Right-Hemisphere Memory Superiority: Studies of a Split-Brain Patient

@article{Metcalfe1995RightHemisphereMS,
  title={Right-Hemisphere Memory Superiority: Studies of a Split-Brain Patient},
  author={Janet Metcalfe and Margaret G. Funnell and Michael S. Gazzaniga},
  journal={Psychological Science},
  year={1995},
  volume={6},
  pages={157 - 164}
}
Six experiments explored hemispheric memory differences in a patient who had undergone complete corpus callosum resection The right hemisphere was better able than the left to reject new events similar to originally presented materials of several types, including abstract visual forms, faces, and categorized lists of words Although the left hemisphere is capable of mental manipulation, imagination, semantic priming, and complex language production, these functions are apparently linked to… 

Figures and Tables from this paper

Visual grouping and the right-hemisphere interpreter
Abstract Four decades of research with callosotomy—or “split-brain”—patients have revealed dramatic functional asymmetries between the cerebral hemispheres. The most striking hemispheric differences
Hemispheric asymmetries in the time course of recognition memory
TLDR
The ubiquitous advantage of the left hemisphere for the processing and retention of verbal information is attenuated and perhaps even reversed over long retention intervals, consistent with theories that propose differences in the degree to which the hemispheres maintain veridical versus semantically transformed representations of the input they receive.
Hemispheric Asymmetries in Verbal Memory
Publisher Summary Studies of cerebral asymmetries identify the functions of individual hemispheres to better understand how they cooperate during normal processing. Although the two cerebral
Remembering 1500 pictures: The right hemisphere remembers better than the left
TLDR
Images that were presented initially to the right hemisphere were better recognized than those presented to the left hemisphere, consistent with previously described hemispheric differences in the memory of split-brain patients.
Hemispheric Encoding Asymmetry is More Apparent Than Real
TLDR
Convergent with recent neuroimaging studies, these results with split-brain patients suggest that these hemispheric differences are not due to unique specializations in each half brain for encoding memories, but rather, are due to preferential recruitment of the synaptically closer prefrontal cortex to posterior regions processing material-specific information.
Hemispheric asymmetries and individual differences in visual concept learning as measured by functional MRI
TLDR
Dynamic changes in brain regions active while learning novel visual concepts were examined in humans using functional magnetic resonance imaging, finding a progression from initial right-hemisphere processing of specific instances to bilateral activity as left-hemispheric conceptual processes are recruited may underlie the development of many forms of visual knowledge.
Hemispheric asymmetry in the induction of false memories
  • Y. Ito
  • Psychology, Medicine
    Laterality
  • 2001
TLDR
The results of the present study suggest that the model of RH coarse semantic coding and LH fine semantic coding is applicable not only to language processing but also to verbal memory.
Left and right memory revisited: Electrophysiological investigations of hemispheric asymmetries at retrieval
TLDR
Differences between the data pattern observed in the present study with lateralized retrieval and that in a prior study withateralized encoding support the notion that hemispheric processing is highly integrated in the intact brain, and highlight the need to treat lateralization at different stages as distinct.
Visuospatial processing and the right-hemisphere interpreter
TLDR
Evidence is presented in favor of the view that the right hemisphere can be considered more "visually intelligent" than the left, and the existence of a "right-hemisphere interpreter" dedicated to constructing a representation of the visual world is postulated.
How do our brain hemispheres cooperate to avoid false memories?
TLDR
The data suggest that interhemispheric cooperation does not improve the ability to tell old and new apart, but rather evokes a conservative response tendency.
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 46 REFERENCES
Lexical judgements after right- or left-hemisphere injury
TLDR
Patients with unilateral left- or right-hemisphere lesions were asked to make similarity judgments to visually presented words on the basis of rhyme, meaning or visual similarity, and the results are generally consistent with normal and split-brain lateralization findings.
Hemispheric differences in mnemonic processing: The effects of left hemisphere interpretation
TLDR
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 theleft hemisphere superiority in interpretation and inference effect memory performance.
Dissociation of language and cognition. A psychological profile of two disconnected right hemispheres.
TLDR
The results suggest that the presence of language in the right hemisphere, a brain system that ordinarily does not possess such competence, need not necessarily confer the full complement of cognitive skills associated with the language processing skills of the left hemisphere.
Variability in right hemisphere language function after callosal section: evidence for a continuum of generative capacity
TLDR
The right hemisphere language systems in both patients were shown to be capable of semantic information processing, but they differed in their abilities to process phonetic information, follow verbal commands, and produce linguistic responses.
Profiles of right hemisphere language and speech following brain bisection
TLDR
Preliminary results suggest that the case displaying greater semantic power also possessed some syntactic competence, and this same case (V.P.) was also capable of expressive language from the right hemisphere.
Contributions of stimulus encoding and memory search to right hemisphere superiority in face recognition: Behavioural and electrophysiological evidence
TLDR
Equal efficiency of the hemispheres in stimulus encoding, but RH superiority in memory search is suggested, with a long-lasting ERP negativity contralateral to the stimulated hemifield.
Form-specific visual priming in the right cerebral hemisphere.
TLDR
Results of 4 experiments indicate that both within-modality and case-specific visual priming for words are greater when test stimuli are presented initially to the right cerebral hemisphere (RH), and suggest that at least 2 separate systems encode the visual representations that produce priming.
Independent Attentional Scanning in the Separated Hemispheres of Split-Brain Patients
TLDR
In a group of four commis-surotomy patients, the search rates for bilateral stimulus arrays was found to be approximately twice as fast as the search rate for unilateral arrays, indicating that the separated hemispheres were able to scan their respective hemifields independently.
Processing of semantic anomaly by right and left hemispheres of commissurotomy patients. Evidence from event-related brain potentials.
TLDR
The ability of 5 commissurotomized patients to appreciate semantic anomalies presented to their right and left hemispheres was tested using both electrophysiological and behavioural measures, suggesting possible relationships within language generation and semantic priming.
Cerebral hemispheric mechanisms in the retrieval of ambiguous word meanings
TLDR
The present results suggest that, while automatic processing occurs in both hemispheres, only the left hemisphere engages in controlled processing of ambiguous word meanings and that the right hemisphere lexicon possesses a richer endowment than earlier thought.
...
1
2
3
4
5
...