Biomedical subjects

Dirk Hermans

Publications and source records attributed to Dirk Hermans.

At least 19 recordsLinked to original sources

PubMed2006

The repeated confrontation with videotapes of spiders in multiple contexts attenuates renewal of fear in spider-anxious students.

In a treatment-analogue experiment, extinction of fear of spiders was investigated in a group of spider-anxious students. Two groups were created: in the single extinction group the extinction trials consisted of repeated presentations of a videotaped spider in one specific location of a house, whereas in the multiple extinction group the trials consisted of videotapes of the same spider in three different locations of a house. Also a control group was included that was exposed to videotapes of the location but without the spider. As reflected in skin conductance responses and self-report data, fear of spiders was significantly reduced in the two extinction groups compared to the control group. Moreover, when the extinction groups were confronted with the videotape of the spider in a new location, the single extinction group did not show generalisation of extinction, whereas the multiple extinction group did. These results corroborate the existing evidence for context dependence of extinction of fear and provide new evidence that the use of multiple contexts during extinction might improve the generalisability of extinction in humans. Implications for exposure therapy are discussed.

Adolescent↗

PubMed2006

Verbal, behavioural and physiological assessment of the generalization of exposure-based fear reduction in a spider-anxious population.

Clinical fear of spiders was assessed in 39 patients before and after exposure treatment and at a 3-month follow-up. The assessment included behavioral, physiological and self-report measures. Some patients were tested in the treatment context (group Same), while others were tested in a different context (group Different). Both groups demonstrated a significant fear reduction from pre- to post-treatment in all measures, which persisted at the 3-month follow-up. Contrary to our expectations, no clear difference was observed between the groups at any moment. However, a 1-year follow-up test of the self-report measure revealed a return of fear in group Same, but not in group Different. These results show (1) that the effects of exposure treatment persisted over contexts and time in the short term, and (2) that conducting treatment and tests in different contexts enhanced efficiency of exposure treatment in the long term.

Animals↗

PubMed2006

Concurrent excitors limit the extinction of conditioned fear in humans.

In a human fear conditioning experiment, with on-line expectancy ratings and electrodermal responding as indices of fear, two neutral stimuli (pictures of geometric shapes) were first established as reliable predictors of an electric shock. In the subsequent extinction phase, the two stimuli were repeatedly presented in compound, without the shock. The final test phase consisted of individual stimulus presentations again, which resulted in a strong return of the conditioned responses. This effect was not observed in non-conditioned control stimuli. Hence, behavioral effects of extinction seem highly specific to the stimulus constellation that has gone through the extinction procedure. We argue that pharmacological, behavioral and/or cognitive manipulations that could prevent configural processing of stimulus constellations have direct clinical potential.

Conditioning, Psychological↗

PubMed2006

Extinction in human fear conditioning.

Although most extinction research is conducted in animal laboratories, the study of extinction learning in human fear conditioning has gained increasing attention over the last decade. The most important findings from human fear extinction are reviewed in this article. Specifically, we review experimental investigations of the impact of conditioned inhibitors, conditioned exciters, context renewal, and reinstatement on fear extinction in human samples. We discuss data from laboratory studies of the extinction of aversively conditioned stimuli, as well as results from experimental clinical work with fearful or anxious individuals. We present directions for future research, in particular the need for further investigation of differences between animal and human conditioning outcomes, and research examining the role of both automatic and higher-order cognitive processes in human conditioning and extinction.

Animals↗

PubMed2006

Stronger renewal in human fear conditioning when tested with an acquisition retrieval cue than with an extinction retrieval cue.

It was previously demonstrated in our laboratory that conditioned fear in humans can renew after extinction, when this procedure took place in a different context (ABA-renewal [Vansteenwegen et al. (2005). Return of fear in a human differential conditioning paradigm caused by a return to the original acquisition context. Behaviour Research and Therapy, 43(3), 323-336]). Using the same experimental design, we now tested the power of retrieval cues to interact with this contextual renewal phenomenon. Two groups went through acquisition and extinction (in a different context). They were then tested in the original acquisition context and in the presence of a retrieval cue. In the acquisition-cue group, this cue previously featured during the acquisition procedure; in the extinction-cue group, the cue previously featured during the extinction procedure. As expected, renewal of conditioned electro-dermal responding and retrospective expectancy ratings was strongest in the acquisition-cue group. Theoretical and clinical implications of this finding are discussed.

