High Speed Memory Scanning in Parkinsonism

Abstract

This study tested the hypothesis that the slowing seen in parkinsonism includes cognitive as well as motoric components. The sample consisted of 20 nondemented parkinsonian patients, group matched to 16 normals by age, education, and verbal IQ. Each group was divided into young (64 and under) and old (65 and over) subsets. The Sternberg character classification paradigm was used to measure the speed and accuracy of one cognitive function, short term memory scanning. Following a logarithmic transformation of the reaction time data, scanning speed was found to be increased, but only for the elderly patients (p = .01). Scanning accuracy was normal for both patient groups. These findings suggest that at least one cognitive function, the scanning of elements held in short term memory, is slowed in parkinsonism. This mnemonic slowing, like bradykinesia, is seen primarily in elderly parkinsonian patients. It is not readily explained as a motor phenomenon, as part of a generalized mnemonic or intellectual deficit, or as an artifact secondary to periodic extreme reaction times. The term bradyphrenia, used in early descriptions of parkinsonism, may be an apt descriptor of this deficit.

Neurobehavioral functions among workers exposed to manganese ore.

“…These impairments include slowed scanning on a visual recognition task (26) and slowing on motor response tasks that can reflect both bradykinesia and a central defect of motor programming (24). Mortimer et al (27) and Pirozzolo et al (28) observed that, among parkinsonism patients, bradykinesia correlated significantly with poorer performances on tests involving psychomotor speed, visual-spatial performances, and memory for spatial orientation.…”

Cognitive dysfunction and dementia in Parkinson?s disease

“…The most consistent findings in patients with PD are deficits of working memory (Owen, 1993;Cooper, 1993Cooper, , 1992Bradley, 1989;Wilson, 1980) and explicit memory (Buytenhuijs, 1994;Taylor, 1990Taylor, , 1986. Working memory can be defined as the ability to hold internal representations in short-term memory and to manipulate this mnemonic information on line to enable adaptive behaviour to be based on these representations rather than on immediate stimuli (Goldman-Rakic, 1987).…”

Disentangling the Role of Cortico-Basal Ganglia Loops in Top–Down and Bottom–Up Visual Attention: An Investigation of Attention Deficits in Parkinson Disease

“…Mounting evidence indicates that PD, apart from the typical motor signs (Lang & Lozano, 1998;Gibb & Lees, 1988), is often accompanied by a variety of cognitive deficits (Caballol, Marti, & Tolosa, 2007;Pirozzolo, Hansch, Mortimer, Webster, & Kuskowski, 1982;Reitan & Boll, 1971), including rather subtle difficulties in visual-spatial perception (Boller et al, 1984), memory (Flowers & Robertson, 1985;Wilson, Kaszniak, Klawans, & Garron, 1980), language (Matison, Mayeux, Rosen, & Fahn, 1982), concept formation, and behavioral regulation (Flowers & Robertson, 1985;Cools, van den Bercken, Horstink, van Spaendonck, & Berger, 1984;Lees & Smith, 1983;Bowen, Kamienny, Burns, & Yahr, 1975), which suggests the involvement of the BG and the cortico-subcortical loops of which they are part in the regulation of these cognitive functions.…”