Visual working memory deficits in patients with Parkinson's disease are due to both reduced storage capacity and impaired ability to filter out irrelevant information.
Given that Parkinson's disease broadly affects frontostriatal circuitry, it is not surprising that the disorder is associated with a reduction of working memory. We tested whether this reduction is due to diminished storage capacity or impaired ability to exclude task-irrelevant items. Twenty-one medication-withdrawn patients and 28 age-matched control subjects performed a visuospatial memory task while their electroencephalograms were recorded. The task required them to remember the orientations of red rectangles within the half of the screen that was cued while ignoring all green rectangles. Behavioural and electroencephalogram measures indicated that patients with Parkinson's disease were impaired at filtering out distracters, and that they were able to hold fewer items in memory than control subjects. The results support recent suggestions that the basal ganglia help control access to working memory.
Lee
Eun-Young
EY
Department of Psychological Sciences, University of Missouri, Columbia, MO 65211, USA. eyl7r9@mail.missouri.edu
Cowan
Nelson
N
Vogel
Edward K
EK
Rolan
Terry
T
Valle-Inclán
Fernando
F
Hackley
Steven A
SA
D000368:Aged; D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology*; D016022:Case-Control Studies; D004192:Discrimination, Psychological / Q000502:physiology; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D010775:Photic Stimulation / Q000379:methods; D011237:Predictive Value of Tests; D011601:Psychophysics; D013028:Space Perception / Q000502:physiology*; D013223:Statistics as Topic