The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform

Michael S. Gazzaniga - One of the best experts on this subject based on the ideXlab platform.

  • Right Hemisphere Dominance in Visual Statistical Learning
    Journal of Cognitive Neuroscience, 2011
    Co-Authors: Matthew E. Roser, József Fiser, Richard N. Aslin, Michael S. Gazzaniga
    Abstract:

    Several studies report a Right Hemisphere advantage for visuospatial integration and a left Hemisphere advantage for inferring conceptual knowledge from patterns of covariation. The present study examined hemispheric asymmetry in the implicit learning of new visual feature combinations. A split-brain patient and normal control participants viewed multishape scenes presented in either the Right or the left visual fields. Unbeknownst to the participants, the scenes were composed from a random combination of fixed pairs of shapes. Subsequent testing found that control participants could discriminate fixed-pair shapes from randomly combined shapes when presented in either visual field. The split-brain patient performed at chance except when both the practice and the test displays were presented in the left visual field (Right Hemisphere). These results suggest that the statistical learning of new visual features is dominated by visuospatial processing in the Right Hemisphere and provide a prediction about how fMRI activation patterns might change during unsupervised statistical learning.

  • Language and speech capacity of the Right Hemisphere
    Neuropsychologia, 2002
    Co-Authors: Michael S. Gazzaniga, Steven A. Hillyard
    Abstract:

    Abstract Right Hemisphere language and speech capacity was further analyzed in brain-bisected patients. The results indicate that little or no syntactic capability exists in the Right Hemisphere. The only semantic dimension that was comprehended in a series of pictorial-verbal matching tests was the affirmative-negative. Moreover, earlier indications of a Right Hemisphere speech capacity could not be confirmed. Differences in verbal reaction time to visual stimuli projected to Right and left Hemispheres were alternatively interpreted as consequences of subcortical transfer mechanisms or cross-cuing strategies.

  • Reading with a limited lexicon in the Right Hemisphere of a callosotomy patient.
    Neuropsychologia, 1992
    Co-Authors: Kathleen Baynes, Mark Jude Tramo, Michael S. Gazzaniga
    Abstract:

    Abstract The generality of the observation that there is a lexicon present in the Right Hemisphere of callosotomy patients has been the subject of some dispute. In the series operated on at Dartmouth Hitchcock Medical Center, only two patients have been shown to have a Right Hemisphere lexicon. This paper reports the existence of a visual and an auditory lexicon in a new patient D.R. and discusses its significance in understanding the role of the Right Hemisphere in normal and dysfunctional language.

Tara Eberhardt Mckee - One of the best experts on this subject based on the ideXlab platform.

  • unilateral spatial neglect relation to rehabilitation outcomes in patients with Right Hemisphere stroke
    Archives of Physical Medicine and Rehabilitation, 2005
    Co-Authors: Robert Gillen, Howard Tennen, Tara Eberhardt Mckee
    Abstract:

    Abstract Gillen R, Tennen H, McKee T. Unilateral spatial neglect: relation to rehabilitation outcomes in patients with Right Hemisphere stroke. Arch Phys Med Rehabil 2005;86: 763–7. Objective To examine the relation between left unilateral spatial neglect (USN) and rehabilitation outcomes in patients with Right Hemisphere stroke. Design A retrospective analysis of a database of Right Hemisphere stroke patients. Setting Acute inpatient rehabilitation hospital. Participants Patients (N=175) with a diagnosis of Right Hemisphere stroke who had undergone a neuropsychologic screening including assessment of USN and depressive symptoms at time of admission to an inpatient rehabilitation program. Interventions Not applicable. Main outcome measures Functional status was evaluated with the FIM instrument at admission and discharge. The relationship between USN, depressive symptoms, cognitive functioning, length of stay (LOS), and rate of progress in rehabilitation was examined via univariate (correlational) and multivariate (Cox regression) analyses. Results Patients with USN had longer LOS and progressed more slowly compared with those without USN. When matched against patients with equally poor functional status at admission, USN patients still had longer admissions and progressed more slowly. Conclusions USN is a unique predictor of rehabilitation outcomes in patients with Right Hemisphere stroke. Identification of those specific functional skill areas most affected by USN may make possible the development of targeted interventions aimed at these key areas.

