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Results for “Memory Disorders”

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PubMed1988

Memory loss from a subcortical white matter infarct.

Clinical disorders of memory are believed to occur from the dysfunction of either the mesial temporal lobe, the mesial thalamus, or the basal forebrain. Fibre tract damage at the level of the fornix has only inconsistently produced amnesia. A patient is reported who suffered a cerebrovascular accident involving the posterior limb of the left internal capsule that resulted in a persistent and severe disorder of verbal memory. The inferior extent of the lesion effectively disconnected the mesial thalamus from the amygdala and the frontal cortex by disrupting the ventral amygdalofugal and thalamic-frontal pathways as they course through the diencephalon. This case demonstrates that an isolated lesion may cause memory loss without involvement of traditional structures associated with memory and may explain memory disturbances in other white matter disease such as multiple sclerosis and lacunar state.

Aged↗

PubMed1999

Memory bias in obsessive-compulsive disorder (OCD).

There is a memory bias associated with depression, and good reason to expect a memory bias associated with anxiety. However, the results of studies reported to date have been ambiguous. Accordingly, an experiment was conducted to assess memory for contamination in people with different types of anxiety. Memory for contaminated stimuli among participants who met DSM-IV criteria for obsessive-compulsive disorder (OCD) and indicated a fear of contamination (n = 10) was compared to memory in a group of anxious controls (n = 10), and in undergraduate students (n = 20). Participants were shown 50 objects, 25 of which were contaminated by the experimenter and 25 which were touched but not contaminated. They then completed a neuropsychological memory assessment, after which the participants were asked to recall all of the objects touched by the experimenter. They were then asked to approach each object and to rate their anxiety about touching it. Finally, participants were asked about their perceptions of the cleanliness of each object. The OCD group had better memory for contaminated objects than for clean ones. Neither control group showed such a bias. Neuropsychological test scores indicated that this bias is not the result of differences in general memory ability. The results are discussed in terms of the memory-deficit theory of OCD and of behavioural and cognitive approaches to understanding the role of information processing in fear and anxiety.

Adult↗

PubMed2001

Neural correlates of traumatic memories in posttraumatic stress disorder: a functional MRI investigation.

OBJECTIVE: The neuronal circuitry underlying posttraumatic stress disorder (PTSD) was studied in traumatized subjects with and without PTSD. METHOD: Traumatized subjects with (N=9) and without (N=9) PTSD were studied by using the script-driven symptom provocation paradigm adapted to functional magnetic resonance imaging at a 4-T field strength. RESULTS: PTSD subjects showed significantly less activation of the thalamus, the anterior cingulate gyrus (Brodmann's area 32), and the medial frontal gyrus (Brodmann's area 10/11) than did the comparison subjects. CONCLUSIONS: The findings suggest anterior cingulate, frontal, and thalamic involvement in the neuronal circuitry underlying PTSD.

Adult↗

PubMed2007

Impact of emotional salience on episodic memory in attention-deficit/hyperactivity disorder: a functional magnetic resonance imaging study.

BACKGROUND: Patients with attention-deficit/hyperactivity disorder (ADHD) show episodic memory deficits especially in complex memory tasks. We investigated the neural correlates of memory formation in ADHD and their modulation by stimulus salience. METHODS: We recorded event-related functional magnetic resonance imaging during an episodic memory paradigm with neutral and emotional pictures in 12 male ADHD subjects and 12 healthy adolescents. RESULTS: Emotional salience did significantly augment memory performance in ADHD patients. Successful encoding of neutral pictures was associated with activation of the anterior cingulate cortex (ACC) in healthy adolescents but with activation of the superior parietal lobe (SPL) and precuneus in ADHD patients. Successful encoding of emotional pictures was associated with prefrontal and inferior temporal cortex activation in both groups. Healthy adolescents, moreover, showed deactivation in the inferior parietal lobe. CONCLUSIONS: From a pathophysiological point of view, the most striking functional differences between healthy adolescents and ADHD patients were in the ACC and SPL. We suggest that increased SPL activation in ADHD reflected attentional compensation for low ACC activation during the encoding of neutral pictures. The higher salience of emotional stimuli, in contrast, regulated the interplay between ACC and SPL in conjunction with improving memory to the level of healthy adolescents.

Adolescent↗

PubMed2005

Source memory in children with autism spectrum disorders.

The evidence to date regarding memory processes in children with autism spectrum disorders (ASD) remains equivocal. Although children with these neurodevelopmental disorders have been shown to display exceptional memories for fact-based information, they seem to be less able to attach meaning or context to their memories. Thus, this study investigated the specific role of source memory in autism. Children with ASD were compared to a chronological and mental age-matched comparison group of typically developing children. Although children with autism performed similarly to controls on a fact recognition measure, their performance on a source memory task was significantly lower. The findings indicated, however, that the nature of source memory confusion in children with autism does not appear to reflect a generalized deficit in attaching context to memories but rather is dependent on the specific to-be-remembered information that, in this study, involves social aspects of context.

