FUNCTIONAL STREAMS IN THE PRIMATE VISUAL CORTEX

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Mount Sinai School Of Medicine Of Nyu Of New York University New York, Ny 100296574

Grant 5R01EY011276-05 from National Eye Institute, IRG: ZRG1

Abstract: The Principal Investigator and his team propose to expand our understanding of the functions of the magnocellular and parvocellular streams in primate vision and especially their relationships to the anatomically identified neural populations of the cytochrome oxidase blobs and stripes in areas V1 and V2. This will be achieved by recording neural activity from the visual cortex of macaque monkeys using optical methods and analyzing the images with extensions of the Karhunen-Loeve (KL) principle component methods. This approach will provide information about both the spatial and temporal distributions of coordinated activity. They suggest that this information is contained in a small number of spatially segregated dynamical components and that some of these components correspond to known cortical structures such as ocular dominance columns. The study will 1) investigate the contributions of known neuronal subpopulations (streams) to the optically monitored neuronal activity by using two complimentary methods a) use of visual stimuli that excite primarily one cell populations such as the M-stream and b) silence selected neuronal populations by pressure injections of Mg++ or lidocaine into portions of the lateral geniculate nucleus, 2) compare optical signals recorded from CO blobs with those recorded from interblob regions, 3) compare the optical activity maps with the distribution of CO blobs, and 4) correlate the optical activity with simultaneously recorded electrical activity of cortical neurons. The PI believes that these combined apparoches will reveal further organizational principles of the visual cortex and will deepen our understanding of the functions of its constituent streams.

Keywords: cytochrome oxidase, enzyme activity, protein structure /function, visual cortex, afferent nerve, lateral geniculate body, neural transmission, neuron, visual stimulus, Macaca, computer network, computer processing of laboratory data, dye, electrophysiology, image processing, imaging /visualization, mathematical model

Project start date: 1996-08-01

Project end date: 2002-07-31

5R01EY011276-05 (2000): $440842

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FUNCTIONAL STREAMS IN THE PRIMATE VISUAL CORTEX

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Mount Sinai School Of Medicine Of Nyu Of New York University New York, Ny 100296574

Grant 5R01EY011276-04 from National Eye Institute, IRG: ZRG1

Abstract: The Principal Investigator and his team propose to expand our understanding of the functions of the magnocellular and parvocellular streams in primate vision and especially their relationships to the anatomically identified neural populations of the cytochrome oxidase blobs and stripes in areas V1 and V2. This will be achieved by recording neural activity from the visual cortex of macaque monkeys using optical methods and analyzing the images with extensions of the Karhunen-Loeve (KL) principle component methods. This approach will provide information about both the spatial and temporal distributions of coordinated activity. They suggest that this information is contained in a small number of spatially segregated dynamical components and that some of these components correspond to known cortical structures such as ocular dominance columns. The study will 1) investigate the contributions of known neuronal subpopulations (streams) to the optically monitored neuronal activity by using two complimentary methods a) use of visual stimuli that excite primarily one cell populations such as the M-stream and b) silence selected neuronal populations by pressure injections of Mg++ or lidocaine into portions of the lateral geniculate nucleus, 2) compare optical signals recorded from CO blobs with those recorded from interblob regions, 3) compare the optical activity maps with the distribution of CO blobs, and 4) correlate the optical activity with simultaneously recorded electrical activity of cortical neurons. The PI believes that these combined apparoches will reveal further organizational principles of the visual cortex and will deepen our understanding of the functions of its constituent streams.

Keywords: cytochrome oxidase, enzyme activity, protein structure /function, visual cortex, afferent nerve, lateral geniculate body, neural transmission, neuron, visual stimulus, Macaca, computer network, computer processing of laboratory data, dye, electrophysiology, image processing, imaging /visualization, mathematical model

Project start date: 1996-08-01

Project end date: 2001-07-31

5R01EY011276-04 (1999): $432749

5R01EY011276-03 (1998): $424736

5R01EY011276-02 (1997): $426060

INFORMATION TRANSFER AND CONTRAST SENSITIVITY

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Rockefeller University New York, Ny 100656399

