Thephonological loopinmedicated patients with Parkinson's disease: presenceofphonological similarity andwordlength effects

Objective-To testtheverbalsubsystem ofBaddeley's workingmemory model (thephonological loop)inpatients with Parkinson's disease. Methods-Fifteen patients withidiopathic Parkinson's disease and15controls were tested withaspanparadigm toassess the effects reflecting thefunctioning ofthe phonological loop:thephonological similarity effect (inverbal andvisual presentation), andthewordlengtheffect (in visual presentation). Resultsand conclusions-The patients didnot show any dysfunction of the phonological loop, reflected bythepresenceofphonological similarity andword length effects, buthadlowerspansthan controls. Theimplications oftheseresults fortheworking memorymodelarediscussed. (7Neurol Neurosurg Psychiatry 1997;62:609-61 1)