Nonverbal Memory Tasks Research Articles

Recognition deficits resulting from focussed attention in aphasia.

Two nonverbal short-term memory tasks, a Picture Recognition and a Paired Association Task, were performed by matched groups of aphasics and brain-damaged controls (N=52 each). For both tasks the alternatives on the answer forms differed systematically on three dimensions, one of which had been highlighted experimentally for each item before the target picture was indicated. In both tasks aphasics made more errors than braindamaged controls only with respect to those features that had been stressed beforehand; they were less able than controls to take advantage of focussed attention. The number of these errors was correlated with performance in the Token Test, a picture naming and a word comprehension task.

Memory Function in Focal Epilepsy: A Comparison of Non-Surgical, Unilateral Temporal Lobe and Frontal Lobe Samples

Three well-matched groups of non-surgical, pharmacologically controlled epileptic patients with unilateral seizure foci in either the left temporal lobe, the right temporal lobe or a frontal lobe, and a normal control group were compared on several verbal and non-verbal memory tasks. Results revealed significant impairment of verbal memory in left temporal epileptic subjects, and significant impairment of non-verbal, visual memory in right temporal epileptic subjects. Seizure patients with unilateral frontal lobe foci did not differ from the control sample on any measure. Results support previous research which emphasizes the importance of temporal lobe systems in memory function. The findings are discussed with regard to the nature and specificity of the observed deficits.

The specificity of intrahemispheric EEG alpha coherence asymmetry related to psychological task

Male right handed subjects performed two parallel verbal and nonverbal memory tasks, known to be associated with the anterior temporal lobe, while EEG was recorded from temporal sites referred to either F z or to linked mastoids. Intrahemispheric coherence and power in the alpha band were calculated. Coherence effects were observed, independent of reference site, which associated the right hemisphere and nonverbal tasks with increased coherence. These effects appear to be relatively specific to more anterior temporal electrode pairs, and confirm previous findings. Power effects demonstrated the difficulty of assessing task-dependent changes independent of reference site, and suggested that specific alpha enhancement may be observed with task involvement. The contribution of coherence analysis to the study of cerebral organisation is discussed.

Material-specific memory deficits in alcoholic Korsakoff patients

The short-term memory disorders of alcoholic Korsakoff patients were examined for material- and modality-specific deficits. Verbal and non-verbal memory tasks employing the visual, auditory, and tactile modalities were administered to Korsakoff patients and to alcoholic and non-alcoholic control subjects. In all three modalities the Korsakoff patients demonstrated normal short-term retention of non-verbal materials but severe memory deficits for verbal materials. These findings are consistent with the hypothesis that failures in verbal encoding underlie these patients' memory difficulties.