Grant 5R01EY004888-05 from National Eye Institute, IRG: VISB

Abstract: This proposal aims at a better understanding of the functional organization of the central visual pathways of mammals, and attempts to relate visual functions to neuronal populations in the primate. I will focus on two main problems 1) What are the dynamic properties of the contrast gain control we recently discovered in the Lateral Geniculate Nucleus (LGN)? and 2) What is the neural substrate for the psychophysically determined luminance and color contrast sensitivities? The first question stems from the observations that the LGN is a dynamic filter of the incoming retinal information, and that its filtering (attenuation) of retinal input increases with stimulus contrast. This observation lead to a set of new experiments, in which the contrast of a pattern is modulated in time. I will record in anesthized and paralyzed cats and monkeys the responses of single LGN cells together with their retinal input (recorded as synaptic (S) potentials), and measure the time course with which the LGN adjusts its transmission ratio (LGN response/retinal response) following a step increase in contrast. The importance of temporal and spatial stimulus parameters, as well as that of retinal eccentricity and binocular interactions, will all be explored. The second question is stimulated by the observation that in the monkey LGN the parvocellular neuons (and their drives, the P cells) are much less sensitive to luminance contrast than the magnocellular neurons (or the retinal M cells), and by recent psychophysical work (Mullen, 1985) which compared the contrast sensitivity for color and luminance patterns in humans. I will establish which neuronal population could account for these results by measruing the responses of single P and M cells in the monkey LGN to both luminance and chromatic patterns. I will also measure the sensitivities of the receptor field center and periphery to luminance and color modulations, to uncover the reason for the unbounded increase in response to color stimuli with stimulus size, noted in the P cells, and the source of the difference in contrast gain between M and P cells. The results will shed light on the function of the M cells and P cells in primate vision.

Keywords: BRAIN, DIENCEPHALON, THALAMUS, GENICULATE BODY LATERAL, BRAIN, NEURAL PATHWAYS AND TRACTS, CORTICOFUGAL SYSTEMS, CELL TYPES, EYE, RETINA, EYE, VISION, COLOR VISION, EYE, VISION, PHOTOSENSITIVITY, EYE, VISUAL FEEDBACK, EYE, VISUAL PERCEPTION, INFORMATION PROCESSING AND CONTROL (NEURAL), OPTICS, LIGHT EMISSION, LUMINESCENCE, SENSORY-PERCEPTUAL PROCESSES, SEQUENTIAL PERCEPTION, psychophysics, CELLS, SINGLE CELL ANALYSIS, EYE, RETINA, RETINAL GANGLION, EYE, VISION, BINOCULAR FUSION, EYE, VISUAL STIMULUS, NERVOUS SYSTEM, NEURONS, INTERNEURONS, NEUROPHYSIOLOGY, NEURAL TRANSMISSION, STIMULUS-RESPONSE, ANIMALS, CHORDATES, MAMMALS, CARNIVORES, CATS, ANIMALS, CHORDATES, MAMMALS, PRIMATES, OLD WORLD MONKEYS, MACACA SP., BIOMEDICAL SYSTEMS AUTOMATED, COMPUTER PROCESSING OF LABORATORY DATA, electrophysiology

Project start date: 1984-09-01

Project end date: 1992-03-31

NEURONAL ACTIVITY AND OPTICAL SIGNALS IN THE BRAIN

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Ophthalmologymount Sinai School Of Medicine Of Nyu
of New York University
new York, Ny 100296574

Grant 5R01EY012867-02 from National Eye Institute, IRG: ZRG1

Abstract: The purpose of the proposed research is to determine the quantitative relationship between neural activity in the cortex and intrinsic optical signals (signals that do not require the application of dyes). Optical imaging of the cortex, especially of intrinsic optical signals, has been used extensively in the past decade to explore the functional organization in the brain, especially in the visual cortex. Some of the reported results have been surprising and some remain controversial. Despite the natural appeal of the technique and the wide attention that its results have attracted, very little is known in quantitative detail about the coupling between the neural activity and the intrinsic optical signal, which has several components. Such knowledge is crucial for the proper interpretation of the activity and selectivity selectivity maps obtained with optical imaging. An investigation of the following questions is proposed 1) What is the quantitative relationship between the neural activity and the optical signal? 2) Is the neural-optical relationship uniform across the cortex (isotropic)? 3) What aspects of neural activity (spikes, synaptic activity) are represented by the optical signal? 4) What is the contribution to the optical signal of the various functional or anatomical cell types in the cortex? The results of these studies will allow a quantitative interpretation of activity maps obtained not only by optical imaging, but also by other important imaging technologies that rely on the hemodynamic filter, such as fMRI and PET, which are now used not only in research but also as diagnostic tools in clinical practice

