness of the sample and the lack of data points between August 2020 and June 2021.ConclusionsThis study helps to characterize the trajectory of fear levels throughout the COVID-19 pandemic and establish several relevant predictors of increased fear.

Fear is an emotion triggered by the perception of danger and is a motivator for safety behaviors, including hygienic ones. Within the context of the coronavirus disease-2019 (COVID-19) pandemic, there were ample danger cues (e.g., images of patients on ventilators) and a high need for people to use appropriate safety behaviors (e.g., social distancing). Given this central role of fear within the context of a pandemic, it is important to review some of the emerging findings and lessons learned to manage fear during the COVID-19 pandemic. Particularly, in the current paper, we highlight different factors that determine fear (i.e., proximity, predictability, and controllability), we review several adaptive and maladaptive consequences of fear of COVID-19 (e.g., following governmental health policies and panic buying), and we make recommendations for policies that can promote adequate health behaviors and limit negative consequences of fear during pandemics.

Fear of the unknown is considered a primary, fundamental fear (Carleton, 2016a, Carleton, 2016b; Papenfuss and Ostafin, 2021). In research settings, the fear of the unknown is commonly captured using the self-reported Intolerance of Uncertainty Scale (Carleton et al., 2007; Freeston et al., 1994), which measures the tendency to interpret and react to uncertainty negatively. Importantly, recent research has demonstrated that high levels of self-reported intolerance of uncertainty exist across many emotional disorders (e.g. anxiety, depression, stress and trauma, and obsessive-compulsive disorders) (McEvoy et al., 2019). Moreover, emerging research demonstrates that high levels of self-reported intolerance of uncertainty can be reduced to some extent through short-term interventions in the general population (Dunsmoor et al., 2015; Li et al., 2021; Morriss et al., 2020; Oglesby et al., 2017; Wake et al., 2021), and longer-term transdiagnostic (Sperling, 2022; Talkovsky and Norton, 2016), general (McEvoy and Erceg-Hurn, 2016; Palitz et al., 2019), and intolerance of uncertainty-specific (Dugas et al., 2022; Hebert and Dugas, 2019; Mofrad et al., 2020) standardised treatment protocols (e.g., cognitive behavioural therapy) in clinical populations. Given this progress, there is an increasing need for research examining the neural and psychophysiological basis of intolerance of uncertainty (Morriss et al., 2021; Tanovic et al., 2018), in order to enhance our mechanistic understanding of how intolerance of uncertainty modulates key processes relevant to the pathogenesis and treatment of emotional disorders (Einstein, 2014; Grupe and Nitschke, 2013; Hong and Cheung, 2015; Paulus et al., 2015; Shihata et al., 2016).

Preregistration of research plans is becoming an increasingly popular and common tool to enhance the transparency of a study’s methodology. In a preregistration, researchers document their research plans and register them to a public repository prior to conducting their research. In this chapter, we provide arguments for why preregistration can protect scientific findings against Questionable Research Practices (QRPs), such as outcome swapping, selective reporting of conditions, unwarranted data exclusions, and post-hoc changing of hypotheses. Furthermore, we place particular emphasis on preregistering research plans when using existing data and we give an overview of preregistration templates and public repositories for different types of research designs. We conclude this chapter with highlighting some of the common criticisms of preregistration and our counter-arguments, and provide future reflections.

{PREPRINT} Questionable Research Practices (QRPs), such as p-hacking (i.e., the inappropriate manipulation of data analysis to find statistical significance) and post-hoc hypothesizing, are threats to replicability of research findings. One key solution to the problem of QRPs is pre- registration. This refers to time-stamped documentation that describes the methodology and statistical analyses of a study before the data are collected or inspected. As such, readers of the study’s report can evaluate whether the described research is in line with the planned methods and analyses or there are deviations from these (e.g., analyses performed so that the research hypotheses is confirmed). Here, we aim to describe what preregistration entails and why it is useful for psychology research. In this vein, we present the key elements of a sufficient preregistration file, its advantages, as well as its disadvantages, and why preregistration is a key, yet partially insufficient, solution against QRPs. By the end of this chapter, we hope that readers are convinced that there is little reason not to preregister their research.