Association Learning↗

PubMed2006

Determinants and predictive validity of direct and indirect measures of recently acquired food attitudes.

The present study examined whether the affective priming paradigm in the picture-picture naming task can be used to measure recently acquired food attitudes. Food (dis)likes were induced by an evaluative learning procedure in which real food items were contingently paired with sensory liking or expected consequences information. It was found that the picture-picture naming task is capable of measuring recently induced food attitudes irrespective of whether they were based on sensory liking or expected consequences information. In addition, we observed that affective priming effects that are obtained with the naming task can be used to predict food-related choice behaviour, irrespective of whether participants are given time to elaborate on their choice or not. The latter finding, however, emerged only when food attitudes were based on sensory liking.

Adult↗

PubMed2006

Reduced autobiographical memory specificity and rumination in predicting the course of depression.

Reduced autobiographical memory (AM) specificity is a known vulnerability factor for depression. AM specificity was investigated as a predictor of depression with the Autobiographical Memory Test (J. M. G. Williams & K. Broadbent, 1986). When baseline depression scores were partialed, reduced AM specificity to negative cue words predicted higher levels of depression at 7-month follow-up. Once rumination was taken into account by means of the Rumination on Sadness Scale (M. Conway, P. A. R. Csank, S. L. Holm, & C. K. Blake, 2000), AM specificity no longer predicted depression, suggesting that the predictive value of AM specificity observed in previous studies might be--at least partly--explained as an effect of rumination. Further mediation analyses indeed revealed support for rumination as a mediator of the relation between reduced AM specificity and poor outcome of depression.

Adult↗

PubMed2006

Is overgeneral autobiographical memory an isolated memory phenomenon in major depression?

The present study explored the relation between overgeneral autobiographical memory (AM) and other aspects of memory functioning in depression. A total of 26 patients with major depressive disorder completed a set of memory tasks measuring AM specificity (AMT; Williams & Broadbent, 1986), working memory, semantic memory, verbal learning, delayed verbal recall, recognition memory, and source memory. Reduced specificity of AM was related to poor working memory (central executive functioning) and poor source memory. The former finding conforms to the idea that the voluntary retrieval of specific autobiographical memories (AMs) involves central executive processes (e.g., Conway & Pleydell-Pearce, 2000). The latter finding replicates and extends recent findings suggesting that overgeneral AM is part of a broader memory deficit in retrieving the specific details of the context in which information was acquired (Ramponi, Barnard, & Nimmo-Smith, 2004). Furthermore, in line with Ramponi et al. (2004), rumination was found to be related to both overgeneral AM and poor source memory.

Adult↗

PubMed2006

Negative bias in the perception of others' facial emotional expressions in major depression: the role of depressive rumination.

Depressed individuals display a negative bias in the perception of others' facial emotional expressions. The extent of this selective processing, moreover, has proven predictive of a poor outcome in depression. However, to date, little is known about the possible mechanisms that may account for this bias. This study examined the hypothesis that rumination--an analytical type of self-focused attention--would be associated with higher levels of perception of negative facial emotions in major depression. Twenty-six depressed patients (17 women) completed the Perception of Facial Expressions Questionnaire, the Ruminative Response Scale, and other measures assessing depression-related constructs. Consistent with prediction, rumination was positively related to a negative bias in the judgment of facial expressions, even when controlling for other depression-related variables. Although the correlational design of the present study limits the extent to which conclusions can be drawn on the directionality of the observed relationship, the present study reveals self-focused rumination as a possibly important causal mechanism in explaining depressed persons' negative bias in the perception of others' facial emotions.

Adult↗

PubMed2005

The role of extinction and reinstatement in attentional bias to threat: a conditioning approach.