Keywords: biological signal transduction, brain electrical activity, neural information processing, neuron, visual cortex cell type, neurophysiology, synapse, visual stimulus brain mapping, cat, computer data analysis, computer processing of laboratory data, electrode, electrophysiology, functional magnetic resonance imaging, positron emission tomography

Project start date: 2000-03-08

Project end date: 2004-02-29

5R01EY012867-02 (2001): $228176

1R01EY012867-01 (2000): $270586

FUNCTIONAL ORGANIZATION OF THE RETINA AND LGN

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Rockefeller University New York, Ny 100656399

Grant 5R01EY004888-09 from National Eye Institute, IRG: ZRG1

Abstract: The long-term aim of my research is to understand the neural underpinning of visual perception in man. Although it is well established that the primate visual system employs two distinct visual streams, the parvocellular-projecting (P) and the magnocellular-projecting (M) streams, their respective roles in vision are still controversial, largely because recent research has raised fundamental questions regarding the organization of the receptive fields of neurons in these streams. The thorniest of these questions include the linearity of center/surround interactions in P cells  receptive fields, and the nature of the photoreceptors  input (both cones and rods) to the center and surround of P and M receptive fields. In addition, our understanding of the retinal mechanisms which account for the different properties of the cells in the M and P streams is partial at best. The studies proposed here will address these issues by investigating, in quantitative detail, the functional organization of receptive fields of visual neurons in the primate retina and Lateral Geniculate Nucleus (LGN), using macaque monkeys whose visual system is very similar to that of humans. Retinal ganglion cell activity will be monitored extracellularly as synaptic (S) potentials recorded together with LGN responses in the LGNs of anesthetized, paralyzed monkeys. Visual stimuli designed to excite one or more classes of cones in the center or surround regions of the receptive field will be temporally modulated by an  m-sequence  of pulses or by a sum-of-sinusoids, to extract information about both linear and nonlinear aspects of the response dynamics. The proposed study will a) investigate the temporal, spatial and chromatic properties of the recently-discovered nonlinear (divisive) surround region of the receptive fields of P cells, b) determine if the surround mechanism of P cells has both linear and nonlinear components, c) determine whether the cone input to the surrounds of P receptive fields is characteristically pure or mixed, d) determine the degree to which rods contribute to the response of P and M cells, and e) compare the processing of color information in retinal ganglion cells with that of their LGN targets. These studies will resolve current controversies, and provide new insights into the roles that the M and P streams play in vision and into the cellular mechanisms which determine their responses and capacities. Such insights will be important for the understanding of both normal and pathological aspects of human vision.

Keywords: lateral geniculate body, neural information processing, retina, visual perception, visual photoreceptor, color vision, cone cell, dark adaptation, light adaptation, neuron, psychophysics, rod cell, synapse, visual stimulus, Macaca, data collection

Project start date: 1984-09-01

Project end date: 1996-11-30

5R01EY004888-09 (1994): $308217

FUNCTIONAL ORGANIZATION OF RETINA AND LGN

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Rockefeller University
new York, Ny 100656399

Grant 2R01EY004888-08A1 from National Eye Institute, IRG: ZRG1

Abstract: The long-term aim of my research is to understand the neural underpinning of visual perception in man. Although it is well established that the primate visual system employs two distinct visual streams, the parvocellular-projecting (P) and the magnocellular-projecting (M) streams, their respective roles in vision are still controversial, largely because recent research has raised fundamental questions regarding the organization of the receptive fields of neurons in these streams. The thorniest of these questions include the linearity of center/surround interactions in P cells´ receptive fields, and the nature of the photoreceptors´ input (both cones and rods) to the center and surround of P and M receptive fields. In addition, our understanding of the retinal mechanisms which account for the different properties of the cells in the M and P streams is partial at best. The studies proposed here will address these issues by investigating, in quantitative detail, the functional organization of receptive fields of visual neurons in the primate retina and Lateral Geniculate Nucleus (LGN), using macaque monkeys whose visual system is very similar to that of humans. Retinal ganglion cell activity will be monitored extracellularly as synaptic (S) potentials recorded together with LGN responses in the LGNs of anesthetized, paralyzed monkeys. Visual stimuli designed to excite one or more classes of cones in the center or surround regions of the receptive field will be temporally modulated by an ´m-sequence´ of pulses or by a sum-of-sinusoids, to extract information about both linear and nonlinear aspects of the response dynamics. The proposed study will a) investigate the temporal, spatial and chromatic properties of the recently-discovered nonlinear (divisive) surround region of the receptive fields of P cells, b) determine if the surround mechanism of P cells has both linear and nonlinear components, c) determine whether the cone input to the surrounds of P receptive fields is characteristically pure or mixed, d) determine the degree to which rods contribute to the response of P and M cells, and e) compare the processing of color information in retinal ganglion cells with that of their LGN targets. These studies will resolve current controversies, and provide new insights into the roles that the M and P streams play in vision and into the cellular mechanisms which determine their responses and capacities. Such insights will be important for the understanding of both normal and pathological aspects of human vision

