Biomedical subjects

Bernet M Elzinga

Publications and source records attributed to Bernet M Elzinga.

13 recordsLinked to original sources

PubMed2006

Neural correlates of enhanced working-memory performance in dissociative disorder: a functional MRI study.

BACKGROUND: Memory functioning has been highlighted as a central issue in pathological dissociation. In non-pathological dissociation, evidence for enhanced working memory has been found, together with greater task-load related activity. So far, no imaging studies have investigated working memory in dissociative patients. METHOD: To assess working memory in dissociative patients functional magnetic resonance imaging was used during performance of a parametric, verbal working-memory task in patients with a dissociative disorder (n=16) and healthy controls (n=16). RESULTS: Imaging data showed that both groups activated brain regions typically involved in working memory, i.e. anterior, dorsolateral and ventrolateral prefrontal cortex (PFC), and parietal cortex. Dissociative patients showed more activation in these areas, particularly in the left anterior PFC, dorsolateral PFC and parietal cortex. In line with these findings, patients made fewer errors with increasing task load compared to controls, despite the fact that they felt more anxious and less concentrated during task performance. CONCLUSIONS: These results extend findings in non-pathological high dissociative individuals, suggesting that trait dissociation is associated with enhanced working-memory capacities. This may distinguish dissociative patients from patients with post-traumatic stress disorder, who are generally characterized by impaired working memory.

Adult↗

PubMed2006

Dissociation: cognitive capacity or dysfunction?

Dissociative experiences are mostly studied as a risk factor for dissociative pathology. Nonpathological dissociation is quite common in the general population, however, and may reflect a constitutionally determined cognitive style rather than a pathological trait acquired through the experience of adverse life events. In a theoretical model, we propose that nonpathological dissociation is characterized by high levels of elaboration learning and reconstructive retrieval, for which enhanced levels of attentional and working memory abilities are a prerequisite. These characteristics, in general, seem to be representative for a higher ability to (re-)construct conscious experiences. We review some of our behavioral as well as neural (i.e., fMRI, ERPs) studies, suggesting that high dissociative individuals are characterized by heightened levels of attention, working memory and episodic memory. In nonpathological conditions a person may benefit from these dissociative abilities, although after adverse (e.g., traumatic) events the disposition may develop into dissociative pathology.

Attention↗

PubMed2005

Stress-induced cortisol elevations are associated with impaired delayed, but not immediate recall.

Glucocorticoids are known to modulate memory functions, with elevated cortisol levels being associated with impaired declarative memory. This specific effect has been shown in several studies using pharmacological doses of cortisol. The present study was designed to assess the effects of stress-induced cortisol elevations on (1) the type of memory processing (encoding, consolidation and retrieval), and (2) on the emotional valence of the material under study. Sixteen healthy females were presented neutral and emotional material (words and paragraphs) before and after a stress challenge. Declarative memory was tested immediately after presentation and 24 h later (delayed recall). Delayed, but not immediate recall of the information presented after the stress challenge was significantly reduced compared with delayed recall of information presented before the stress challenge. In line with this, strong negative correlations were found for delayed recall of words and spatial memory presented after the challenge with post-stress cortisol levels, whereas no significant correlations were found between cortisol levels and delayed recall at day 1. These results suggest that stress-induced cortisol specifically affects long-term consolidation of declarative memories. These findings may have implications for understanding the effects of traumatic stress on memory functioning in patients with stress-related psychiatric disorders.

Adolescent↗

PubMed2005

The effects of stress-induced cortisol responses on approach-avoidance behavior.

High glucocorticoid stress-responses are associated with prolonged freezing reactions and decreased active approach and avoidance behavior in animals. The present study was designed to investigate the effects of cortisol responses and trait avoidance on approach-avoidance behavior in humans. Twenty individuals were administered a computerized approach-avoidance (AA)-task before and after stress-induction (Trier Social Stress Test). The AA-task involved a reaction time (RT) task, in which participants made affect congruent and affect incongruent arm movements towards positive and threatening social stimuli. Affect congruent responses involved arm extension (avoidance) in response to angry faces and arm flexion (approach) in response to happy faces. Reversed responses were made in affect incongruent instruction conditions. As expected, participants with high cortisol responses showed significantly decreased RT congruency-effects in a context of social stress. Low trait avoidance was also associated with diminished congruency-effects during stress. However, the latter effect disappeared after controlling for the effects of cortisol. In sum, in agreement with animal research, these data suggest that high cortisol responses are associated with a decrease in active approach-avoidance behavior during stress. These findings may have important implications for the study of freezing and avoidance reactions in patients with anxiety disorders, such as social phobia and post-traumatic stress disorder.

Adult↗

PubMed2005

Cortisol-induced impairments of working memory require acute sympathetic activation.

