Maarten J V Peters

Publications of Maarten J V Peters

• Survival processing in times of stress.

  Authors: Tom Smeets, Henry Otgaar, Linsey Raymaekers, Maarten J V Peters, Harald Merckelbach

  Psychonomic bulletin & review. 02/2012; 19(1):113-8.

  Recent studies have found that processing information according to an evolutionary relevant (i.e., survival) scenario improves its subsequent memorability, potentially as a result of fitnessRecent studies have found that processing information according to an evolutionary relevant (i.e., survival) scenario improves its subsequent memorability, potentially as a result of fitness advantages gained in the ancestral past. So far, research has not revealed much about any proximate mechanisms that might underlie this so-called survival processing advantage in memory. Intriguingly, research has shown that the memorability of stressful situations is enhanced via the release of stress hormones acting on brain regions involved in memory. Since survival situations habitually involve some degree of stress, in the present study, we investigated whether stress serves as a proximate mechanism to promote survival processing. Participants rated words for their relevance to either a survival or a neutral (moving) scenario after they had been exposed to a psychosocial stressor or a no-stress control condition. Surprise retention tests immediately following the rating task revealed that survival processing and acute stress independently boosted memory performance. These results therefore suggest that stress does not serve as a proximate mechanism of the survival processing advantage in memory.

• Veridical and false memory for scenic material in posttraumatic stress disorder.

  Authors: Marit Hauschildt, Maarten J V Peters, Lena Jelinek, Steffen Moritz

  Consciousness and cognition. 12/2011; 21(1):80-9.

  The question whether memory aberrations in posttraumatic stress disorder (PTSD) also manifest as an increased production of false memories is important for both theoretical and practical reasons, butThe question whether memory aberrations in posttraumatic stress disorder (PTSD) also manifest as an increased production of false memories is important for both theoretical and practical reasons, but is yet unsolved. Therefore, for the present study we investigated veridical and false recognition in PTSD with a new scenic variant of the Deese-Roediger-McDermott (DRM) paradigm, which was administered to traumatized individuals with PTSD (n=32), traumatized individuals without PTSD (n=30), and non-traumatized controls (n=30). The PTSD group neither produced higher rates of false memories nor expressed more confidence in errors, but did show inferior memory sensitivity. Whereas depressive symptoms did not correlate with veridical nor false recognition, state dissociation was positively associated with false memories.

• Cognitive underperformance and symptom over-reporting in a mixed psychiatric sample.

  Authors: Brechje Dandachi-FitzGerald, Rudolf W H M Ponds, Maarten J V Peters, Harald Merckelbach

  The Clinical neuropsychologist. 07/2011; 25(5):812-28.

  The current study examined the prevalence of cognitive underperformance and symptom over-reporting in a mixed sample of psychiatric patients (N = 183). We employed the Amsterdam Short-Term MemoryThe current study examined the prevalence of cognitive underperformance and symptom over-reporting in a mixed sample of psychiatric patients (N = 183). We employed the Amsterdam Short-Term Memory Test (ASTM) to measure cognitive underperformance and the Structured Inventory of Malingered Symptomatology (SIMS) to measure the tendency to over-report symptoms. We also administered neuropsychological tests (e.g., Concept Shifting Task; Rey's Verbal Learning Test) and the Symptom Checklist-90 (SCL-90) to the patients. A total of 34% of them failed the ASTM, the SIMS or both tests. ASTM and SIMS scores were significantly, albeit modestly, correlated with each other (r = -.22). As to the links between underperformance, over-reporting, neuropsychological tasks, and the SCL-90, the association between over-reporting on the SIMS and SCL-90 scores was the most robust one. The subsample that only failed on the ASTM performed significantly worse on a compound index of memory performance. Our findings indicate that underperformance and over-reporting are loosely coupled dimensions and that particularly over-reporting is intimately linked to heightened SCL-90 scores.

• Detecting coached feigning using the Test of Memory Malingering (TOMM) and the Structured Inventory of Malingered Symptomatology (SIMS).

  Authors: Marko Jelicic, Erik Ceunen, Maarten J V Peters, Harald Merckelbach

  Journal of clinical psychology. 04/2011; 67(9):850-5.