Keywords: lateral geniculate body, neural information processing, retina, visual perception, visual photoreceptor color vision, cone cell, dark adaptation, light adaptation, neuron, psychophysics, rod cell, synapse, visual stimulus Macaca, data collection

Project start date: 1984-09-01

Project end date: 1996-11-30

2R01EY004888-08A1 (1993): $285429

Effects Of V1 Feedback On LGN Function

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Mount Sinai School Of Medicine Of Nyu Of New York University New York, Ny 100296574

Grant 5R01EY016371-04 from National Eye Institute, IRG: CVP

Abstract: The long range goal of our research is to understand how thalamic neurons integrate their various feedforward and feedback inputs, and what role these inputs play in the flow of information from retina to cortex through the thalamus. Most of the inputs and synapses in the mammalian lateral geniculate nucleus (LGN) are extraretinal, but the way in which these diverse inputs are integrated to control the flow of visual information from retina to cortex is not understood. In particular, the influence of the descending inputs from the cortex and the perigeniculate nucleus (PGN) on the spatio-temporal properties of receptive fields of LGN relay neurons is unknown. To address this gap in our knowledge, we shall study the temporal and spatial aspects of receptive fields in monkey LGN before and during inactivation of the cortical feedback to the LGN. The dynamical properties will be probed with a double m-sequence stimulation paradigm, which will provide new information about both the linear and non-linear dynamics of these neurons, and will expose the effects that the feedback from V1 has on this dynamical behavior. Our hypothesis is that the corticofugal feedback to the LGN has a significant effect on four specific aspects of LGN function dynamics, receptive field organization, transmission from retina to cortex and response gain. The proposed studies will furnish new information about the effects of the corticofugal pathway on several important dynamical and spatial parameters of the receptive fields of LGN relay cells. These findings will extend and deepen our understanding of the function of this massive yet elusive neural pathway, and pave the way for realistic modeling of the early stages of the visual system. Because such descending pathways are ubiquitous in the brain, the findings are likely to relevant to other reciprocally connected brain regions.

Keywords: lateral geniculate body, neural information processing, visual feedback, retina, visual cortex, visual pathway, visual phototransduction, Macaca fascicularis

Project start date: 2005-04-01

Project end date: 2009-03-31

5R01EY016371-03 (2007): $411475

5R01EY016371-02 (2006): $413792

1R01EY016371-01 (2005): $423750

INFORMATION TRANSFER IN THE LATERAL GENICULATE NUCLEUS

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Rockefeller University New York, Ny 100656399

Grant 5R01EY004888-03 from National Eye Institute, IRG: VISB

Abstract: The Lateral Geniculate Nucleus (LGN) is a major stage in the central visual pathway of higher animals. I5R01EY004888-10

Keywords: 1995

Project start date: 1984-09-01

Project end date: 1987-08-31

MATHEMATICAL ANALYSIS OF BRAIN FUNCTION

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Ophthalmologymount Sinai School Of Medicine Of Nyu
of New York University
new York, Ny 100296574