We investigated the effects of extinction and reinstatement on attentional bias to fear-conditioned signals in healthy individuals using an emotional modification of a spatial cueing paradigm. Spatial cues were emotionally modulated using differential conditioning. The CS+ was sometimes followed by an aversive electrocutaneous stimulus (UCS), whereas the CS- was never followed by the UCS. During a subsequent extinction phase no UCS was presented anymore. The reinstatement phase started with one or four unpredicted UCS-only trials for half of the participants (reinstatement group). For the other half there were no additional UCS presentations (control group). We found that attention was biased to threat signals during acquisition. This biased attention largely disappeared during extinction. During the reinstatement phase attentional bias to threat signals re-emerged in the reinstatement group, but not in the control group.

Adolescent↗

PubMed2005

Return of fear in a human differential conditioning paradigm caused by a return to the original acquistion context.

In a differential human fear conditioning paradigm evidence for ABA-renewal was obtained manipulating the lighting in the experimental room. During acquisition in either a dark or illuminated room, one neutral slide was sometimes paired with a loud aversive noise whereas another slide was not. Subsequently, extinction took place in the opposite lighting context. When afterwards the participants were tested again in the original acquisition context, measurements revealed a recovery of the conditioned electrodermal response and an increase in the retrospective verbal US-expectancy ratings. No response recovery was obtained in an AAA-group that received acquisition, extinction and test trials in one and the same context. Several theoretical explanations for this type of return of fear as well as implications for clinical practice are discussed.

Conditioning, Classical↗

PubMed2005

Return of fear in a human differential conditioning paradigm caused by a stimulus change after extinction.

In a human fear conditioning experiment, 32 participants were trained in a differential conditioning procedure with geometrical shapes as CS+ and CS- (four presentations each), and an electric shock as US. Measures of conditioned responding were skin conductance response (SCR) and retrospective US-expectancy ratings. For half of the participants (Generalization Group, GG), the subsequent extinction phase consisted of four nonreinforced presentations of generalization stimuli (GS+ and GS-). Participants from the Extinction control Group received an equal amount of nonreinforced presentations of the CSs. Finally, all participants were tested with the original CSs. The results from both measures clearly show an increase in the size of the discrimination upon the stimulus change after extinction in the GG. Because this pattern is not observed in the Extinction control Group, extinction performance appears to be somehow restricted to the perceptual characteristics of the extinction stimulus. Interestingly, the size of the conditioned SCR discrimination in the GG is not influenced by the stimulus change after acquisition. This observation points to a differential impact of stimulus change after acquisition vs. extinction treatment. The findings are discussed from the theoretical perspective of renewal and the clinical perspective of Return of Fear.

Analysis of Variance↗

PubMed2005

Reinstatement of fear responses in human aversive conditioning.

The treatment of choice for a number of anxiety disorders is exposure therapy. However, successful reduction of fear through exposure is sometimes followed by a (partial) return of symptoms of fear (return of fear, ROF; Clin. Psychol. Rev. 9 (1989) 147). Several possible learning mechanisms have been suggested to explain ROF (e.g. mechanisms related to spontaneous recovery, renewal, reacquisition and reinstatement). The present study focuses on reinstatement, which refers to the observation that mere US-only presentations can 'reinstate' previously extinguished fear responses. Although animal research has repeatedly demonstrated this phenomenon, little is known about fear reinstatement in humans. The present study employed a differential aversive conditioning procedure: after acquisition and a subsequent extinction procedure, a series of four unpredicted US-only trials was scheduled in the reinstatement group. The control group did not receive additional US presentations. A significant reinstatement effect was observed for US-expectancy ratings and fear ratings in the reinstatement group, but not in the control group. No differences were observed in a reaction time measure of resource allocation to the conditioned stimuli. These findings constitute a first demonstration of reinstatement of conditioned fear responses in humans. Implications for exposure treatment and suggestions for future research are discussed.

Adult↗

PubMed2005

Reduced specificity of autobiographical memory: a mediator between rumination and ineffective social problem-solving in major depression?

