Biomedical subjects

M W Haut

Publications and source records attributed to M W Haut.

14 recordsLinked to original sources

PubMed2001

Neural activation during frequency-memory performance.

Lesion studies have demonstrated that frequency memory, or memory for the frequency of occurrence, is associated with prefrontal and not temporal lobe lesions. This study examined neural activation during performance on a frequency-memory-judgment task and a recognition-memory task, both using words. Relative to a control task, the authors observed peaks of activation during frequency-memory performance in the left ventrolateral prefrontal cortex (BA 45) and other areas typically associated with working memory (dorsolateral prefrontal cortex, posterior parietal cortex). Recognition performance was associated with activation in the same left ventrolateral prefrontal location as was observed with frequency memory. When comparing activation during frequency memory with activation during recognition memory, the authors found a suppression of activation in the hippocampus bilaterally during frequency memory. This study supports a neuroanatomical distinction between frequency and recognition memory.

Adult↗

PubMed2000

Verbal working memory and solvent exposure: a positron emission tomography study.

Neuropsychological studies have documented frontal dysfunction in patients with a history of exposure to organic solvents. The deficits typically observed in these patients appear to be related to working memory (WM). This study used [15O] water positron emission tomography (PET) to examine the pattern of neural activation during verbal working memory in patients with a history of exposure to solvents. Six individuals with solvent exposure were compared with 6 age- and education-matched controls. On the 2 WM tasks examined with PET, with equivalent task performance, participants with solvent exposure demonstrated frontal peaks that were atypical for the tasks, whereas the posterior peaks were typical for the tasks. The results support frontal dysfunction and compensatory use within anterior regions of the WM system in patients with solvent exposure.

Brain↗

PubMed2000

Neural activation during performance of number-letter sequencing.

Recent advances in neuroimaging have enabled researchers to establish relatively specific areas of the brain that are involved in working memory. In this positron emission tomography study we examined the pattern of neural activation associated with performance on number-letter sequencing, a purported measure of working memory included in the new Wechsler scales for memory and intelligence. After controlling for basic audition, verbalization, and attention, areas of activation were observed in the orbital frontal lobe, dorsolateral prefrontal cortex, and posterior parietal cortex. This is highly consistent with reports from the literature on activation patterns associated with working memory. More activation peaks were observed in the right hemisphere, suggesting the participants utilized visualization of the verbal information. Consistent with task conceptualization, this study provides support for number-letter sequencing as a task involving working memory.

Adult↗

PubMed2000

Clinical features of chronic subdural hematoma: neuropsychiatric and neuropsychologic changes in patients with chronic subdural hematoma.

This article provides a background review of the cognitive and behavioral symptoms associated with chronic subdural hematoma (CSH). The areas addressed include the initial cognitive and behavioral symptom presentation, lateralization and localizing signs, differences between older and younger patients, and differential diagnosis. Although it is clear that behavioral and cognitive abnormalities are seen in CSH, further work is needed to objectively clarify the range of symptoms and signs.

Dementia↗

PubMed1999

Neurobehavioral effects of acute exposure to inorganic mercury vapor.

Mercury has well-established toxic effects on the central nervous system. This article describes comprehensive neuropsychological and emotional functioning of a group of 13 workers exposed to inorganic mercury vapor compared to that of a normal control group. The exposed group was exposed over a 2- to 4-week period and had elevated blood mercury levels. The evaluations were conducted between 10 and 15 months after exposure was terminated. Observed cognitive deficits included impairment in the following domains: motor coordination, speeded processing with and without a motor component, cognitive flexibility, verbal fluency, verbal memory, and visual problem solving and conceptualization. Emotional problems included increased focus on physical functioning, depression, anxiety, and social withdrawal. Cognitive deficits were, for the most part, not significantly associated with the degree of depression present.

Acute Disease↗

PubMed1996

On the nature of Wisconsin Card Sorting Test performance in schizophrenia.

Performance on the Wisconsin Card Sorting Test (WCST) is widely reported to be impaired in patients with schizophrenia. It has been hypothesized that the performance deficit on the WCST in schizophrenia is related to a dysfunction of the frontal lobe, specifically the dorsolateral prefrontal cortex. This hypothesis was tested by comparing a group of patients with schizophrenia to patients with low grade right or left frontal lobe tumors and a group of patients with non-frontal high grade tumors. The results demonstrated a remarkable similarity in performance on the WCST between patients with schizophrenia and patients with right frontal lobe tumors. Patients with left frontal lobe tumors, non-frontal tumors, and normal control subjects did not show the same pattern of performance. This study provides support for frontal lobe dysfunction in the symptomatology of schizophrenia.

Adult↗

PubMed1996

Neuropsychological functioning in a patient with paraneoplastic limbic encephalitis.

A 54-year-old woman with clinically diagnosed paraneoplastic limbic encephalitis secondary to adenocarcinoma of the lung is described. Neuropsychological evaluation revealed intact visual perception, visual construction, language, speeded processing, and verbal abstract reasoning in the presence of a severe anterograde amnesia for both verbal and visual information. A profound consolidation problem is discussed in view of other diseases of the mesial temporal lobes resulting in impaired consolidation of new material.