The present study assessed whether the effects of cortisol on working memory depend on the level of adrenergic activity (as measured by sympathetic activation) during memory performance. After exposure to a psychosocial stress task, participants were divided into cortisol responders and nonresponders. Cortisol responders showed working memory impairments during the psychosocial stress phase, when cortisol and adrenergic activity were enhanced, whereas nonresponders did not. During recovery, however, when cortisol levels were elevated but adrenergic activity was normalized, working memory of responders did not differ from that of nonresponders. Among several stress measures, cortisol was the only significant predictor for working memory performance during stress. These findings suggest that adrenergic activation is essential for the impairing effects of stress-induced cortisol on working memory.

Adolescent↗

PubMed2004

Psychophysiological reactivity to traumatic and abandonment scripts in borderline personality and posttraumatic stress disorders: a preliminary report.

Borderline personality disorder (BPD) is a highly prevalent and disabling condition linked to early stressors including traumatic abuse and abandonment. While much work has addressed traumatic events in childhood, little is known about the biological sequelae of BPD including how this disorder may be differentiated from other stress-related disorders such as posttraumatic stress disorder (PTSD). The purpose of this study was to investigate psychophysiological effects of different types of stressful reminders in BPD and in PTSD. Psychophysiological measures including heart rate, skin conductance responses, systolic and diastolic blood pressure in response to standardized neutral scripts, and personalized scripts of traumatic and abandonment situations were compared among subjects with BPD, PTSD and controls, all with a reported history of sexual and/or physical abuse before age 18. Significant script by diagnosis interactions were found for skin conductance and systolic blood pressure. No significant effects were found for diastolic blood pressure or heart rate. In the PTSD group the greatest systolic blood pressure responses were to traumatic scripts, whereas patients with BPD showed a tendency towards greater skin conductance responses to abandonment scripts. Our findings reveal only partially different psychophysiological responses to traumatic and abandonment scripts in PTSD and BPD. A divergence in pathophysiology in these two disorders is suggested that may be linked to childhood trauma. However, this interpretation must be tested in a larger population.

Adult↗

PubMed2004

A positron emission tomography study of memories of childhood abuse in borderline personality disorder.

BACKGROUND: Borderline personality disorder (BPD) is a common psychiatric disorder, which is linked to early stressors in many cases; however, the impact of traumatic events in the etiology of BPD is still unclear. This pilot study was conducted to measure the neural correlates of recall of traumatic memories in women with and without BPD. METHODS: Twenty women with a history of childhood physical or sexual abuse underwent measurement of brain blood flow with positron emission tomography imaging while they listened to scripts describing neutral and personal traumatic abuse events. Brain blood flow during exposure to trauma and neutral scripts was compared between women with and without BPD. RESULTS: Memories of trauma were associated with increases in blood flow in right dorsolateral prefrontal cortex (Brodmann's area [BA] 44 and 45) and with decreased blood flow in left dorsolateral prefrontal cortex (BA 44 and 45) in women without BPD. There was also increased blood flow in right anterior cingulate (BA 24) and left orbitofrontal cortex (BA 11) in women without BPD. Women with BPD failed to activate anterior cingulate gyrus and orbitofrontal cortex. Also, no blood flow changes were seen in dorsolateral prefrontal gyrus in women with BPD. CONCLUSIONS: Dysfunction of dorsolateral and medial prefrontal cortex, including anterior cingulate, seems to be correlated with the recall of traumatic memories in women with BPD. These brain areas might mediate trauma-related symptoms, such as dissociation or affective instability, in patients with BPD.

Adult↗

PubMed2004

Dissociative style and individual differences in verbal working memory span.

Dissociative style is mostly studied as a risk factor for dissociative pathology, but it may also reflect a fundamental characteristic of healthy information processing. Due to the close link between attention and working memory and the previous finding of enhanced attentional abilities with a high dissociative style, a positive relationship was also expected between dissociative style and verbal working memory span. In a sample of 119 psychology students, it was found that the verbal span of the high-dissociative group was about half a word larger than of the medium and low-dissociative groups. It is suggested that dissociative style may be one of only very few individual differences that is directly relevant to consciousness research.

Adolescent↗

PubMed2003

Neural correlates of memories of abandonment in women with and without borderline personality disorder.

