Biomedical subjects

E A Phelps

Publications and source records attributed to E A Phelps.

5 recordsLinked to original sources

PubMed1992

Hemispheric differences in mnemonic processing: the effects of left hemisphere interpretation.

Several studies suggest that the abilities to make inferences and interpret events are stronger in the left hemisphere than the right hemisphere (Gazzaniga, M. S., The Social Brain. Basic Books, New York, 1985). Given that inference and interpretation are important aspects of normal memory functioning (Bartlett, F. C., Remembering: A Study in Experimental and Social Psychology, Cambridge University Press, 1932), one would expect this hemispheric difference to extend to mnemonic processing. Two split brain subjects were shown a series of pictures representing a common scene. Their memory for these pictures was later tested with a lateralized Yes-No recognition test where the distractor pictures were either consistent or inconsistent with the scene. The left hemisphere performed below chance on consistent distractor pictures whereas the right hemisphere was above chance on these pictures and performed at the same level of accuracy as the pictures originally presented. These results suggest that recognition performance in the left hemisphere was more strongly influenced by the expectations for actions common to a scene than the right hemisphere and provide evidence that the left hemisphere superiority in interpretation and inference effect memory performance.

Attention↗

PubMed1988

Amnesia and second language learning.

The ability of an anterograde amnesic C.S. to learn a second language is assessed. First, her claim that she learned Italian while amnesic was examined in a series of formal tests of Italian. Second, C.S. and her husband were tutored in French and her acquisition was compared to that of her husband's. Third, C.S.'s ability to learn other kinds of verbal material with practice was investigated. The implications of C.S.'s apparent ability to learn a second language in the presence of a severe deficit for memory for other kinds of verbal material is discussed.

Amnesia↗

PubMed1988

More on recognition and recall in amnesics.

Hirst et al. (1986) reported that amnesic forced-choice recognition was relatively preserved when compared with amnesic recall. They equated normal recognition and amnesic recognition by extending exposure time for the amnesics and then comparing amnesic recall and normal recall. Amnesic recall was worse than normal recall, despite equated recognition. We conducted two experiments to extend that result. Experiment 1 established that the findings of Hirst et al. are not paradigm specific and hold when amnesic recognition and normal recognition are equated by increasing the retention interval for normals. In Experiment 2 we further established the generality of the result by examining yes-no recognition. Findings further specify the selective nature of the direct memory deficit in amnesics.

Amnesia↗

PubMed1986

Recognition and recall in amnesics.

Although there is considerable agreement that performance in direct memory tasks (e.g., recall, recognition) is more disrupted by amnesia than performance in indirect memory tasks (e.g., mirror reading, word completion), one may be able to further circumscribe the deficit within the domain of direct memory tasks. The present article explores whether recall is disproportionately disrupted by amnesia compared to recognition. If amnesia affects memory uniformly across different direct memory measures, recall of normal controls should not differ from the recall of amnesics when recognition scores of these two groups are equated. On the other hand, if recall is disproportionately disrupted, normal recall should be superior to amnesic recall even when recognition is equated. The present study equated amnesic recognition with that of controls by providing amnesics with 8 s of study time and normal subjects with 0.5 s. Amnesics with Korsakoff's syndrome, amnesics with other etiologies, and appropriate controls were examined. Normal recall was superior to amnesic recall even when no differences were found in recognition. The results further specify the selective nature of amnesia.

Alcohol Amnestic Disorder↗

PubMedDate not supplied

Deficits in recall following partial and complete commissurotomy.

There have been reports in the literature of both impaired (Zaidel and Sperry, 1974) and intact (LeDoux et al., 1977) memory performance following callosotomy. In the present article, memory is examined in patients who received either partial or complete callosotomy in an effort to determine (1) if there is a memory deficit following callosotomy, (2) if certain types of callosotomy are more likely to lead to a deficit (i.e., anterior vs posterior), and (3) if there is a global memory deficit or if some mnemonic functions are affected more than others. Patients receiving either partial or complete section of the corpus callosum were examined pre- and postoperatively on standardized memory tests and tests of recall and recognition. In addition, two patients with complete callosotomy and matched control subjects were given tests of verbal recall and recognition. A deficit in both visual and verbal recall was found in patients with posterior section, but not those receiving anterior section. No impairment was found on tests of verbal recognition for any patients. Posterior callosal section generally includes the hippocampal commissure and other hippocampal connections, while anterior sectioning does not. Given the known importance of the hippocampus (Milner, 1970) and the differences between recall and recognition memory (Bransford and Johnson, 1972) in normal memory functioning, several hypotheses are proposed as to why these results might be expected.

Adult↗