Adolescent↗

PubMed1996

Recall and recognition memory in obsessive-compulsive disorder.

This study examined recall and recognition memory in 20 nonmedicated patients with obsessive-compulsive disorder (OCD) and 20 matched control subjects. As hypothesized, OCD subjects showed abnormalities affecting delayed recall of nonverbal information but showed normal recognition. These results are interpreted as providing preliminary evidence of a nonverbal memory retrieval deficit consistent with proposed corticostriatal system dysfunction in OCD.

Adult↗

PubMed2006

Discrepancy of performance among working memory-related tasks in autism spectrum disorders was caused by task characteristics, apart from working memory, which could interfere with task execution.

Working memory performance has been inconsistently reported in autism spectrum disorders (ASD). Several studies in ASD have found normal performance in digit span and poor performance in digit symbol task although these are closely related with working memory. It is assumed that poor performance in digit symbol could be explained by confirmatory behavior, which is induced due to the vague memory representation of number-symbol association. Therefore it was hypothesized that the performance of working memory task, in which vagueness did not cause confirmatory behavior, would be normal in ASD. For this purpose, the Advanced Trail Making Test (ATMT) was used. The performance of digit span, digit symbol and ATMT was compared between ASD and normal control. The digit span, digit symbol and ATMT was given to 16 ASD subjects and 28 IQ-, age- and sex-matched control subjects. The scores of these tasks were compared. A significantly lower score for ASD was found only in digit symbol compared with control subjects. There were no significant difference in digit span and working memory estimated by ATMT. Discrepancy of scores among working memory-related tasks was demonstrated in ASD. Poor digit symbol performance, normal digit span and normal working memory in ATMT implied that ASD subjects would be intact in working memory itself, and that superficial working memory dysfunction might be observed due to confirmatory behavior in digit symbol. Therefore, to evaluate working memory in ASD, tasks that could stimulate psychopathology specific to ASD should be avoided.

Adult↗

PubMed1995

Memory and amnesia.

Brain damage can cause several distinct disorders of explicit memory as well as several disorders of implicit memory. Organic amnesia is the best studied explicit memory disorder. It is a syndrome that can be caused by lesions in (a) the medial temporal lobes, (b) the midline diencephalon, or (c) the basal forebrain. It remains unresolved whether one or several functional deficits underlie the syndrome, how these deficits should be characterised, and what is the exact location of the causal lesions. There is good evidence that amnesics encode information normally so their deficit(s) must be of storage or retrieval processes. If storage is disrupted, then one would expect item-specific implicit memory for certain kinds of novel information to be disrupted in amnesics. Current evidence is unable to indicate conclusively whether or not this prediction is met mainly because indirect memory test performance depends on explicit as well as implicit memory. Storage deficits should also result in accelerated forgetting in amnesic patients. Studies are described which reveal accelerated loss of free recall, but not recognition, for stories and semantically organised word lists in amnesics at delays between 15 s and 10 min. This suggests that amnesia involves a storage deficit for complex contextual associations that possibly occurs in conjunction with one or more other functional deficits.

Amnesia↗

PubMed2006

Abnormal size of the amygdala predicts impaired emotional memory in major depressive disorder.

BACKGROUND: Amygdala and hippocampus show significant structural abnormalities in major depressive disorder (MDD). Individuals with MDD have difficulties in emotional memory. A relationship between emotional memory deficits and structural abnormalities of amygdala and hippocampus in MDD has been proposed but not shown, yet. METHODS: The current study assessed memory for emotional faces in 21 young women with recent-onset MDD and 23 matched control subjects. All subjects underwent structural magnetic resonance imaging (3D-MRI) and a clinical and neuropsychological assessment. RESULTS: Depressive subjects had significantly enlarged amygdala size and significantly reduced hippocampal size compared with controls. Depressive subjects were significantly impaired in learning emotional facial expressions, with deficits being most pronounced for fearful, surprised and disgusted faces. Depressive subjects with amygdala volumes 1 SD or more above the mean of control subjects showed the strongest impairments. Correlation analyses revealed that larger left amygdala volumes were significantly related to worse memory performance and to higher anxiety scores of depressive subjects. Smaller left hippocampal volumes of depressive subjects were related to higher anxiety scores as well. LIMITATIONS: All MDD subjects were taking antidepressant medication at the time of the study. Longitudinal studies are needed to clarify whether the behavioral and/or volumetric abnormalities of MDD subjects can be attributed to medication or MDD or both. CONCLUSIONS: It might be speculated that amygdala enlargement in young MDD subjects is correlated with amygdalar over-activation and resolves with antidepressant treatment, as was shown for amygdalar over-activation.

