Biomedical subjects

Merel Kindt

Publications and source records attributed to Merel Kindt.

5 recordsLinked to original sources

PubMed2003

Peritraumatic dissociation and posttraumatic stress after pregnancy loss: a prospective study.

This study examined (1). predictors for peritraumatic dissociation, (2). its relations with acute and chronic symptoms of posttraumatic stress disorder (PTSD), and (3). pathways regarding these relations in response to pregnancy loss. In early pregnancy, about 1370 women volunteers completed questionnaires for neuroticism, control over emotions, dissociative tendencies, absorption, and prior life events. Of these, 126 subsequently experienced pregnancy loss and most of them completed measures 1 month (N = 118) and 4 months (N = 104) later. At 1 month, peritraumatic dissociation, memory of pregnancy loss (degree of fragmentation, sensory impressions, and emotional intensity), thought suppression, and PTSD symptoms were assessed, and at 4 months, PTSD symptoms were re-assessed. Peritraumatic dissociation was predicted by prior low control over emotions, dissociative tendencies, and lower education. It was not predicted by neuroticism, absorption, and prior life events. Peritraumatic dissociation was related to acute PTSD symptoms and LISREL analyses indicated that self-reported memory fragmentation and thought suppression of pregnancy loss mediated this relation. It also predicted chronic PTSD symptoms, and this relation was mediated by acute PTSD symptoms.

Abortion, Spontaneous↗

PubMed2003

Dissociation and memory fragmentation: experimental effects on meta-memory but not on actual memory performance.

The relation between state dissociation and fragmentary memory was investigated by assessing both actual memory performance and meta-memory. From a sample of 330 normal subjects, two subsamples were selected on basis of trait dissociation, as measured by the Dissociative Experience Scale. Twenty subjects scoring above 30 and 20 subjects scoring below 10 were selected. Subjects watched an extremely aversive film, after which state dissociation was measured by the Peri-traumatic Dissociative Experience Scale. Four hours later memory fragmentation was assessed in two ways. Actual fragmentation was measured by a sequential memory task, and perceived fragmentation (meta-memory) was measured using a visual analogue scale. Subjects who tended to dissociate during the film judged their recollections of the film as more fragmentary. Although this finding is in line with clinical reports given by trauma victims, it was not sustained by objective evidence. That is, no effect was observed of state dissociation on the sequential memory task. The present findings suggest that the claim that dissociation induces memory fragmentation may have to be confined to meta-memory. Implications of this divergence between actual memory and meta-memory are discussed.

Adult↗

PubMed2003

Repeated checking causes memory distrust.

This paper attempts to explain why in obsessive-compulsive disorder (OCD) checkers distrust in memory persists despite extensive checking. It is argued that: (1) repeated checking increases familiarity with the issues checked; (2) increased familiarity promotes conceptual processing which inhibits perceptual processing; (3) inhibited perceptual processing makes recollections less vivid and detailed and finally; (4) reduction in vividness and detail promotes distrust in memory. An interactive computer animation was developed in which participants had to perform checking rituals on a virtual gas stove. Two separate experiments were carried out with n=39 (Experiment I) and n=40 (Experiment II) healthy participants. In both studies, the control group and the experimental group were given the same pre-test and post-test on the virtual gas stove. In between, the experimental group engaged in 'relevant checking', i.e. checking the gas stove, while the control group engaged in 'irrelevant checking', i.e. checking virtual light bulbs. In both experiments there were powerful effects of repeated 'relevant checking': while actual memory accuracy remained unaffected, the vividness and detail of the recollections were greatly reduced. Most pertinently, in both experiments relevant checking undermined confidence in memory. No such effects were observed in the control group. One might argue that the pre-test/post-test design may have made the control group anticipate a memory assessment at the post-test and that this artifact made them relatively alert producing memory confidence at post test that was artificially high. A third experiment was carried out (n=2 x 20) in which no pre-test was given while, other than that, Experiment III was identical to the first two experiments. Results confirmed earlier findings: compared to the irrelevant checking control group, recollections in the relevant checking group were non-vivid, non-detailed while confidence in memory was low. The theory and data suggest an answer to the question 'why memory distrust persists despite repetitive checking'. In people who check extensively, memory distrust may persist as a result of repetitive checking. OCD checking may be motivated by the wish to reduce uncertainty, but checking appears to be a counter-productive safety strategy. Rather than reducing doubt, checking fosters doubt and ironically increases meta-memory problems.

Adult↗

PubMed2003

Phenomenological validity of an OCD-memory model and the remember/know distinction.

In earlier experiments using interactive computer animation with healthy subjects, it was found that displaying compulsive-like repeated checking behavior affects memory. That is, checking does not alter actual memory accuracy, but it does affect 'meta-memory': as checking continues, recollections are experienced as less vivid and less detailed while confidence in memory is undermined. This procedure provides a model of OCD checking and suggests that checking is a counterproductive strategy to reduce memory distrust. The present experiment was carried out to specify the phenomenological quality of memory distrust after checking and to see if repeated checking produces a shift in the memory source that is used to decide about the outcome of checking: from 'remembering' to 'knowing' (Tulving, 1985). Using the same interactive computer-animation, the earlier findings on vividness, detail and confidence were replicated. In addition, it was found that checking made participants endorse quotations from OCD patients (Reed, 1985) expressing a specific ambivalence about memory: 'It is as though the memory is there, but is isn't definite enough', 'I remember doing it in a way, but it's all fuzzy....' And 'I can remember that I've done it. But the memory isn't clear somehow'. This finding adds to the validity of the experimental model. Furthermore, after checking subjects' beliefs about the outcome of checking became based on (general) knowing instead of (specific) remembering. It is suggested that OCD checkers feel a general and relatively strong need to be certain about the veracity of recollections and that they have high standards for memory performance. This may explain earlier findings that OCD checkers have a general tendency to distrust their episodic memory. A need for certainty and a critical attitude towards memory performance may not be problematic or abnormal. It is suggested that clinical problems arise when the patient tries to fight memory distrust by repeated checking. The latter does not reduce distrust but rather increases distrust and the patient may get trapped in a spiral of mutually reinforcing checking behavior and memory distrust.

Adult↗

PubMedDate not supplied

Instructed neutralization, spontaneous neutralization and prevented neutralization after an obsession-like thought.

Building on two earlier experiments (Behav. Res. Ther. 34 (1996) 889; 39 (2001) 1439) the present study investigated the effects of neutralizing the consequences of an obsession-like thought in healthy participants. Just like in the earlier studies, writing out and thinking over such a thought generated anxiety. After this provocation, 40 of the 120 participants were instructed to neutralize the effects of the thought for 2 min, 40 participants did not receive a particular instruction, and the remaining 40 participants were instructed to do mental arithmetic aloud so as to prevent "spontaneous" attempts at neutralizing the thought. The no instruction group reported that they neutralized (spontaneously) to the same degree as the group that was instructed to neutralize. Within 2 min, anxiety decreased to near base line levels and there were no differences between the three conditions. When the groups were asked to bring the obsession-like thought back to consciousness again, anxiety increased slightly. Yet, contrary to expectation, this increase in anxiety did not discriminate the "neutralization prevention" group from the other two groups. Limitations of the paradigm as a model for clinical obsessions are discussed.

Adult↗