One of the most important problems in understanding how the brain can analyze space is how it can construct an accurate representation of the world around it from the shifting images generated by a moving eye. Patients with parietal lesions have difficulty with accurately perceiving the space around them and generating spatially accurate behavior, especially when their eyes move. A particular part of the parietal cortex, the lateral intraparietal area (LIP) is thought to be important in the mechanisms underlying spatial localization. Studies in LIP of the monkey have revealed a phenomenon, the process of perisaccadic receptive field shifts, by which the brain could possibly solve the problem of how to achieve spatially accurate behavior despite a moving eye. Most visually responsive neurons in the brain are defined by their receptive fields, the area of the retina from which visual stimuli evoke neural activity. In LIP, visual receptive fields are not fixed to the retina, nor do they statically or explicitly describe an area of space in supraretinal coordinates. Instead, preliminary work has demonstrated that receptive fields are dynamic: around the time of a saccade they shift on the retina. LIP neurons respond to stimuli briefly flashed outside their classic receptive fields when a saccade brings the spatial location of the vanished stimuli into their receptive fields. By freeing vector processing from retinal constraints, receptive field shifts provide a mechanism by which the brain could achieve spatially accurate visual analysis. This proposal seeks to understand the phenomenology and underlying mechanisms of receptive field shifts in LIP of the awake, behaving monkey, in order to understand the mechanisms that could underlie accurate spatial perception and action. It has 4 specific aims: (1) to quantify the phenomenon of receptive field shifts, (2) to analyze the long-term aspects of accurate spatial memory in the parietal cortex; (3) to determine the metric of space used by the parietal cortex; and (4) to use intracortical application of GABA agonists and antagonists to test specific models of how the phenomenon of shifting receptive fields might be accomplished by the parietal cortex. By elucidating the metrics of the spatial representation in LIP, the topology of perisaccadic receptive field shifts in LIP, the demonstration of a long-term, intertrial memory in parietal cortex, and testing current models of the genesis of receptive field shifts, these experiments should enable a better, more coherent understanding of how the parietal cortex represents visual space. This should, in turn, enable us to understand why patients with parietal deficits behave as they do, and how to design possible strategies for their rehabilitation and treatment.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY014978-04
Application #
7105555
Study Section
Visual Sciences B Study Section (VISB)
Program Officer
Oberdorfer, Michael
Project Start
2003-08-01
Project End
2008-07-31
Budget Start
2006-08-01
Budget End
2007-07-31
Support Year
4
Fiscal Year
2006
Total Cost
$371,734
Indirect Cost
Name
New York State Psychiatric Institute
Department
Type
DUNS #
167204994
City
New York
State
NY
Country
United States
Zip Code
10032
Semework, Mulugeta; Steenrod, Sara C; Goldberg, Michael E (2018) A spatial memory signal shows that the parietal cortex has access to a craniotopic representation of space. Elife 7:
Wang, Xiaodong; Guo, Xiaotao; Chen, Lin et al. (2017) Auditory to Visual Cross-Modal Adaptation for Emotion: Psychophysical and Neural Correlates. Cereb Cortex 27:1337-1346
Zhang, Wujie; Falkner, Annegret L; Krishna, B Suresh et al. (2017) Coupling between One-Dimensional Networks Reconciles Conflicting Dynamics in LIP and Reveals Its Recurrent Circuitry. Neuron 93:221-234
Sun, Linus D; Goldberg, Michael E (2016) Corollary Discharge and Oculomotor Proprioception: Cortical Mechanisms for Spatially Accurate Vision. Annu Rev Vis Sci 2:61-84
Wang, Xiaolan; Fung, C C Alan; Guan, Shaobo et al. (2016) Perisaccadic Receptive Field Expansion in the Lateral Intraparietal Area. Neuron 90:400-9
Semework, Mulugeta (2015) Microstimulation: Principles, Techniques, and Approaches to Somatosensory Neuroprosthesis. Crit Rev Biomed Eng 43:61-95
Semework, Mulugeta (2015) A Customizable Multimodality Imaging Compound That Relates External Landmarks to Internal Structures. J Nucl Med Technol 43:267-74
Krishna, B Suresh; Ipata, Anna E; Bisley, James W et al. (2014) Extrafoveal preview benefit during free-viewing visual search in the monkey. J Vis 14:
Zhang, Mingsha; Wang, Xiaolan; Goldberg, Michael E (2014) A spatially nonselective baseline signal in parietal cortex reflects the probability of a monkey's success on the current trial. Proc Natl Acad Sci U S A 111:8967-72
Steenrod, Sara C; Phillips, Matthew H; Goldberg, Michael E (2013) The lateral intraparietal area codes the location of saccade targets and not the dimension of the saccades that will be made to acquire them. J Neurophysiol 109:2596-605

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