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Biomedical subjects

Amy Weinstein

Publications and source records attributed to Amy Weinstein.

3 recordsLinked to original sources

Effect of parietal lobe lesions on saccade targeting and spatial memory in a naturalistic visual search task.

The eye movements of two patients with parietal lobe lesions and four normal observers were measured while they performed a visual search task with naturalistic objects. Patients were slower to perform the task than the normal observers, and the patients had more fixations per trial, longer latencies for the first saccade during the visual search, and less accurate first and second saccades to the target locations during the visual search. The increases in response times for the patients compared to the normal observers were best predicted by increases in the number of fixations. In order to investigate the effects of spatial memory on search performance, in some trials observers saw a preview of the search display. The patients appeared to have difficulty using previously viewed information, unlike normal observers who benefit from the preview. This suggests a spatial memory deficit. The patients' deficits are consistent with the hypothesis that the parietal cortex has a role in the selection of targets for saccades, in memory for target location.

Adult↗

Cognitive fatigue during a test requiring sustained attention: a pilot study.

BACKGROUND: Fatigue is common in multiple sclerosis (MS), but difficulty quantifying fatigue severity has impeded studies of its characteristics, mechanisms, and therapeutics. Motor fatigue can be objectively measured as the decline in strength occurring during sustained contractions. Analogous declines in cognitive performance occur during tasks requiring sustained attention. OBJECTIVE: To objectively measure cognitive fatigue as a decline in performance during tests requiring sustained attention. DESIGN/METHODS: Patients with clinically stable MS (n = 20) and healthy controls (n = 21) with comparable age, gender, and education completed the Paced Auditory Serial Addition Test (PASAT) and the Digit Ordering Test (DOT) at two identical test sessions separated by 4-10 days, within a month after two practice sessions. Cognitive fatigue was quantified with two pre-specified methods for each test. The reliability of cognitive fatigue assessments was evaluated with intraclass correlation coefficients (ICCs) and construct validity was evaluated using correlations with measures of self-reported fatigue, cognition, and overall impairment/disability. RESULTS: MS patients had an average of 18.7 items correct on the first 20 items of the PASATand 17.8 correct on the last 20 items, quantified as 5.3-5.8% declines in performance using the different measurement methods (P = 0.01, rejecting the null hypothesis of zero mean decline). Although MS patients as a group demonstrated a similar decline at both sessions, ICCs were relatively low. Control patients did not demonstrate significant declines in performance during PASAT administration, but tests comparing declines in MS patients and controls did not demonstrate significant differences. Fatigue was not demonstrated using the DOT, and test-retest reliability was very poor. CONCLUSIONS: MS patients have objectively measurable cognitive fatigue during administration of the PASAT.

Adolescent↗

Minimal neuropsychological assessment of MS patients: a consensus approach.

Cognitive impairment is common in multiple sclerosis (MS), yet patients seen in MS clinics and neurologic practices are not routinely assessed neuropsychologically. In part, poor utilization of NP services may be attributed to a lack of consensus among neuropsychologists regarding the optimal approach for evaluating MS patients. An expert panel composed of neuropsychologists and psychologists from the United States, Canada, United Kingdom, and Australia was convened by the Consortium of MS Centers (CMSC) in April, 2001. Our objectives were to: (a) propose a minimal neuropsychological (NP) examination for clinical monitoring of MS patients and research, and (b) identify strategies for improving NP assessment of MS patients in the future. The panel reviewed pertinent literature on MS-related cognitive dysfunction, considered psychometric factors relevant to NP assessment, defined the purpose and optimal characteristics of a minimal NP examination in MS, and rated the psychometric and practical properties of 36 candidate NP measures based on available literature. A 90-minute NP battery, the Minimal Assessment of Cognitive Function in MS (MACFIMS), emerged from this discussion. The MACFIMS is composed of seven neuropsychological tests, covering five cognitive domains commonly impaired in MS (processing speed/working memory, learning and memory, executive function, visual-spatial processing, and word retrieval). It is supplemented by a measure of estimated premorbid cognitive ability. Recommendations for assessing other factors that may potentially confound interpretation of NP data (e.g., visual/sensory/motor impairment, fatigue, and depression) are offered, as well as strategies for improving NP assessment of MS patients in the future.

Cognition Disorders↗