  Undergraduate students were administered the Test of Memory Malingering (TOMM) and the Structured Inventory of the Malingered Symptomatology (SIMS) and asked to respond honestly, or instructed toUndergraduate students were administered the Test of Memory Malingering (TOMM) and the Structured Inventory of the Malingered Symptomatology (SIMS) and asked to respond honestly, or instructed to feign cognitive dysfunction due to head injury. Before both instruments were administered, symptom-coached feigners were provided with some information about brain injury, while feigners who received a mix of symptom-coaching and test-coaching were given the same information plus advice on how to defeat symptom validity tests. Results show that, although the accuracy of both instruments appears to be somewhat reduced by a mix of symptom coaching and test coaching, the TOMM and SIMS are relatively resistant to different kinds of coaching.

• Underestimation of prior remembering and susceptibility to false memories: two sides of the same coin?

  Authors: Linsey Raymaekers, Maarten J V Peters, Tom Smeets, Latifa Abidi, Harald Merckelbach

  Consciousness and cognition. 01/2011; 20(4):1144-53.

  In two studies, we explored whether susceptibility to false memories and the underestimation of prior memories (i.e., forgot-it-all-along effect) tap overlapping memory phenomena. Study 1In two studies, we explored whether susceptibility to false memories and the underestimation of prior memories (i.e., forgot-it-all-along effect) tap overlapping memory phenomena. Study 1 investigated this issue by administering the Deese/Roediger-McDermott task (DRM) and the forgot-it-all-along (FIA) task to an undergraduate sample (N=110). It was furthermore explored how performances on these tasks correlate with clinically relevant traits such as fantasy proneness, dissociative experiences, and cognitive efficiency. Results show that FIA and DRM performances are relatively independent from each other, suggesting that these measures empirically apparently refer to separate dimensions. However, they do not seem to define different profiles in terms of dissociation, fantasy proneness, and cognitive efficiency. Study 2 replicated the finding of relative independence between false memory propensity (as measured with the DRM task) and the underestimation of prior memories (as measured with an autobiographical memory dating task) in people with a history of childhood sexual abuse (N=35).

• Metacognitive beliefs in obsessive-compulsive patients: a comparison with healthy and schizophrenia participants.

  Authors: Steffen Moritz, Maarten J V Peters, Frank Larøi, Tania M Lincoln

  Cognitive neuropsychiatry. 05/2010; 15(6):531-48.

  Distorted metacognitive beliefs are increasingly considered in theoretical models of obsessive-compulsive disorder (OCD). However, so far no consensus has emerged regarding the specific metacognitiveDistorted metacognitive beliefs are increasingly considered in theoretical models of obsessive-compulsive disorder (OCD). However, so far no consensus has emerged regarding the specific metacognitive profile of OCD. Participants with OCD (n=55), schizophrenia (n=39), and nonclinical controls (n=49) were assessed with the Metacognitions Questionnaire (MCQ-30). Except for positive beliefs about worry, both patient samples exceeded nonclinical controls on all MCQ subscales. The MCQ "need to control thoughts" and "negative beliefs about uncontrollability and danger" subscales showed strong correlations with obsessions, and scores in the former scale were elevated in hallucinators. In contrast to several prior studies, "cognitive confidence" was related neither to core OCD nor to schizophrenia symptomatology. Notwithstanding large pathogenetic differences between OCD and schizophrenia, findings suggest that obsessions and hallucinations may share a common metacognitive pathway. Need to control thoughts and dysfunctional beliefs about the malleability of worries may represent critical prerequisites for the two phenomena to emerge.

• Autobiographical memory specificity among people with recovered memories of childhood sexual abuse.

  Authors: Linsey Raymaekers, Tom Smeets, Maarten J V Peters, Harald Merckelbach

  Journal of behavior therapy and experimental psychiatry. 03/2010; 41(4):338-44.

  Individuals who report to have recovered memories of childhood sexual abuse (CSA) almost by definition believe that these memories were previously inaccessible for them. We examined whether poorIndividuals who report to have recovered memories of childhood sexual abuse (CSA) almost by definition believe that these memories were previously inaccessible for them. We examined whether poor autobiographical memory specificity for all kinds of events (i.e., events not necessarily related to CSA) may underlie such impressions of amnesia. Thus, we examined whether people who report recovered memories of CSA (n=44) would exhibit more difficulty retrieving specific autobiographical memories compared to people who never forgot their abuse experiences (continuous memory group; n=42) and people without a history of abuse (controls; n=26). The standard Autobiographical Memory Test (AMT) was administered to these 3 groups along with measures of depression and posttraumatic stress disorder symptomatology. Controls were significantly better at retrieving specific autobiographical memories relative to individuals with continuous and recovered CSA memories, who did not differ from each other. Thus, reduced autobiographical memory specificity was not particularly pronounced in people with recovered memories of CSA. Poor autobiographical memory specificity is unlikely to explain the impression of amnesia reported by this group.