Dual-learning theories of evaluations posit that evaluations can be automatically (i.e., efficiently, unconsciously, uncontrollably, and involuntarily) acquired. They also often assume the existence of evaluative-learning processes that are impervious to verbal information. In this article, we explain that recent research challenges both assertions for three categories of measures: explicit evaluative measures, implicit evaluative measures, and physiological measures of fear. In doing so, we also question the widespread assumption that implicit (i.e., typically behavioral and physiological) compared with explicit (i.e., self-reported) evaluative measures are indicative of the way evaluations are acquired. In the second part of the article, we discuss the practical implications of these recent findings.

Vaccines are an important tool for governments and health agencies to contain and curb the Coronavirus Disease-19 (COVID-19) pandemic. However, despite their effectiveness and safeness, a substantial portion of the population worldwide is hesitant to get vaccinated. In the current study, we examined whether fear of COVID-19 predicts vaccination willingness. In a longitudinal study (N = 938), fear for COVID-19 was assessed in April 2020 and vaccination willingness was measured in June 2021. Approximately 11% of our sample indicated that they were not willing to get vaccinated. Results of a logistic regression showed that increased fear of COVID-19 predicts vaccination willingness 14 months later, even when controlling for several anxious personality traits, infection control perceptions, risks for loved ones, self-rated health, previous infection, media use, and demographic variables. These results show that fear of COVID-19 is a relevant construct to consider for predicting and possibly influencing vaccination willingness. Nonetheless, sensitivity and specificity of fear of COVID-19 to predict vaccination willingness were quite low and only became slightly better when fear of COVID-19 was measured concurrently. This indicates that other potential factors, such as perceived risks of the vaccines, probably also play a role in explaining vaccination willingness.

The authors regret to inform that an error was made in the data analysis syntax for the analyses reported in the referenced article. Particularly, we included the “Behavioral Inhibition Scale” (BIS) in this study and correlated the scores on this questionnaire to generalization gradients in a fear generalization paradigm. Accidentally, we used items from the Intolerance of Uncertainty Scale (IUS), rather than the BIS, to calculate the BIS total scores. As a result of this error, the average BIS total score and the correlations that we report in Table 1 of the original article with this scale are incorrect. We report the correct BIS total score, standard deviation, and correlations with this scale in the updated table below (Table 1). Please note that, using the correct BIS scores, the correlation between the Generalization Index (GI) for fear potentiated startle (FPS) and BIS (r = −0.19; p = .037) now reached the conventional alpha cut-off level for statistical significance (0.05). However, this correlation was not significant according to our adjusted alpha level (0.017) that we had pre-specified for our study. As such, all the main conclusions of the original article remain unchanged. The authors would like to apologise for any inconvenience caused.

The COVID-19 pandemic has a substantial impact on mental health. Prior reports have shown that depression, anxiety, and stress have increased throughout the pandemic. Nonetheless, not everyone is affected by these negative consequences and some people may be relatively unaffected. In this online study in a predominantly Dutch and Belgian sample (N = 546), we investigated whether positive personality traits such as optimism, mindfulness, and resilience may protect against the negative mental health consequences (i.e., fear of the coronavirus, depression, stress, and anxiety) of the COVID-19 pandemic. We found that fear of COVID-19 was related to higher depression, stress, and anxiety. However, for participants scoring high on mindfulness, optimism, and resilience, this relationship was weakened. In addition to these findings, we present the results of network analyses to explore the network structure between these constructs. These results help to identify possible ways through which psychological well-being can be promoted during the COVID-19 pandemic.

Background: As for many psychotherapies, there is ongoing discussion about the role of specific versus unspecific mechanisms in the effectiveness of Eye-Movement and Desensitization Reprocessing (EMDR) therapy for post-traumatic stress disorder. However, research directly examining the potential role of non-specific mechanisms in EMDR is scarce. Objectives: Here, we address the role of one non-specific factor that is often put forward, namely treatment effectiveness expectations, in a laboratory model of EMDR therapy. Method: In a lab-based study (N = 96) and an online study (N = 173), we gave participants verbal instructions to manipulate their treatment expectations. Instructions emphasized EMDR’s effectiveness or infectiveness. Then, participants were asked to recollect an unpleasant autobiographical memory with or without making eye-movements. Results: In line with previous studies, we found significant reductions of reported vividness and emotionality of negative autobiographical memories. However, this effect was not modulated by manipulated treatment efficacy expectations. It must be noted that manipulation checks indicated that it was difficult to influence treatment effectiveness expectations using verbal suggestions. Conclusions: These findings corroborate the results of two earlier reports, suggesting that the role of treatment expectations in EMDR therapy may be limited.

