Cognitive impairments of aphasics in picture sorting and matching tasks

Abstract

On the basis of earlier experiments showing a differential deficit of aphasics in picture sorting and matching tasks, two experiments were conducted to test the conjecture of a specific deficit of aphasics in the analytical appraisal of individual features. Broca's and Wernicke's aphasics--according to clinical diagnoses and the Aachener Aphasie Test--were compared with patients having right-hemisphere lesions or left-hemisphere lesions without aphasia. Both groups of aphasics differed from the control groups in the sorting task, irrespective of the sorting criterion, but the differences were small. The picture matching task did not discriminate between groups. Obviously, the basic assumption has to be modified with respect to specific conditions of task requirements. The experimental literature is reviewed.

Is There a Causal Link between the Left Lateralization of Language and Other Brain Asymmetries? A Review of Data Gathered in Patients with Focal Brain Lesions

“…Lupyan and Mirman [ 62 ] systematically tested the link between language defect and categorization impairment by comparing categorization performance in APs and in education-matched normal controls on tasks in which the categorization criterion was either “high-dimensional” (i.e., the objects shared many features, such as “farm animals”) or “low-dimensional” (i.e., the objects shared one or a few features, such as “things that are green”). Aphasic patients were selectively impaired on low-dimensional categorization and their selective impairment was correlated with the severity of their naming impairment, indicating, in agreement with the positions of Cohen et al [ 55 , 56 , 57 , 58 ] that language impairment impacts categorization specifically when that it requires focusing attention and isolating individual features of concepts. Consistent with the same hypothesis were also results of a study in which Pauly et al [ 64 ] tested left or right hemisphere stroke patients on a speeded color discrimination task in which two factors were manipulated: (1) the categorical relationship between the target and the distracters and (2) the visual field in which the target was presented.…”

“…These authors reasoned that one of the main cognitive functions of language consists in analyzing external stimuli focusing attention on their specific features and proposed that non-verbal cognitive defects of APs might be due to a ‘defective analytical isolation of individual features of objects or concepts. Support to this hypothesis came from results obtained on non-verbal matching tasks in which subjects had to decide which of two pictures was more closely related to a third target picture [ 55 , 56 , 57 , 58 ]. In one condition the decision had to be based on the existence of a concrete common situational context, whereas in the other condition it had to be based on the isolation and abstraction of critical features of the depicted objects.…”

Figure-object matching: Another frequent nonverbal impairement of aphasics

“…We were inclined to accept the Cohen group's [9] attribution of the poor nonverbal performance of aphasics on a heterogencons set of perceptual tasks to their inability to build up meaningful, sometimes abstract, links between selected features of stimuli requiring purposeful search. In fact, the critical cues have to be singled out by means of strictly goal-directed inspection.…”