Adenocarcinoma↗

PubMed1994

The establishment of clinical cutoffs in measuring caregiver burden in dementia.

Although several scales have been developed to assess burden, their clinical utility has been limited by the absence of relevant cutoff points. Clinical data from 140 primary caregivers seeking a dementia evaluation for a family member were analyzed to establish the psychometric properties of a caregiver burden screen. Results indicate that the cutoff values were both sensitive and specific to negative caregiving outcomes. These findings suggest that use of a burden screen may assist clinicians when assessing the adequacy of caregiving arrangements in dementia.

Aged↗

PubMed1992

Gist recall in multiple sclerosis.

This study examined gist recall (memory for important story ideas) in patients with multiple sclerosis. Twelve patients with clinically probable or definite multiple sclerosis and 10 neurologically intact control subjects were read prose passages from the Wechsler Memory Scale-Revised Logical Memory subtest. The idea units from these passages contained low, medium, and high information content to the stories. In comparison with the control subjects, the patients recalled fewer total elements over immediate and delayed conditions. However, similar to controls, they recalled more ideas that were of high rather than low or medium importance. These results suggest that semantic sensitivity to important ideas of narratives is a relatively preserved feature in multiple sclerosis.

Adult↗

PubMed1992

Clinical assessment of family caregivers in dementia.

Development of an integrated family assessment inventory based on the Double ABCX and Circumplex models of family functioning and its clinical utility was evaluated with 121 primary family caregivers from a cognitive disorders program. The proposed model predicted a significant proportion of the variance associated with caregiver stress and strain. Several aspects of the caregiving arrangement also emerged as key features in predicting caregiver depression. These findings supported the model's central premise that both dyadic (caregiver-patient) and systemic (caregiver-family) variables are salient in assessing the impact of family caregiving with dementia.

Activities of Daily Living↗

PubMed1991

The psychological treatment of memory impairment: a review of empirical studies.

Memory impairment is a frequent effect of many different forms of brain dysfunction. Memory impairment is also a frequent focus of treatment interventions, and there have been many different treatment methods suggested. The suggested methods include direct retraining, the use of spared skills in compensating for the impairment (alternate functional systems), and the use of behavioral strategies to circumvent the manifest memory dysfunction (behavioral prosthetics). Unfortunately, there are very few studies comparing the various suggested treatment methods. The present paper evaluates the empirical evidence related to the treatment of memory dysfunction and suggests directions for future investigations. Although the evidence is not conclusive, it appears that some forms of treatment may be helpful in remediating certain types of memory impairment. An approach likely to be productive would include some consideration of the impaired neurological and psychological mechanisms responsible for the manifest memory deficit as well as a consideration of the etiology of the injury thought to be causally related to the memory deficit. As yet, there have been no rigorous empirical evaluations of these considerations.

Amnesia↗

PubMed1991

Speed of processing within semantic memory following severe closed head injury.

This study investigated the effects of severe closed head injury (CHI) on the speed of information processing within semantic categories. The question of whether subjects were able to benefit from priming was also investigated. Survivors of severe CHI who were less than 1 year postinjury and survivors who were greater than 1 year postinjury were compared with neurologically normal matched controls utilizing a category judgement task. The results demonstrated slower processing within semantic memory for both groups of CHI patients compared to normal controls. Furthermore, individuals with CHI were able to benefit from priming to the same relative degree as control subjects. Overall, the results suggested semantic organization remains intact after severe CHI, but accessing semantic information is slowed.

Adult↗

PubMedDate not supplied

The recall of prose as a function of importance following closed head injury.

Closed head injury (CHI) results in significant memory dysfunction. Although the disabling aspects of memory impairment after CHI have been recognized, little attention has been focused on the theoretical nature of these memory problems. A means of examining semantic sensitivity to the importance of the ideas presented in the Wechsler Memory Scale-Revised Logical Memory subtest was developed. Subjects with CHI were sensitive to the semantic structure of the stories, but lost more important information at a faster rate than controls. Differences in recall, dependent on the passage, suggested that the two stories in the Wechsler Memory Scale-Revised are not equivalent.

Adult↗

PubMedDate not supplied

Coping and family functions after closed head injury.

Cognitive deficits associated with closed head injury (CHI) have been well studied. Less attention has been directed to the emotional consequences of CHI and subsequent attempts to cope with major life events. CHI typically constitutes a catastrophic injury, yet few studies have examined coping strategies used by individuals after CHI or the effects of CHI on family functioning that may mediate coping. Previous workers have speculated that time since injury is a crucial determinant of coping; however, this has not been investigated with regard to CHI. In this preliminary investigation, 40 patients with CHI were compared with 17 neurologically intact controls. The CHI group was divided into two groups according to time since injury. It was found that patients with CHI used information seeking as their most dominant coping strategy regardless of their time since injury. Patients with CHI had higher family cohesion scores than control subjects. Implications of these findings for psychological response to CHI are discussed.

Adaptation, Psychological↗