The ability to update responding to threat cues is an important adaptive ability. Recently, Morriss et al. (2019) demonstrated that participants scoring high in Intolerance of Uncertainty (IU) were more capable of threat reversal. The current report aimed to conceptually replicate these results of Morriss et al. (2019) in an independent sample using a comparable paradigm (n = 102). Following a threat conditioning phase, participants were told that cues associated with threat and safety from electric shock would reverse. Responding was measured with skin conductance and fear potentiated startle. We failed to conceptually replicate the results of Morriss et al. (2019). Instead, we found that, for participants who received precise contingency instructions prior to acquisition, lower IUS (controlling for STAI-T) relative to higher IUS was associated with greater threat reversal, indexed via skin conductance responses. These results suggest that IU and contingency instructions differentially modulate the course of threat reversal.

Human fear conditioning is often seen as the result of a highly automatic process that is independent of higher cognitive functions and verbal instructions. However, cumulative research findings call this view into question. In the current preregistered study (N = 102), we investigated whether the number of participants who successfully show conditioned fear acquisition depends on the instructions given to them before the fear conditioning phase. Particularly, one third of the participants were instructed about the precise contingency between the conditioned stimulus (CS) and unconditioned stimulus (US). Another third was merely instructed that there would be a contingency. The last third did not get any instructions about the CS-US contingency. We found facilitated fear acquisition rate in the first and second group compared to the third group. Furthermore, contingency reversal instructions following the acquisition phase reversed both conditioned skin conductance and startle responses. These results highlight that researchers should systematically report the instructions given to participants in human fear conditioning studies.

Fear learning reflects the adaptive ability to learn to anticipate aversive events and to display preparatory fear reactions based on prior experiences. Usually, these learning experiences are modeled in the lab with pairings between a neutral conditioned stimulus (CS) and an aversive unconditioned stimulus (US) (i.e., fear conditioning via CS-US pairings). Nevertheless, for humans, fear learning can also be based on verbal instructions. In this review, we consider the role of verbal instructions in laboratory fear learning. Specifically, we consider both the effects of verbal instructions on fear responses in the absence of CS-US pairings as well as the way in which verbal instructions moderate fear established via CS-US pairings. We first focus on the available empirical findings about both types of effects. More specifically, we consider how these effects are moderated by elements of the fear conditioning procedure (i.e., the stimuli, the outcome measures, the relationship between the stimuli, the participants, and the broader context). Thereafter, we discuss how well different mental-process models of fear learning account for these empirical findings. Finally, we conclude the review with a discussion of open questions and opportunities for future research. ispartof: BIOLOGICAL PSYCHOLOGY vol:137 pages:49-64 ispartof: location:Netherlands status: published

For decades already, the human fear conditioning paradigm has been used to study and develop treatments for anxiety disorders. This research is guided by theoretical assumptions that, in some cases indirectly, stem from the tradition of association formation models (e.g., the Rescorla-Wagner model). We argue that one of these assumptions – fear responding as a monotonic function of the associative activation of aversive memory representations – restricts the types of treatment that the research community currently considers. We discuss the importance of this assumption in the context of research on extinction-enhancing and reconsolidation interference techniques. While acknowledging the merit of this research, we argue that unstrapping the straitjacket of this assumption can lead to exploring new directions for utilizing fear conditioning procedures in treatment research. We discuss two determinants of fear responding other than associative memory activation. First, fear responding might also depend on relational information. Second, a recent goal-directed emotion theory suggests that goals might be the primary determinant of the response pattern characterized as fear. ispartof: Neuroscience And Biobehavioral Reviews vol:112 pages:410-419 ispartof: location:United States status: published

