A Comparative Study of Visuospatial Memory and Learning in Alzheimer-Type Dementia and Parkinson's Disease

Abstract

Groups of patients with dementia of Alzheimer type (DAT) and idiopathic Parkinson's disease, together with age and IQ-matched normal controls, were compared on several computerized tests of visuospatial memory and learning. Two different groups of parkinsonian patients were studied: (1) a newly diagnosed group, early in the course of the disease, not receiving medication (NMED) PD) and (2) a group later in the course of the disease, receiving medication (MED PD). The DAT and MED PD group were significantly impaired in both spatial and visual pattern recognition memory. The DAT group exhibited a delay-dependent deficit (over 0-16 s) in a delayed matching-to-sample procedure, but were not impaired at simultaneous-matching-to-sample. By contrast, the MED PD group showed delay-independent deficits in the delayed matching-to-sample test and both the MED PD and the NMED PD group were also significantly impaired in simultaneous matching. In a form of delayed response test, the subjects were required first to memorize and then to learn the locations of several abstract visual stimuli which varied progressively in number from 1 to 8. The DAT group were severely impaired in this conditional associative learning task. A significant proportion of patients, but none of the controls, in the NMED and MED PD group also failed the test at the levels of 6 or 8 items. There was a significant correlation between the performance on the first trial, memory score in the delayed response task and indices of clinical disability and disease duration in the patients with Parkinson's disease. The results are discussed in terms of the utility of the comparison between DAT and PD in characterizing the nature of the cognitive deficits in these conditions and their relation to those findings from animal neuropsychology which use comparable paradigms.

Effects of brief time delays on matching-to-sample abilities in capuchin monkeys (Sapajus spp.)

“…Moreover, the difference observed between old and young monkeys could not be reduced by providing the monkeys with extensive training on the task [57]. In elderly humans, and most severely in those affected by Alzheimer's disease, DMTS tasks revealed a similar delay-dependent impairment [56,58]. In some cases, patients with dementia failed to solve even 0-dealy DMTS tasks [59].…”

Profiles of Cognitive Dysfunction in Chronic Amphetamine and Heroin Abusers

“…These tests assess visual pattern and visuospatial recognition memory (Sahakian et al 1988). In the pattern recognition task, which is more sensitive to temporal than frontal lobe dysfunction (Owen et al 1995b), subjects were presented with a successive series of twelve colored abstract patterns.…”

“…Tests shown to be sensitive to fronto-striatal or temporal lobe damage were employed from a standardized and computerised neuropsychological test battery (CANTAB) (Robbins et al 1994 together with other related variants (Iddon et al 1998;Owen et al 1995a). The CANTAB battery has been used in a wide variety of relevant patient groups, including patients with neurosurgical excisions of the prefrontal cortex or temporal lobe (Owen et al 1995b), basal ganglia disorders such as Parkinson's (e.g., Downes et al 1989;Owen et al 1992), and Huntington's disease (e.g., Lawrence et al 1996), as well as depression, schizophrenia (Elliott et al 1998), and dementia (Sahakian et al 1988). The battery has also been previously employed in psychopharmacological Elliott et al 1997;Robbins et al 1998) and toxicological (Maruff et al 1998) investigations.…”

Time of day and caffeine influence some neuropsychological tests in the elderly.

“…associative memory (Sahakian et al, 1988) (McKenna & Warrington, 1980) and requires the participant to name 30 displayed objects.…”