Adult↗

PubMed2000

Visuospatial working memory in schizotypal personality disorder patients.

BACKGROUND: Cognitive processing deficits have been identified as an abnormality that schizotypal personality disorder (SPD) individuals share with schizophrenic patients. It has been hypothesized that impaired working memory may be a critical component of several of the more complex cognitive deficits found in schizophrenia spectrum patients. METHOD: 18 DSM-III-R SPD patients, and 17 normal comparison subjects were compared on a pen and paper visuospatial working memory task. Moreover, we identified a second psychiatric comparison group comprised of nine patients with other, non-odd cluster personality disorder diagnoses who met no more than one of the SPD criteria and were also tested on the same task. Each person was given 14 immediate recall trials and 10 trials using a 10 s delay. RESULTS: SPD patients performed significantly worse than normal control subjects on the working memory task. SPD patients also performed significantly worse compared to the non-schizophrenia-related personality disorder psychiatric comparison group. CONCLUSIONS: Like schizophrenic patients, SPD patients demonstrate working memory impairment compared to normal controls. This impairment may be specific to the schizophrenia-related personality disorders.

Adult↗

PubMed2004

Developmental amnesia: a new pattern of dissociation with intact episodic memory.

A case of developmental amnesia is reported for a child, CL, of normal intelligence, who has intact episodic memory but impaired semantic memory for both semantic knowledge of facts and semantic knowledge of words, including general world knowledge, knowledge of word meanings and superordinate knowledge of words. In contrast to the deficits in semantic memory, there are no impairments in episodic memory for verbal or visual material, assessed by recall or recognition. Lexical decision was also intact, indicating impairment in semantic knowledge of vocabulary rather than absence of lexical representations. The case forms a double dissociation to the cases of Vargha-Khadem et al. [Science 277 (1997) 376; Episodic memory: new directions in research (2002) 153]; Gadian et al. [Brain 123 (2000) 499] for whom semantic memory was intact but episodic memory was impaired. This double dissociation suggests that semantic memory and episodic memory have the capacity to develop separately and supports models of modularity within memory development and a functional architecture for the developmental disorders within which there is residual normality rather than pervasive abnormality. Knowledge of arithmetical facts is also spared for CL, consistent with adult studies arguing for numeracy knowledge distinct from other semantics. Reading was characterised by difficulty with irregular words and homophones but intact reading of nonwords. CL has surface dyslexia with poor lexico-semantic reading skills but good phonological reading skills. The case was identified following screening from a population of normal schoolchildren suggesting that developmental amnesias may be more pervasive than has been recognised previously.

Amnesia↗

PubMed2007

Autobiographical memory specificity and emotional disorder.

The authors review research showing that when recalling autobiographical events, many emotionally disturbed patients summarize categories of events rather than retrieving a single episode. The mechanisms underlying such overgeneral memory are examined, with a focus on M. A. Conway and C. W. Pleydell-Pearce's (2000) hierarchical search model of personal event retrieval. An elaboration of this model is proposed to account for overgeneral memory, focusing on how memory search can be affected by (a) capture and rumination processes, when mnemonic information used in retrieval activates ruminative thinking; (b) functional avoidance, when episodic material threatens to cause affective disturbance; and (c) impairment in executive capacity and control that limits an individual's ability to remain focused on retrieval in the face of distraction.

Autobiographies as Topic↗

PubMedDate not supplied

Assessing markers of working memory function in dissociative identity disorder using neutral stimuli: a comparison with clinical and general population samples.

OBJECTIVES: Memory functioning is a central conceptual and phenomenological aspect of dissociative identity disorder (DID). Most empirical work on memory functions in DID has focused on retrieval deficits either within or between dissociated identities. The current study attempted to remedy the scant attention given to working memory functioning. METHOD: In samples representing the DID, non-clinical, depressed, posttraumatic stress disorder (PTSD) and psychosis populations (n = 10 per group), neutral stimuli were used to examine three markers of working memory functioning: one measuring inhibition; one assessing facilitation; and one measuring interference. RESULTS: With the exception of the psychosis sample all groups displayed significant negative priming in the distractor inhibition condition. Facilitation effects were demonstrated by the DID and PTSD groups only. Interference effects were evident in all samples, though the DID and non-clinical groups demonstrated significantly more interference than the psychosis cohort. Distractor inhibition was related to overall schizotypy scores, and dissociation was related to scores in the facilitation condition. CONCLUSIONS: The DID sample displayed a completely distinct functional working memory profile to the psychosis sample when assessed with emotionally neutral stimuli. However, the working memory profile in the DID sample was not entirely dissimilar to the other comparison groups.

Adolescent↗

PubMed1998

Verbal learning and memory in schizotypal personality disorder.