Whether fear conditioning can take place without contingency awareness is a topic of continuing debate and conflicting findings have been reported in the literature. This systematic review provides a critical assessment of the available evidence. Specifically, a search was conducted to identify articles reporting fear conditioning studies in which the contingency between conditioned stimuli (CS) and the unconditioned stimulus (US) was masked, and in which CS-US contingency awareness was assessed. A systematic assessment of the methodological quality of the included studies (k = 41) indicated that most studies suffered from methodological limitations (i.e., poor masking procedures, poor awareness measures, researcher degrees of freedom, and trial-order effects), and that higher quality predicted lower odds of studies concluding in favor of contingency unaware fear conditioning. Furthermore, meta-analytic moderation analyses indicated no evidence for a specific set of conditions under which contingency unaware fear conditioning can be observed. Finally, funnel plot asymmetry and p-curve analysis indicated evidence for publication bias. We conclude that there is no convincing evidence for contingency unaware fear conditioning.

A hallmark symptom of fear and anxiety disorder is generalization of fear to essentially innocuous stimuli and situations. Such generalization can occur through both perceptual and conceptually similarities. Recent studies indicate that perceptual generalization is inflated in anxiety patients and individuals prone to develop anxiety disorders, suggesting that perceptual generalization may be involved in the etiology of anxiety disorders. In the current study we want to address whether conceptual generalization is potentially implicated in the development of anxiety disorders. Therefore, we will use a novel paradigm in which the Dutch word mini [tiny] or enorm [enormous] is paired with an electric shock and assess fear to the conceptually related words klein [small], medium [medium], and groot [large]. The obtained generalization gradients will be related to personality traits known to be vulnerability factors for anxiety disorders. These results will provide insight into conceptual fear generalization and whether this phenomenon potentially relates to the development of anxiety disorders.

Since the outbreak of the coronavirus disease (COVID-19), several reports have shown that fear relating to COVID-19 has sharply increased. To measure fear of COVID-19, various questionnaires have been developed in parallel. However, fear concerning COVID-19 is not necessarily a uniform construct and the different questionnaires may cover diverse aspects. To examine the underlying structure of fear of COVID-19, we conducted structural equation modelling and network analyses on four scales in an online convenience sample (N = 829). Particularly, the Fear of COVID-19 Scale (Ahorsu et al., 2020), the Fear of the Coronavirus Questionnaire (Mertens et al., 2020), and the COVID Stress Scales (Taylor, Landry, Paluszek, Fergus et al., 2020, Taylor, Landry, Paluszek, Rachor et al., 2020) were included in our study, along with a new scale that also assessed socio-economic worries relating to COVID-19. We found that fear of COVID-19 was best classified into four clusters: Fear of health-related consequences, fear of supplies shortages and xenophobia, fear about socio-economic consequences, and symptoms of fear (e.g., compulsions, nightmares). We also find that a central cluster of items centered on fear of health, which likely represents the core of fear of COVID-19. These results help to characterize fear due to COVID-19 and inform future research.

We investigated whether stimuli merely instructed to be fear-relevant can bias visual attention, even when the fear relation was never experienced before. Participants performed a dot-probe task with pictures of naturally fear-relevant (snake or spider) or -irrelevant (bird or butterfly) stimuli. Instructions indicated that two pictures (one naturally fear-relevant and one fear-irrelevant) could be followed by an electrical stimulation (i.e., instructed fear). In reality, no stimulation was administered. During the task, two pictures were presented on each side of the screen, after which participants had to determine as fast as possible on which side a black dot appeared. After a first phase, fear was reinstated by instructing participants that the device was not connected but now was (reinstatement phase). Participants were faster when the dot appeared on a location where an instructed fear picture was presented. This effect seemed independent of whether picture content was naturally fear-relevant, but was only found in the first half of each phase, suggesting rapid extinction due to the absence of stimulation, and rapid re-evaluation after reinstatement. A second experiment similarly showed that instructed fear biases attention, even when participants were explicitly instructed that no stimulation would be given during the dot-probe task. Together, these findings demonstrate that attention can be biased towards instructed fear stimuli, even when these fear relations were never experienced. Future studies should test whether this is specific to fear, or can be observed for all instructions that change the relevance of a given stimulus.