BACKGROUND: Depressed individuals display a deficit in effectively solving social problem situations (e.g., []). Recent research suggests that rumination may interfere with such effective problem-solving (e.g., []). However, little is known, as yet, about the mechanisms that are underlying this relation between rumination and poor problem-solving. The present study investigated the role of reduced specificity of autobiographical memories as a mediator of this relationship. METHODS: 24 depressed patients (15 women) completed the Autobiographical Memory Test (AMT), the Means-Ends Problem-Solving Task (MEPS), the Ruminative Response Scale (RRS) and the Rumination on Sadness Scale (RSS). RESULTS: Consistent with previous studies, rumination, ineffective problem-solving and reduced memory specificity were significantly associated. Regression analyses further extended these findings by showing that reduced memory specificity mediated the association between rumination and problem-solving effectiveness. LIMITATIONS: The correlational nature of this study limits to some extent the conclusions that can be drawn on the directionality of the observed relationships. CONCLUSIONS: Results offer support for the idea that lack of autobiographical memory specificity mediates the known relationship between rumination and poor problem-solving.

Autobiographies as Topic↗

PubMed2005

Affective priming as an indirect measure of food preferences acquired through odor conditioning.

The present study aimed at investigating affective priming for originally neutral food stimuli that recently acquired their affective meaning through odor conditioning. In a first phase, pictures of different brands of yogurts (CSs) were contingently presented with a positive or negative odor (US). In a subsequent phase, the yogurt CSs were used as primes in an affective priming procedure. Rating data showed that the acquisition procedure resulted in a reliable evaluative learning effect. This could be corroborated by the results of the priming task. Participants responded faster to positive target words and made fewer errors when they were preceded by a CS that had been associated with a positive odor, as compared to a CS that was associated with a negative odor. A reversed pattern was present for negative targets. Based on these findings, it is suggested that affective priming might be used as a demand-free measure of evaluative learning.

Adult↗

PubMed2005

Unintentional processing of motivational valence.

Recent motivational affective priming studies (Moors & De Houwer, 2001; Moors, De Houwer, & Eelen, 2004) showed that primes that indicate success on a goal-inducing task facilitate positive target responses whereas primes that indicate failure on that task facilitate negative target responses. In the current studies, we examined whether these priming effects depend on consciously intentional processing of the motivational valence of the primes. In Experiment 1, the outcome of success or failure was presented not only immediately before the target (i.e., the prime) but also a second time after the target response. This should encourage participants to ignore the prime. In Experiment 2, participants were asked to respond to the targets within 600 ms after target onset. As a result, participants had little opportunity to process the motivational prime valence in a consciously intentional way. Nevertheless, strong affective priming effects were found in both studies. These results provide additional support for the claim that motivational valence can be processed without the conscious intention to do so.

Adult↗

PubMed2005

Autobiographical memory specificity and emotional abuse.

OBJECTIVE: Examined the relationship between trauma and memory specificity and the importance in this of level of support received. METHOD: Fifty-two female undergraduates completed the Autobiographical Memory Test (AMT; Williams and Broadbent, 1986), assessing memory specificity and the Traumatic Experiences Checklist (TEC; Nijenhuis, Van der Hart, and Vanderlinden, 1999), assessing qualitative aspects of trauma. RESULTS: In low-specific students, those who reported emotional abuse were less specific in their memory. The scores of students who had not received any support for the abuse showed a trend towards retrieval of less specific memories, as compared with those who had received support. CONCLUSION: Results provide evidence for an association between trauma (emotional abuse) and reduced memory specificity, and suggest that receiving support following the abuse might protect individuals from developing over-general memory.

Adolescent↗

PubMed2005

Reduced autobiographical memory specificity as an avoidant coping style.

OBJECTIVE: Previous studies suggest that reduced autobiographical memory specificity might serve as a way of regulating affect. This study examined the relationship between autobiographical memory specificity and avoidant coping. METHOD: Sixty students completed the Autobiographical Memory Test (AMT). Different types of avoidant coping were assessed using questionnaires: the Acceptance and Action Questionnaire, the Cognitive-Behavioural Avoidance Scale and the White Bear Suppression Inventory. RESULTS: For all questionnaires, a significant correlation was observed between the number of specific responses on the AMT and an avoidant coping style. More avoidance was associated with fewer specific answers. These correlations remained when corrected for number of omissions. CONCLUSION: The results provide further evidence for the affect-regulating quality of autobiographical memory specificity.

Adaptation, Psychological↗