Groups of patients with idiopathic Parkinson's disease, either medicated or unmedicated, were compared with matched groups of normal controls on a computerized battery previously shown to be sensitive to frontal lobe dysfunction, including tests of planning, spatial working memory and attentional set-shifting. In a series of problems based on the 'Tower of London' test, medicated patients with Parkinson's disease were shown to be impaired in the amount of time spent thinking about (planning) the solution to each problem. Additionally, an impairment in terms of the accuracy of the solution produced on this test was only evident in those patients with more severe clinical symptoms and was accompanied by deficits in an associated test of spatial short-term memory. Medicated patients with both mild and severe clinical symptoms were also impaired on a related test of spatial working memory. In contrast, a group of patients who were unmedicated and 'early in the course' of the disease were unimpaired in all three of these tests. However, all three Parkinson's disease groups were impaired in the test of attentional set-shifting ability, although unimpaired in a test of pattern recognition which is insensitive to frontal lobe damage. These data are compared with those previously published from a group of young neurosurgical patients with localized excisions of the frontal lobes and are discussed in terms of the specific nature of the cognitive deficit at different stages of Parkinson's disease.

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Fronto-striatal cognitive deficits at different stages of parkinson's disease

The functional emergence of prefrontally-guided working memory systems in four- to eight-year-old children

Several tests from the CANTAB neuropsychological test battery previously shown to be sensitive to frontal lobe dysfunction were administered to a large group of normal volunteers (N = 341) ranging in age from 21 to 79 years The main tests included a computerized form of the Tower of London test of planning, a self-ordered spatial working memory task, and a test of attentional set formation and shifting A computerized form of the Corsi spatial span task was also given Age-related graded declines in performance were seen, sometimes in a discontinuous manner, especially for the attentional set shifting task (at the extradimensional shift stage) Patterns of deficits reminiscent of frontal lobe or basal ganglia damage were observed in the oldest age group (74–79) However, overall the data were only partially consistent with the hypothesis that frontal lobe functions are the most sensitive to effects of aging Factor analyses showed that performance in the executive tests was not simply related to a measure of fluid intelligence, and their performance had a factor loading structure distinct from that for the CANTAB tests of visual memory and learning previously administered to the same sample Finally, only limited support was found for the hypothesis that cognitive aging depends on slowed information processing (JINS, 1998, 4, 474–490)

/pdf/a-study-of-performance-on-tests-from-the-cantab-battery-56cejigla4.pdf

A study of performance on tests from the CANTAB battery sensitive to frontal lobe dysfunction in a large sample of normal volunteers: Implications for theories of executive functioning and cognitive aging

An analysis is provided of three distinct paradigms that have been used to study executive functions of the prefrontal cortex involving planning, self-ordered memory or attentional set-shifting. Psychological and anatomical dissociations are sought from the perspective of studies of patients with frontal lobe lesions, functional neuroimaging, psychometric studies in normal volunteers and experimental studies in non-human primates. Particular attention is paid to attempts to dissociate mnemonic from other executive capacities. Thus, patients with frontal damage are shown to have deficits in their (1) use of strategies to improve performance in a spatial working memory task and (2) capacity to make an extra-dimensional shift due to a high-order failure of inhibition in an attentional set-shifting paradigm. These results are discussed in terms of anatomical and neuropharmacological dissociations of different aspects of executive function within the prefrontal cortex shown in monkeys.

Dissociating executive functions of the prefrontal cortex.

Visuo-spatial short-term recognition memory and learning after temporal lobe excisions, frontal lobe excisions or amygdalo-hippocampectomy in man.

Alzheimer''s disease (AD) is characterized by marked cognitive and especially mnemonic decline. Microcomputer controlled tests offer a powerful method for assessing these impairments, since precise control over stimulus presentation and responding can be achieved. The recently described CANTAB© (Cambridge Neuropsychological Test Automated Battery) procedure includes a number of visual tasks which can help to pinpoint these deficiencies with accuracy. Using some of the tests available, we describe impairments in nonverbal visual recognition, memory and learning seen in AD.

Detection of Visual Memory and Learning Deficits in Alzheimer's Disease Using the Cambridge Neuropsychological Test Automated Battery

Detection of visual memory and learning deficits in Alzheimer's disease using the Cambridge neuropsychological test automated battery

Visuospatial memory was studied in patients suffering from senile dementia of the Alzheimer type (SDAT). They had been allocated into one of two groups depending on the severity of their disorder (mild or moderate), and a control group of healthy elderly subjects was included. Three different microcomputer-controlled tasks were used. The spatial span task was able to distinguish between the two SDAT groups. Both groups were impaired, relative to control, on spatial recognition. The deficit in spatial working memory was also equivalent in the mild and moderate groups and was accompanied by evidence of an intact strategic approach to the task. The normal positive relationship between spatial memory performance and strategy was in fact reversed in the SDAT groups, suggesting a pure spatial memory deficit. These results show that spatial memory processes are impaired in the early stages of SDAT and get worse as the disease progresses. They also suggest that the neuroanatomical foci of the deficits may be predominantly in posterior cortical regions (including hippocampus), rather than the frontal cortex.

Catherine J. Wray

Papers

Detection of Visual Memory and Learning Deficits in Alzheimer's Disease Using the Cambridge Neuropsychological Test Automated Battery

Detection of visual memory and learning deficits in Alzheimer's disease using the Cambridge neuropsychological test automated battery

Does visuospatial memory in senile dementia of the Alzheimer type depend on the severity of the disorder