The investigation of cognitive deficits in patients with schizotypal personality disorder (SPD) is important both to establish commonalities between SPD and schizophrenia and to clarify the significance of these cognitive deficits for schizophrenic disorders. The purpose of this study was to examine verbal learning and memory with the California Verbal Learning Test (CVLT) in a group of patients with SPD (n=24) and a group of patients with personality disorders other than SPD (OPD; n=25). The results indicated that SPD patients learned significantly fewer words with practice on the CVLT than OPD patients (F=4.32, df=1,47, p < 0.05), and their rate of learning was reduced relative to normative standards. These findings suggest that SPD patients have a deficit in verbal learning that is similar to, although not as severe as, the impairments seen in schizophrenia.

Adult↗

PubMed2003

Alzheimer disease on speech, language and memory function.

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Alzheimer Disease↗

PubMed2001

Technetium-99m ECD single photon emission computed tomography in brain trauma: comparison of early scintigraphic findings with long-term neuropsychological outcome.

OBJECTIVE: The aim of this study was to assess the prognostic value of early brain scintigraphy in head injury in relation to long-term neuropsychological behavior. Twenty-four patients underwent technetium-99m (Tc-99m) ethyl cysteinate dimer single photon emission computed tomography (SPECT) within 1 month of the trauma. Scintigraphic abnormalities were evaluated both visually and semiquantitatively using the brain-to-cerebellum ratio method. The clinical neuropsychological investigation was conducted to evaluate abnormalities related to motor deficit, frontal behavior, and memory and language disorders. All patients had abnormalities on SPECT scan. One year after trauma, 14 patients (58%) had neuropsychological sequelae. The brain-to-cerebellum ratios in the left basal ganglia and brain stem were significantly decreased in patients with memory disorders (P = .03 and P = .02, respectively). Moreover, SPECT visual analysis indicated that low uptake in the basal ganglia, thalamus, and brain stem was associated with subsequent motor deficit, frontal behavior, and language and memory disorders. The authors conclude that brain SPECT can be valuable in predicting the neuropsychological behavior of survivors of severe head injury.

Adolescent↗

PubMed2006

A prospective study of dysfunctional thinking and the regulation of negative intrusive memories in bipolar 1 disorder: implications for affect regulation theory.

BACKGROUND: Cognitive behavioural therapy (CBT) has been implemented in bipolar (BP) disorder with varying degrees of success. The link between CBT for BP disorder and underlying theory is not clear. There have been attempts to identify a unique style of dysfunctional thinking in BP disorder analogous to that in unipolar (UP) disorder but this has suffered from a dearth of prospective studies controlling for mood and phase of illness. In this prospective study, we have examined whether dysfunctional thinking and the (dys)regulation of traumatic memories are trait vulnerability factors in BP versus UP mood disorders. METHOD: BP-1 and UP groups were followed-up from acute episode to recovery, and compared with a healthy control group. Measures of dysfunctional thinking and linked personality dimensions were taken, together with measures assessing autobiographical memory retrieval (AMT). The presence and control of intrusive memories of traumatic events in BP and UP disorder were assessed. RESULTS: Controlling for mood symptoms and phase of illness, the BP (but not the UP) group was largely indistinguishable from controls on dysfunctional thinking. Intrusive memories of traumatic events were present in 45% of the BP and 48% of the UP groups; and those without intrusions were more overgeneral on the AMT in all phases of illness. CONCLUSION: These findings are in line with the 'affect regulation' hypothesis for UP disorder and deliberate self-harm. This may help in understanding the mode of action of CBT in BP disorder and to further improve the therapy, primarily through the promotion of affective regulation, which is one component of the complex CBT intervention for BP disorder.

Adolescent↗

PubMed2004

Borderline personality disorder: impaired visual perception and working memory.

The neurobiology of borderline personality disorder (BPD) is still elusive. There are a few studies on neuropsychological performance in BPD, which report a broad spectrum of abnormalities. The present study evaluates perception and working memory as instances of basic cognitive functions. Female subjects diagnosed with DSM-IV borderline personality disorder (n=22) were compared with age- and education-matched controls (n=25). Perception speed was assessed by a backward masking paradigm. Working memory was tested by a series of delayed matching-to-sample paradigms involving varying subsidiary functions like mental rotation, retrieval from memory, ignoring distracters, and cross-modal performance. In backward masking, BPD subjects required significantly longer stimulus onset asynchrony (SOA) than controls to identify the visual target, and there was an additional slowing of the motor response. Working memory accuracy was impaired in BPD subjects, but did not worsen when the cognitive load was increased. With increasing task difficulty, they traded off speed for accuracy similarly as the controls. Impulsivity and dissociation ratings were not correlated with performance. It is concluded that perceptional speed and working memory are impaired in BPD, but that the deficits are not augmented by increasing cognitive load.

Adolescent↗