Cued recall in anterograde amnesia

After a single presentation of a word list, normal subjects exhibited better retention when prompted with semantic cues than with rhyme or letter cues. Alcoholic Korsakoff patients, patients receiving electroconvulsive therapy (ECT), and the patient N.A. exhibited impaired retention and, unlike control subjects, did not exhibit an advantage of semantic cues over letter and rhyme cues. Two experimental manipulations designed to equate the level of performance of amnesics and controls indicated that these amnesias could be understood as a reflection of weak memory strength that results from deficiencies in initial learning and retention. In addition, alcoholic Korsakoff patients appeared to have greater difficulty utilizing semantic cues than patients receiving ECT or patient N.A.     

A comparison of dichotic and visuo-acoustic competition in hemispherectomized patients

Following hemispherectomy, patients performing dichotic listening tasks have great difficulty reporting items presented to the ear ipsilateral to their intact hemisphere. One possible cause is an attentional imbalance which, when competing inputs are received from both sides of space, restricts the patient's attention to the stimulus contralateral to his remaining hemisphere. If this explanation is true, then a similar ipsilateral ear decrement should occur when a competing visual stimulus is presented in the contralateral field. In the present study, however, hemispherectomy patients easily reported a digit presented to the ear ipsilateral to their intact hemisphere despite the concurrent presentation of a visual digit to their contralateral field.     

Hemispheric alpha asymmetries of stuttering males and nonstuttering males and females for words of high and low imagery

Alpha hemispheric asymmetries of nonstuttering males, nonstuttering females, and stuttering males were explored with electroencephalographic procedures during exposure to two lists of one-syllable words which the subjects were required to recall following presentation. One word list contained low-imagery words while the other contained high-imagery words. Stuttering males were found to have significantly less alpha in their right hemispheres, suggesting right hemispheric processing strategies. This finding was interpreted as supporting the “segmentation dysfunction” explanation of stuttering suggested by Moore and Haynes (1979b). Nonstuttering males showed less left than right alpha while nonstuttering females revealed no difference between their right and left hemispheres. Differences between nonstuttering males and females are discussed as being task and stimuli dependent relative to the segmental/nonsegmental nature of both task and stimuli. Differential hemispheric asymmetries for words of high or low-imagery were not observed.