Gaëtan Mertens

Fear expression and return of fear following threat instruction with or without direct contingency experience

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.

Potentiation of the startle reflex is in line with contingency reversal instructions rather than the conditioning history

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.

A Systematic Review of Pliance, Tracking, and Augmenting:

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.

State anxiety modulates the return of fear

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.

The mere exposure instruction effect : mere exposure instructions influence liking

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.

Instructed fear stimuli bias visual attention

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 impact of a context switch and context instructions on the return of verbally conditioned fear

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.

The contextual malleability of approach-avoidance training effects : approaching or avoiding fear conditioned stimuli modulates effects of approach-avoidance training

ABSTRACT Previous research showed that the repeated approaching of one stimulus and avoiding of another stimulus typically leads to more positive evaluations of the former stimuli. In the current study, we examined whether approach and avoidance training (AAT) effects on evaluations of neutral stimuli can be modulated by introducing a regularity between the approach-avoidance actions and a positive or negative (feared) stimulus. In an AAT task, participants repeatedly approached one neutral non-word and avoided another neutral non-word. Half of the participants also approached a negative fear-conditioned stimulus (CS+) and avoided a conditioned safe stimulus (CS−). The other half of the participants avoided the CS+ and approached the CS−. Whereas participants in the avoid CS+ condition exhibited a typical AAT effect, participants in the approach CS+ condition exhibited a reversed AAT effect (i.e. they evaluated the approached neutral non-word as more negative than the avoided non-word). These findings provide evidence for the malleability of the AAT effect when strongly valenced stimuli are approached or avoided. We discuss the practical and theoretical implications of our findings.

A review on the effects of verbal instructions in human fear conditioning: Empirical findings, theoretical considerations, and future directions

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.

Can threat information bias fear learning? Some tentative results and methodological considerations

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.