The mere exposure effect refers to the well-established finding that people evaluate a stimulus more positively after repeated exposure to that stimulus. We investigated whether a change in stimulus evaluation can occur also when participants are not repeatedly exposed to a stimulus, but are merely instructed that one stimulus will occur frequently and another stimulus will occur infrequently. We report seven experiments showing that (1) mere exposure instructions influence implicit stimulus evaluations as measured with an Implicit Association Test (IAT), personalized Implicit Association Test (pIAT), or Affect Misattribution Procedure (AMP), but not with an Evaluative Priming Task (EPT), (2) mere exposure instructions influence explicit evaluations, and (3) the instruction effect depends on participants' memory of which stimulus will be presented more frequently. We discuss how these findings inform us about the boundary conditions of mere exposure instruction effects, as well as the mental processes that underlie mere exposure and mere exposure instruction effects.

Whereas it is widely recognized that both verbal threat information and stimulus pairings can install strong and persistent fear, few studies have addressed the interaction between these two pathways of fear. According to the expectancy bias of Davey (1992, 1997), verbal information can install expectancy biases for aversive events that can result in facilitated fear learning through stimulus pairings and can delay extinction of fear. However, these predictions of the expectancy bias account have not been explored fully. Following up on two earlier studies (Field & Storksen-Coulson, 2007; Ugland, Dyson, & Field, 2013), we investigated the impact of prior threat information on fear acquisition, extinction and reinstatement. To this aim, participants received instructions about four unfamiliar animals, two of which that were described as dangerous whereas the other two were described as harmless. One animal of each pair was subsequently paired with an electric stimulus. Our results indicated that threat information resulted in stronger fear responses prior to fear conditioning and in delayed extinction of fear. However, these effects of instructions were not very pronounced and not found on all measures of fear. We discuss several methodological and procedural considerations that may modulate the effects of (verbally installed) expectancy biases.

Abstract. The mere exposure effect refers to the well-established finding that people evaluate a stimulus more positively after repeated exposure to that stimulus. We investigated whether a change in stimulus evaluation can occur also when participants are not repeatedly exposed to a stimulus, but are merely instructed that one stimulus will occur frequently and another stimulus will occur infrequently. We report seven experiments showing that (1) mere exposure instructions influence implicit stimulus evaluations as measured with an Implicit Association Test (IAT), personalized Implicit Association Test (pIAT), or Affect Misattribution Procedure (AMP), but not with an Evaluative Priming Task (EPT), (2) mere exposure instructions influence explicit evaluations, and (3) the instruction effect depends on participants’ memory of which stimulus will be presented more frequently. We discuss how these findings inform us about the boundary conditions of mere exposure instruction effects, as well as the mental processes that underlie mere exposure and mere exposure instruction effects.

Current treatments for anxiety disorders are effective but limited by the high frequency of clinical relapse. Processes underlying relapse are thought to be experimentally modeled in fear conditioning experiments with return fear (ROF) inductions. Thereby reinstatement-induced ROF might be considered a model to study mechanisms underlying adversity-induced relapse. Previous studies have reported differential ROF (i.e. specific for the danger stimulus) but also generalized ROF (i.e. for safe and danger stimuli), but reasons for these divergent findings are not clear yet. Hence, the response pattern (i.e. differential or generalized) following reinstatement may be of importance for the prediction of risk or resilience for ROF. The aim of this study was to investigate state anxiety as a potential individual difference factor contributing to differentiability or generalization of return of fear. Thirty-six participants underwent instructed fear expression, extinction and ROF induction through reinstatement while physiological (skin conductance response, fear potentiated startle) and subjective measures of fear and US expectancy were acquired. Our data show that, as expected, high state anxious individuals show deficits in SCR discrimination between dangerous and safe cues after reinstatement induced ROF (i.e. generalization) as compared to low state anxious individuals. The ability to maintain discrimination under aversive circumstances is negatively associated with pathological anxiety and predictive of resilient responding while excessive generalization is a hallmark of anxiety disorders. Therefore, we suggest that experimentally induced ROF might prove useful in predicting relapse risk in clinical settings and might have implications for possible interventions for relapse prevention.