Alvaro Pascualleone - One of the best experts on this subject based on the ideXlab platform.

  • self recognition and the Right Hemisphere
    Nature, 2001
    Co-Authors: Julian Paul Keenan, Aaron Nelson, Margaret Oconnor, Alvaro Pascualleone
    Abstract:

    Although monkeys can perceive complex stimuli such as faces1, only the higher apes are capable of recognizing their own face in a mirror2. Here we show that in humans the Right Hemisphere of the brain seems to be preferentially involved in self-face recognition. Our findings indicate that neural substrates of the Right Hemisphere may selectively participate in processes linked to self-awareness.

Paul M Corballis - One of the best experts on this subject based on the ideXlab platform.

  • visuospatial processing and the Right Hemisphere interpreter
    Brain and Cognition, 2003
    Co-Authors: Paul M Corballis
    Abstract:

    Popular views of hemispheric asymmetry hold that the left Hemisphere is specialized for linguistic and cognitive processes and fine motor control, whereas the Right is specialized for visuospatial processing. Although this dichotomy contains more than a grain of truth, it is an oversimplification. Experiments with split-brain patients have demonstrated that the left Hemisphere retains relatively sophisticated visuospatial abilities, and that the asymmetries that favor the Right Hemisphere are subtler than those that favor the left. A consideration of the constructive nature of visual perception, and the organization of the visual system in the two Hemispheres suggests that asymmetries are likely to arise relatively late in visual processing in areas that represent both sides of visual space. I present evidence in favor of the view that the Right Hemisphere can be considered more ‘‘visually intelligent’’ than the left, and postulate the existence of a ‘‘Right-Hemisphere interpreter’’ dedicated to constructing a representation of the visual world.

  • Visual grouping and the Right-Hemisphere interpreter
    International Congress Series, 2003
    Co-Authors: Paul M Corballis
    Abstract:

    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 have been found in tasks tapping relatively high-level cognitive functions such as language, syllogistic reasoning, and schema-based cognition, all of which are performed much better by the left Hemisphere in most patients. These findings have led Gazzaniga and his colleagues to postulate the existence of a left-lateralized cognitive module called the “interpreter” that performs these functions and attempts to resolve ambiguous events as it occurs in the world. Characterization of Right-Hemisphere specialization has been more problematic. Some visuospatial functions seem to be performed equivalently by both Hemispheres, whereas others appear to be strongly Right lateralized. I describe a series of behavioral experiments with split-brain patients that suggest that the two Hemispheres process visual information in qualitatively different ways. Specifically, it appears that the left Hemisphere does not have access to all of the visual mechanisms that are available to the Right Hemisphere. These data suggest that the Right Hemisphere also performs “interpretive” functions that are geared towards resolving the spatial ambiguity that is inherent in visual perception.

Marilee Monnot - One of the best experts on this subject based on the ideXlab platform.

  • neurology of affective prosody and its functional anatomic organization in Right Hemisphere
    Brain and Language, 2008
    Co-Authors: Elliott D Ross, Marilee Monnot
    Abstract:

    Abstract Unlike the aphasic syndromes, the organization of affective prosody in brain has remained controversial because affective-prosodic deficits may occur after left or Right brain damage. However, different patterns of deficits are observed following left and Right brain damage that suggest affective prosody is a dominant and lateralized function of the Right Hemisphere. Using the Aprosodia Battery, which was developed to differentiate left and Right Hemisphere patterns of affective-prosodic deficits, functional–anatomic evidence is presented in patients with focal ischemic strokes to support the concepts that (1) affective prosody is a dominant and lateralized function of the Right Hemisphere, (2) the intrahemispheric organization of affective prosody in the Right Hemisphere, with the partial exception of Repetition, is analogous to the organization of propositional language in the left Hemisphere and (3) the aprosodic syndromes are cortically based as part of evolutionary adaptations underlying human language and communication.