• The corrective effects of warning on false memories in the DRM paradigm are limited to full attention conditions.

  Authors: Maarten J V Peters, Marko Jelicic, Benny Gorski, Kevin Sijstermans, Timo Giesbrecht, Harald Merckelbach

  Acta psychologica. 11/2008; 129(2):308-14.

  Effects of attention control and forewarning on the activation and monitoring of experimentally induced false memories in the Deese/Roediger-McDermott paradigm were investigated in a young adultEffects of attention control and forewarning on the activation and monitoring of experimentally induced false memories in the Deese/Roediger-McDermott paradigm were investigated in a young adult sample (N=77). We found that reducing the degree of attention during encoding led to a decrease in veridical recall and an increase in non-presented critical lure intrusions. This effect could not be counteracted by a forewarning instruction. However, these findings did not emerge in a (retrieval supportive) recognition task. It seems that divided attention increases false recall when attention control and forewarning have to compete for limited cognitive resources in a generative free recall as opposed to a retrieval supportive recognition task. Forewarning instructions do not always protect young adults against experimentally induced false memories.

• Confusing action and imagination: action source monitoring in individuals with schizotypal traits.

  Authors: Maarten J V Peters, Tom Smeets, Timo Giesbrecht, Marko Jelicic, Harald Merckelbach

  The Journal of nervous and mental disease. 10/2007; 195(9):752-7.

  To explore whether schizotypal traits may undermine source monitoring for actions, 67 undergraduate participants (21 men) completed the Schizotypal Personality Scale and were then given aTo explore whether schizotypal traits may undermine source monitoring for actions, 67 undergraduate participants (21 men) completed the Schizotypal Personality Scale and were then given a source-monitoring task in which some specific acts had to be performed, whereas others only had to be imagined. Next, participants had to complete an old-new recognition task and ascribe the source, i.e., whether they had performed or only imagined the items (i.e., source monitoring). Participants also completed a working memory capacity task (i.e., Operation Span task). We found that the higher the Schizotypal Personality Scale scores, the poorer recognition and source attribution scores. Relative to participants with low levels of schizotypal traits (i.e., controls), those with higher levels of schizotypal traits more often falsely claimed to have performed actions when in fact they had only imagined them. Although participants high and low in schizotypical traits did not differ in their working memory capacity, poor working memory capacity was related to source misattribution (i.e., increase false alarms). The present findings indicate that schizotypal traits undermine source monitoring for action in a healthy population.

• Did I say that word or did you? Executive dysfunctions in schizophrenic patients affect memory efficiency, but not source attributions.

  Authors: Maarten J V Peters, Maaike J Cima, Tom Smeets, Marije de Vos, Marko Jelicic, Harald Merckelbach

  Cognitive neuropsychiatry. 10/2007; 12(5):391-411.

  INTRODUCTION: Schizophrenic patients have difficulties in recognising previously presented verbal information and identifying its sources. The antecedents of these recognition and sourceINTRODUCTION: Schizophrenic patients have difficulties in recognising previously presented verbal information and identifying its sources. The antecedents of these recognition and source misattributions are, however, largely unknown. The current study examined to what extent schizophrenic patients' lack of memory efficiency, their memory errors, and their source misattributions are related to neurocognitive deficits (i.e., executive dysfunctions). METHODS: 23 schizophrenic patients and 20 healthy controls were administered an adapted version of the Deese/Roediger-McDermott (DRM) task from which parameters of memory efficiency, memory errors, source misattributions, and two-high threshold measures were derived. Furthermore, two neurocognitive tasks tapping executive functions were administered: the Wisconsin Card Sorting Test (WCST) and the Behavioural Assessment of the Dysexecutive Syndrome (BADS). Using multiple linear regression analyses, we examined whether these neurocognitive measures predicted various memory parameters. RESULTS: Patients with schizophrenia showed poorer memory efficiency and were more prone to make internal-external source misattributions with high confidence. However, they did not more often falsely recognise critical lure words than controls. Executive dysfunctions predicted memory efficiency, but not source misattribution performance. CONCLUSION: Our findings provide further evidence that schizophrenic patients' memory impairments are intimately related to fundamental neurocognitive deficits.