Background and objectives Repeated exposure to a conditioned stimulus can lead to a reduction of conditioned fear responses towards this stimulus (i.e., extinction). However, this reduction is often fragile and sensitive to contextual changes. In the current study, we investigated whether extinction of fear responses established through verbal threat instructions is also sensitive to contextual changes. We additionally examined whether verbal instructions can strengthen the effects of a context change. Methods Fifty-two participants were informed that one colored rectangle would be predictive of an electrocutaneous stimulus, while another colored rectangle was instructed to be safe. Half of these participants were additionally informed that this contingency would only hold when the background of the computer screen had a particular color but not when it had another color. After these instructions, the participants went through an unannounced extinction phase that was followed by a context switch. Results Results indicate that extinguished verbally conditioned fear responses can return after a context switch, although only as indexed by self-reported expectancy ratings. This effect was stronger when participants were told that CS–US contingency would depend on the background color, in which case a return of fear was also observed on physiological measures of fear. Limitations Extinction was not very pronounced in this study, possibly limiting the extent to which return of fear could be observed on physiological measures. Conclusions Contextual cues can impact the return of fear established via verbal instructions. Verbal instructions can further strengthen the contextual control of fear.

Prior research showed that mere instructions about the contingency between a conditioned stimulus (CS) and an unconditioned stimulus (US) can generate fear reactions to the CS. Little is known, however, about the extent to which actual CS-US contingency experience adds anything beyond the effect of contingency instructions. Our results extend previous studies on this topic in that it included fear potentiated startle as an additional dependent variable and examined return of fear (ROF) following reinstatement. We observed that CS-US pairings can enhance fear reactions beyond the effect of contingency instructions. Moreover, for all measures of fear, instructions elicited immediate fear reactions that could not be completely overridden by subsequent situational safety information. Finally, ROF following reinstatement for instructed CS+s was unaffected by actual experience. In summary, our results demonstrate the power of contingency instructions and reveal the additional impact of actual experience of CS-US pairings.

Within relational frame theory, a distinction has been made between three types of rule-governed behavior known as pliance, tracking, and augmenting. This review examined whether there is support for the concepts of pliance, tracking, and augmenting in the experimental analysis of behavior; whether these concepts refer to distinct functional classes of behavior; and how these concepts have been operationalized in experimental (behavioral-analytic) research. Given that the concepts of pliance, tracking, and augmenting were first defined by Zettle and Hayes, we confined our review to studies published in or after 1982. Our results indicate that (a) experimental research investigating pliance, tracking, and/or augmenting is extremely limited; (b) it is difficult to determine the extent to which the concepts of pliance, tracking, and augmenting allow for relatively precise experimental analyses of distinct functional classes of behavior; and (c) pliance and tracking have been operationalized by using a limited set of procedures.

Evolutionary fear-relevant stimuli such as snakes or spiders are thought to be prepared to elicit fear reactions. This implies that the acquisition of conditioned fear responses is facilitated when these stimuli serve as conditioned stimuli (CSs). Moreover, extinction of conditioned fear responses is delayed when CSs are prepared stimuli. The research presented in this article addresses the question whether such selective learning effects can be obtained even when participants do not experience pairings of CSs and US but receive only instructions about those pairings. Two experiments were conducted in which participants were verbally informed about the relationship between fear-relevant and fear-irrelevant CSs and the presence of an electrical stimulus (US). However, CSs were never actually paired with the US. US expectancy ratings and skin conductance responses were recorded during multiple CS only trials. In the first experiment, we observed acquisition, extinction and reinstatement of fear on the basis of instructions, but these effects were not modulated by the fear-relevance of the CSs. In the second experiment, we manipulated whether participants actually experienced the CS–US contingencies or were merely instructed. We obtained facilitated acquisition for the merely instructed fear-relevant CS+. We discuss these results in relation to the evolutionary fear learning model of Ohman and Mineka (2001) and the expectancy bias model of Davey (1992).

In the context of fear conditioning, different psychophysiological measures have been related to different learning processes. Specifically, skin conductance responses (SCRs) have been related to cognitive expectancy learning, while fear potentiated startle (FPS) has been proposed to reflect affective learning that operates according to simple associative learning principles. On the basis of this two level account of fear conditioning we predicted that FPS should be less affected by verbal instructions and more affected by direct experience than SCRs. We tested this hypothesis by informing participants that contingencies would be reversed after a differential conditioning phase. Our results indicate that contingency reversal instructions led to an immediate and complete reversal of FPS regardless of the previous conditioning history. This change was accompanied by similar changes on US expectancy ratings and SCRs. These results conform with an expectancy model of fear conditioning but argue against a two level account of fear conditioning.