BACKGROUND: Borderline personality disorder (BPD) is a common psychiatric disorder that is often linked to early stressors. One particularly salient feature of the disorder is fear of abandonment. This pilot study was conducted to measure neural correlates of memories of abandonment in women with and without BPD. METHODS: Twenty women with a history of childhood sexual abuse underwent measurement of brain blood flow with positron emission tomography imaging while they listened to scripts describing neutral and personal abandonment events. Brain blood flow during exposure to abandonment and neutral scripts was compared among women with and without BPD. RESULTS: Memories of abandonment were associated with greater increases in blood flow in bilateral dorsolateral prefrontal cortex (middle frontal gyrus, Brodmann's areas 9 and 10) as well as right cuneus (area 19) in women with BPD than in women without BPD. Abandonment memories were associated with greater decreases in right anterior cingulate (areas 24 and 32) in women with BPD than in women without BPD. CONCLUSIONS: These findings implicate dysfunction of dorsolateral and medial prefrontal cortex including anterior cingulate, left temporal cortex, and visual association cortex in memories of abandonment in women with BPD. These brain areas may mediate symptoms of BPD.

Adult↗

PubMed2003

Higher cortisol levels following exposure to traumatic reminders in abuse-related PTSD.

Animal studies have found that prior stressful events can result in increased reactivity in the HPA-axis. However, baseline function of the HPA-axis has typically been normal or decreased in post-traumatic stress disorder (PTSD). The first purpose of this study was to assess cortisol responsivity to traumatic reminders in women with PTSD related to childhood abuse. The second aim was to assess the relationship between stress-induced cortisol levels and neutral and emotional memory. Salivary cortisol levels were measured before, during and after exposure to personalized trauma scripts in abused women with (N=12) and without current PTSD (N=12). Memory for neutral and emotional material was assessed immediately after trauma scripts exposure and 3 days later. PTSD patients had 122% higher cortisol levels during script exposure, 69% higher cortisol levels during recovery, and 60% higher levels in the period leading up to the script exposure compared to controls. PTSD symptoms were highly predictive of cortisol levels during trauma script exposure (r=0.70), but not during periods of rest. Both in PTSD patients and controls, memory consolidation after the trauma scripts was impaired relative to baseline (P<0.001), with no differences between the two groups on memory performance. There was no association between memory performance and cortisol levels. These results are consistent with higher cortisol levels following exposure to traumatic stressors in PTSD.

Adult↗

PubMed2003

Magnetic resonance imaging of hippocampal and amygdala volume in women with childhood abuse and borderline personality disorder.

Borderline personality disorder (BPD) is a common disorder associated with emotional dysregulation and other symptoms that have been hypothesized to be related to dysfunction of limbic brain areas including hippocampus and amygdala. The purpose of this study was to measure hippocampal and amygdala volumes in BPD. Hippocampal and amygdala volumes were measured with magnetic resonance imaging (MRI) in 10 patients with BPD and 23 control subjects. Patients with BPD had a 21.9% smaller mean amygdala volume and a 13.1% smaller hippocampal volume, compared to controls. These findings are consistent with the hypothesis that alterations in the hippocampus and amygdala are associated with BPD.

Adult↗

PubMed2003

Directed forgetting between, but not within, dissociative personality states.

To investigate amnesia between identities in dissociative identity disorder (DID), the authors assessed explicit and implicit memory performance on a directed-forgetting task in 12 DID patients who switched from one state to an "amnesic" state between presentation and memory testing. DID patients were instructed either to remember or to forget neutral and emotional words. Besides an overall decrease in explicit memory, patients demonstrated selective forgetting of to-be-forgotten, but not of to-be-remembered words in the amnesic state. Patients did not exhibit any directed forgetting within the same state. Implicit memory was fully preserved across states. Independent of state, patients recalled more emotional than neutral information. These results may extend the conceptualization of memory processes in DID, suggesting an important role for retrieval inhibition.

Adult↗

PubMedDate not supplied

The relationship between dissociative proneness and alexithymia.

BACKGROUND: Dissociative reactions and alexithymia are two strategies that have been put forward as coping mechanisms to alleviate painful emotions. It is the clinical impression that dissociation is related to certain alexithymia features. In line with the coping hypothesis, it was predicted that the relationship between dissociative tendencies and alexithymia would be partly mediated by current levels of stress and/or by past traumatic experiences. Furthermore, dissociation may also be related to enhanced fantasizing, although alexithymia has traditionally been associated with an incapacity to fantasize. METHODS: Data were obtained from 833 nonclinical participants on dissociative tendencies, alexithymia, childhood abuse, current stress and socially desirable behavior. Correlation analyses followed by multiple regression were performed. RESULTS: Dissociative tendencies appeared to be especially related to one alexithymic feature: a difficulty in identifying feelings. This relationship was partially mediated by levels of current stress. A history of trauma did not predict dissociation measures. Furthermore, highly dissociative participants were more fantasy prone than low-dissociative participants. CONCLUSIONS: The results of this study support the idea that in a nonclinical group dissociation may provide a way to cope with current stressful events, and that this is associated with a difficulty in identifying feelings. It is argued that two types of dissociation may exist, one trait-like type of dissociation that is associated with fantasy proneness and other related factors, and a trauma-related type of dissociation that is more apparent within the clinical range.

Adaptation, Psychological↗