Hemispheric Asymmetry in Categorical Versus Coordinate Visuospatial Processing Revealed by Temporary Cortical Deactivation

Kosslyn (1987) proposed that the left hemisphere is better than the right hemisphere at categorical visuospatial processing while the right hemisphere is better than the left hemisphere at coordinate visuospatial processing. In 134 patients, one hemisphere (and then usually the other) was temporarily deactivated by intracarotid injection of sodium amobarbital. After a hemisphere was deactivated, a cognitive test battery was conducted, which included categorical and coordinate visuospatial tasks. Using this technique, the processing capabilities of the intact hemisphere could be determined, thus directly testing Kosslyn's hypothesis regarding hemispheric specialization. Specifically, if the left hemisphere does preferentially process categorical visuospatial relationships, then its deactivation should result in more errors during categorical tasks than right hemisphere deactivation and vise versa for the right hemisphere regarding coordinate tasks. The pattern of results obtained in both categorical and coordinate tasks was consistent with Kosslyn's hypothesis when task difficulty was sufficiently high. However, when task difficulty was low, a left hemispheric processing advantage was found for both types of tasks indicating that: (1) the left hemisphere may be better at easy tasks regardless of the type of task and (2) the proposed hemispheric processing asymmetry may only become apparent during sufficiently demanding task conditions. These results may explain why some investigators have failed to find a significant hemispheric processing asymmetry in visuospatial categorical and coordinate tasks.

[1]  H. Egeth,et al.  Differential specialization of the cerebral hemispheres for the perception of sameness and difference , 1972 .

[2]  Leslie G. Ungerleider.  Two cortical visual systems , 1982 .

[3]  F. Newcombe,et al.  Disorders of space exploration and cognition E. De Renzi. John Wiley, Chichester (1982). 268 pp. , 1982, Neuroscience.

[4]  S. Kosslyn.  Seeing and imagining in the cerebral hemispheres: a computational approach. , 1987, Psychological review.

[5]  C. B. Cave,et al.  Evidence for two types of spatial representations: hemispheric specialization for categorical and coordinate relations. , 1989, Journal of experimental psychology. Human perception and performance.

[6]  G. Keppel.  Data analysis for research designs , 1990 .

[7]  J. Hellige,et al.  Categorization versus distance: Hemispheric differences for processing spatial information , 1989, Memory & cognition.

[8]  S. Kosslyn,et al.  The development of spatial relation representations: evidence from studies of cerebral lateralization. , 1990, Journal of experimental child psychology.

[9]  P. Servos,et al.  A clear left hemisphere advantage for visuo-spatially based verbal categorization , 1990, Neuropsychologia.

[10]  J. Sergent.  Judgments of relative position and distance on representations of spatial relations. , 1991, Journal of experimental psychology. Human perception and performance.

[11]  M. Corballis.  Left Brain, Right Brain , 1991, Science.

[12]  R P Lesser,et al.  Dominant-side intracarotid amobarbital spares comprehension of word meaning. , 1991, Archives of neurology.

[13]  D. J. Felleman,et al.  Distributed hierarchical processing in the primate cerebral cortex. , 1991, Cerebral cortex.

[14]  S. Kosslyn,et al.  Categorical versus coordinate spatial relations: computational analyses and computer simulations. , 1992, Journal of experimental psychology. Human perception and performance.

[15]  William J. Hoyer,et al.  Hemispheric specialization for categorical and coordinate spatial representations: A reappraisal , 1992, Memory & cognition.

[16]  P. Goldman-Rakic,et al.  Dissociation of object and spatial processing domains in primate prefrontal cortex. , 1993, Science.

[17]  B. Laeng.  Lateralization of Categorical and Coordinate Spatial Functions: A Study of Unilateral Stroke Patients , 1994, Journal of Cognitive Neuroscience.

[18]  Individual variation in hemispheric asymmetry: multitask study of effects related to handedness and sex. , 1994, Journal of experimental psychology. General.

[19]  J. Hellige,et al.  Categorical versus Coordinate Spatial Processing: Effects of Blurring and Hemispheric Asymmetry , 1994, Journal of Cognitive Neuroscience.

[20]  Bruno Laeng,et al.  Cerebral lateralization for the processing of spatial coordinates and categories in left- and right-handers , 1995, Neuropsychologia.

[21]  G. Winocur,et al.  Dissociation of pathways for object and spatial vision: a PET study in humans , 1995, Neuroreport.

[22]  Leslie G. Ungerleider,et al.  Object and spatial visual working memory activate separate neural systems in human cortex. , 1996, Cerebral cortex.

[23]  R. Bruyer,et al.  Dissociation between Categorical and Coordinate Spatial Computations: Modulation by Cerebral Hemispheres, Task Properties, Mode of Response, and Age , 1997, Brain and Cognition.

[24]  C. Michimata.  Hemispheric Processing of Categorical and Coordinate Spatial Relations in Vision and Visual Imagery , 1997, Brain and Cognition.

[25]  S. Kosslyn,et al.  Neural systems that encode categorical versus coordinate spatial relations: PET investigations , 1998, Psychobiology.

[26]  S. Christman,et al.  Upper and lower visual field differences in categorical and coordinate judgments , 1998 .

[27]  Kara D. Federmeier,et al.  Categorical and Metric Spatial Processes Distinguished by Task Demands and Practice , 1999, Journal of Cognitive Neuroscience.

[28]  Stephen M. Kosslyn,et al.  Encoding Categorical and Coordinate Spatial Relations Without Input-Output Correlations: New Simulation Models , 1999, Cogn. Sci..