The Influence of refractoriness upon comprehension of non-verbal auditory stimuli.
An investigation of non-verbal auditory comprehension in two patients with global aphasia following stroke is reported. The primary aim of the investigation was to establish whether refractory access disorders can affect non-verbal input modalities. All previous reports of refractoriness, a cognitive syndrome characterized by response inconsistency, sensitivity to temporal factors and insensitivity to item frequency, have involved comprehension tasks which have a verbal component. Two main experiments are described. The first consists of a novel sound-to-picture and sound-to-word matching task in which comprehension of environmental sounds is probed under conditions of semantic relatedness and semantic unrelatedness. In addition to the two stroke patients, the performance of a group of 10 control patients with non-vascular pathology is reported, along with evidence of semantic relatedness effects in sound comprehension. The second experiment examines environmental sound comprehension within a repetitive probing paradigm which affords assessment of the effects of semantic relatedness, response consistency and presentation rate. It is demonstrated that the two stroke patients show a significant increase in error rate across multiple probes of the same set of sound stimuli, indicating the presence of refractoriness within this non-verbal domain. The implications of the results are discussed with reference to our current understanding of the mechanisms of refractoriness.
Crutch
Sebastian J
SJ
Department of Neurodegeneration, Dementia Research Centre, Institute of Neurology, University College London, London, UK. s.crutch@drc.ion.ucl.ac.uk
Warrington
Elizabeth K
EK
D000161:Acoustic Stimulation; D000368:Aged; D000818:Animals; D001037:Aphasia / Q000503:physiopathology*; D003071:Cognition; D032882:Comprehension; D005260:Female; D006309:Hearing; D006801:Humans; D007807:Language Tests; D008297:Male; D012033:Refractory Period, Psychological; D012660:Semantics