Grant 2R01MH050166-05A1 from National Institute Of Mental Health, IRG: CFN

Abstract: Our long-range objective is to understand the functional organization and dynamical activity of the cortex. The discovery of the columnar organization of the cortex has led to the notion that the columns are fundamental building blocks, from which larger functional units are constructed. The cortex is thus viewed as a crystal (a more or less regular array of repeating, similar modules. Our proposal will test and refine this modular hypothesis. We shall use optical imaging of the primary visual cortex of monkeys and cats, and simultaneously record electrical responses from small neuronal clusters and local field potentials. We shall thus obtain a spatio- temporal picture of the activity in the neural ensembles which encode various stimulus parameters. The data will be analyzed with extensions of Principal Component Analysis that we have developed. We address three major aims 1) To test the modularity hypothesis we shall measure, in a large piece of cortical tissue, the full range of functional maps ( for orientation, color, spatial frequency etc.) together with the retinotopic map. We shall measure the periodicity of, and correlations among, the functional maps, to determine if they are commensurate. This will lead to a refined framework that could include possibly incommensurate cortical scales and interactions among cortical elements. 2) We shall investigate how the Principal Components (eigenfunctions) obtained from the optical images depend on the extent of the visual stimulus, to determine how the dynamical dimension of the primary visual cortex (viewed as a dynamical system) scales with size. 3) We shall study the concerted electrical responses of neuronal clusters, to clarify the link between optical signals and neuronal activity, and to deepen our understanding of the neuronal dynamics. Our study is aimed at an intermediate architectural level, and deals with the way in which the fundamental modalities of the visual world (orientation, size, color and so on) are analyzed in the primary visual cortex. Such knowledge is crucial for the construction of cortical models, which are essential for any quantitative understanding of critical function and dysfunction

Keywords: brain electrical activity, brain mapping, brain visualization, computational neuroscience, neural information processing, visual cortex image processing, mathematical model, space perception, visual stimulus Macaca fascicularis, cat, charge coupled device camera, optics, stereotaxic technique

Project start date: 1994-09-30

Project end date: 2003-06-30

2R01MH050166-05A1 (1998): $330381

5R01MH050166-09 (2002): $366066

5R01MH050166-08 (2001): $406726

5R01MH050166-07 (2000): $346335

5R01MH050166-06 (1999): $349750

What Determines Thalamic Spatio-Temporal Properties?

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Neurosciencemount Sinai School Of Medicine Of Nyu

Grant 5R01EY016224-03 from National Eye Institute, IRG: CVP

Abstract: How do thalamic neurons integrate their various feedforward and feedback inputs? Most of the inputs and synapses in the mammalian lateral geniculate nucleus (LGN) are extra-retinal, but the way in which these diverse inputs are integrated to control the flow of visual information from retina to cortex is not understood. In particular, the influence of the descending inputs from the cortex and the perigeniculate nucleus (PGN) on the spatiotemporal properties of receptive fields of LGN relay neurons is unknown, although the size and complexity of these inputs strongly suggest their importance, without them, the LGN might arguably be unnecessary. To address this knowledge gap, we shall combine physiological experiments with computational modeling to achieve the following aims 1) Measure the spatiotemporal structure of receptive fields in the cat LGN before and during (reversible) inactivation of the descending feedback pathway from V1; 2) Compare spatial summation in the retina with that of LGN neurons with and without V1 feedback; 3) Measure the temporal transfer function of neurons in layer 6 of V1; 4) Construct computational models of LGN relay neurons that incorporate the descending pathway from V1 and the PGN, and 5) Validate the models´ predictions against physiological measurements. The proposed modeling, which builds on our initial (static) feedback model, will employ the innovative simulation approach of population kinetics, and will be one of the first attempts to model the corticothalamic feedback and its dynamics. It will use parallel computation on a scale not commonly found in neuroscience two clusters of powerful computers, and a very large IBM supercomputer, which can accommodate larger, more complex models than could have been attempted in the past. The results will advance our understanding of the role that the descending inputs to the LGN play in establishing its sensitivity, dynamics, receptive field structure and discharge pattern, and will provide a necessary stepping stone for future expansions of our evolving model of the early visual system. HEALTH RELEVANCE A more complete knowledge of how the LGN combines its diverse inputs, and especially how its temporal behavior depends on the cortex, should lead to insights into its role in dynamical brain diseases, such as epilepsy. More generally, an understanding of the role of feedback circuits will help us understand other dynamical pathologies, such as Parkinson´s disease

Project start date: 2006-09-01

Project end date: 2011-08-31

5R01EY016224-02 (2007): $411461

1R01EY016224-01A2 (2006): $423750

NEURONAL ACTIVITY AND OPTICAL SIGNALS IN THE BRAIN

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Mount Sinai School Of Medicine Of Nyu Of New York University New York, Ny 100296574

