We propose to use lesion studies to determine whether there is similar processing of color and form information in human and macaque visual cortex. Studies with macaque monkeys will continue to explore the contribution of individual cortical visual areas, with the goal of determining capabilities that are uniquely reflective of each area's activity. We have found that localized lesions in near-extrastriate visual areas V2 and V4, cause precisely retintopic losses of complex, but not fundamental, visual functions. These studies will be extended to the effects of lesions of inferotemporal visual areas TEO and TE, which receive much of their input from the above cortical areas. We will use the cumulated information we have obtained about extrastriate macaque visual areas to explore parallel organization in the human visual system. Particular attention will be paid to lesions of near extrastriate visual areas, since the visual distribution of losses can help explore parallels between human and macaque visual cortex. Our studies will focus on human cerebral achromatopsia and visual form agnosias, which are among the most dramatic disorders suggesting that human visual cortex is organized into functional modules.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY008898-08
Application #
2711036
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1991-08-01
Project End
2001-07-31
Budget Start
1998-08-01
Budget End
1999-07-31
Support Year
8
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Rochester
Department
Ophthalmology
Type
Schools of Dentistry
DUNS #
208469486
City
Rochester
State
NY
Country
United States
Zip Code
14627
Hayes, Randall D; Merigan, William H (2007) Mechanisms of Sensitivity Loss due to Visual Cortex Lesions in Humans and Macaques. Cereb Cortex 17:1117-28
Huxlin, K R; Saunders, R C; Marchionini, D et al. (2000) Perceptual deficits after lesions of inferotemporal cortex in macaques. Cereb Cortex 10:671-83
Merigan, W H (2000) Cortical area V4 is critical for certain texture discriminations, but this effect is not dependent on attention. Vis Neurosci 17:949-58
Huxlin, K R; Merigan, W H (1998) Deficits in complex visual perception following unilateral temporal lobectomy. J Cogn Neurosci 10:395-407
Merigan, W H; Pham, H A (1998) V4 lesions in macaques affect both single- and multiple-viewpoint shape discriminations. Vis Neurosci 15:359-67
Merigan, W; Freeman, A; Meyers, S P (1997) Parallel processing streams in human visual cortex. Neuroreport 8:3985-91
Merigan, W H (1996) Basic visual capacities and shape discrimination after lesions of extrastriate area V4 in macaques. Vis Neurosci 13:51-60
Merigan, W H; Maunsell, J H (1993) How parallel are the primate visual pathways? Annu Rev Neurosci 16:369-402