• The false fame illusion in people with memories about a previous life.

  Authors: Maarten J V Peters, Robert Horselenberg, Marko Jelicic, Harald Merckelbach

  Consciousness and cognition. 04/2007; 16(1):162-9.

  The present study examined whether individuals with full-blown memories of highly implausible events are prone to commit source monitoring errors. Participants reporting previous-life memories andThe present study examined whether individuals with full-blown memories of highly implausible events are prone to commit source monitoring errors. Participants reporting previous-life memories and those without such memories completed a false fame task. This task provides an index of source monitoring errors (i.e., misclassifying familiar non-famous names as famous names). Participants with previous-life memories had a greater tendency to judge the names of previously presented non-famous people as famous than control participants. The two groups did not differ in terms of correct recognition of new non-famous names and famous names. Although dissociation, cognitive failures, sleep-related experiences, depressive symptoms, and signs of psychological distress were all significantly higher in participants with previous-life memories than in controls, these variables did not predict the false fame illusion.

• Mild executive dysfunctions in undergraduates are related to recollecting words never presented.

  Authors: Maarten J V Peters, Marko Jelicic, Nicole Haas, Harald Merckelbach

  The International journal of neuroscience. 10/2006; 116(9):1065-77.

  The aim of this study was to explore whether individual differences in executive function in undergraduate students (n = 72) contribute to false recall and recognition as obtained with theThe aim of this study was to explore whether individual differences in executive function in undergraduate students (n = 72) contribute to false recall and recognition as obtained with the Deese/Roediger-McDermott (DRM) paradigm. Participants were subjected to the DRM paradigm and also were given a test designed to assess executive function--the Random Number Generation task (RNG). A relationship was found between heightened seriation on the RNG (indicating a deficiency in the ability to inhibit cognitive schemes) and false recognition of non-presented, critical lure words in the DRM paradigm. This suggests that individual differences in executive function do occur in a healthy population and that the reconstructive activity inherent in memory depends in part on executive functioning.

• Underestimation of prior remembering and susceptibility to false memories: Two sides of the same coin?

  Authors: Linsey Raymaekers, Maarten J.V. Peters, Tom Smeets, Latifa Abidi, Harald Merckelbach

  Consciousness and Cognition.

  In two studies, we explored whether susceptibility to false memories and the underestimation of prior memories (i.e., forgot-it-all-along effect) tap overlapping memory phenomena. Study 1In two studies, we explored whether susceptibility to false memories and the underestimation of prior memories (i.e., forgot-it-all-along effect) tap overlapping memory phenomena. Study 1 investigated this issue by administering the Deese/Roediger–McDermott task (DRM) and the forgot-it-all-along (FIA) task to an undergraduate sample (N = 110). It was furthermore explored how performances on these tasks correlate with clinically relevant traits such as fantasy proneness, dissociative experiences, and cognitive efficiency. Results show that FIA and DRM performances are relatively independent from each other, suggesting that these measures empirically apparently refer to separate dimensions. However, they do not seem to define different profiles in terms of dissociation, fantasy proneness, and cognitive efficiency. Study 2 replicated the finding of relative independence between false memory propensity (as measured with the DRM task) and the underestimation of prior memories (as measured with an autobiographical memory dating task) in people with a history of childhood sexual abuse (N = 35).

• The false fame illusion in people with memories about a previous life

  Authors: Maarten J.V. Peters, Robert Horselenberg, Marko Jelicic, Harald Merckelbach

  Consciousness and Cognition.

  The present study examined whether individuals with full-blown memories of highly implausible events are prone to commit source monitoring errors. Participants reporting previous-life memories andThe present study examined whether individuals with full-blown memories of highly implausible events are prone to commit source monitoring errors. Participants reporting previous-life memories and those without such memories completed a false fame task. This task provides an index of source monitoring errors (i.e., misclassifying familiar non-famous names as famous names). Participants with previous-life memories had a greater tendency to judge the names of previously presented non-famous people as famous than control participants. The two groups did not differ in terms of correct recognition of new non-famous names and famous names. Although dissociation, cognitive failures, sleep-related experiences, depressive symptoms, and signs of psychological distress were all significantly higher in participants with previous-life memories than in controls, these variables did not predict the false fame illusion.