Grant 5R01EY012867-04 from National Eye Institute, IRG: ZRG1

Abstract: Adapted from the Investigator s ) The purpose of the proposed research is to determine the quantitative relationship between neural activity in the cortex and intrinsic optical signals (signals that do not require the application of dyes). Optical imaging of the cortex, especially of intrinsic optical signals, has been used extensively in the past decade to explore the functional organization in the brain, especially in the visual cortex. Some of the reported results have been surprising and some remain controversial. Despite the natural appeal of the technique and the wide attention that its results have attracted, very little is known in quantitative detail about the coupling between the neural activity and the intrinsic optical signal, which has several components. Such knowledge is crucial for the proper interpretation of the activity and selectivity selectivity maps obtained with optical imaging. An investigation of the following questions is proposed 1) What is the quantitative relationship between the neural activity and the optical signal? 2) Is the neural-optical relationship uniform across the cortex (isotropic)? 3) What aspects of neural activity (spikes, synaptic activity) are represented by the optical signal? 4) What is the contribution to the optical signal of the various functional or anatomical cell types in the cortex? The results of these studies will allow a quantitative interpretation of activity maps obtained not only by optical imaging, but also by other important imaging technologies that rely on the hemodynamic filter, such as fMRI and PET, which are now used not only in research but also as diagnostic tools in clinical practice.

Keywords: biological signal transduction, brain electrical activity, neural information processing, neuron, visual cortex, cell type, neurophysiology, synapse, visual stimulus, brain mapping, cat, computer data analysis, electrode, electrophysiology, functional magnetic resonance imaging, positron emission tomography

Project start date: 2000-03-08

Project end date: 2005-02-28

5R01EY012867-04 (2003): $242075

MATHEMATICAL ANALYSIS OF BRAIN FUNCTION

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Rockefeller University New York, Ny 100656399

Grant 5R01MH050166-02 from National Institute Of Mental Health, IRG: SRCM

Abstract: adapted from applicant s ) The long term goal of this research is to better understand the functional organization and dynamics of the cerebral cortex. It is proposed to optically record neuronal activity from the surface of the visual cortex of macaque monkeys, and apply to the data an extension of the Karhunen-Loeve principal component (or empirical eigenfunction) analysis.The investigators  preliminary analysis of such data has shown that seemingly noisy optical signals contain a small number of spatially segregated dynamical components. This study will 1) Establish whether these components correspond to known cortical structures or reveal new ones; 2) Search for visual stimuli that elicit only a single component in the response; 3) Investigate the contribution of known neuronal sub- populations (streams) to the optically-monitored neuronal activity by using visual stimuli that excite only certain cell populations, such as the magnocellular- projecting (M) cells, or only one class of photoreceptors; 4) Silence selected neuronal populations by injecting the local anesthetic Lidocaine into portions of the lateral geniculate nucleus (LGN); 5) Apply the same analysis techniques to data from neural models of the cortex, and show that the essence of the models can be captured by a much smaller set of dynamical equations (this should enable qualitative improvements in computational speed and data compression); and 6) show that the empirical eigenfunctions provide new objective measures of neuronal activity and connectivity applicable to relatively large cell populations.

Keywords: brain electrical activity, computational neuroscience, neural information processing, visual cortex, image processing, mathematical model, mathematics, visual stimulus, Macaca, computer simulation, electroencephalography, optics, parallel processing

Project start date: 1994-09-30

Project end date: 1995-11-30

5R01MH050166-02 (1995): $294840

1R01MH050166-01 (1994): $310250

PROJECT IV

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Mount Sinai School Of Medicine Of Nyu
of New York University
new York, Ny 100296574

Grant 1P50GM071558-01A20005 from National Institute Of General Medical Sciences, IRG: ZGM1

Project start date: 2007-09-18

Project end date: 2012-08-31

MATHEMATICAL ANALYSIS OF BRAIN FUNCTION

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Mount Sinai School Of Medicine Of Nyu Of New York University New York, Ny 100296574

Grant 5R01MH050166-04 from National Institute Of Mental Health, IRG: SRCM

Project start date: 1994-09-30

Project end date: 1998-06-30

5R01MH050166-04 (1996): $318461

FUNCTIONAL STREAMS IN THE PRIMATE VISUAL CORTEX

Ehud Kaplan, Jules And Doris Stein Research-to-preven
Mount Sinai School Of Medicine Of Cuny New York, Ny 10029

Grant 1R01EY011276-01A1 from National Eye Institute, IRG: ZRG1

Project start date: 1996-08-01

Project end date: 2001-07-31

1R01EY011276-01A1 (1996): $304544