We aim to advance our understanding of the nature of the operations performed by primary visual cortex, and how these operations are carried out. The research plan is organized around two basic questions. A. Are the spatial computations performed by neurons in V1 adequately described by oriented receptive fields, simple nonlinearities, and gain controls, or, conversely, do more complex spatial operations play an important role? B. Can firing rate of a local population be considered the main carrier of visual information, or, conversely, is the fine structure of neural activity (across time or across a local population) also important? Question A is motivated by growing experimental evidence that the operations performed by V 1 neurons are indeed complex. The experimental strategy described here uses new stimuli, precisely balanced in space and spatial frequency - in contrast to traditional stimuli, that are highly localized in space but broad in spatial frequency (e.g., spots and bars), or extended in space but highly localized in spatial frequency (e.g., gratings). Pilot studies using the new stimuli demonstrate response patterns not anticipated from standard models - including shifts in the balance of linear and nonlinear influences, and shifts in orientation tuning. The stimulus set is a hierarchy of patterns that are progressively less restricted in their combined space bandwidth aperture. The patterns that are the most restricted in space-bandwidth aperture are Gaussians and profiles that resemble edges and lines. As the space-bandwidth aperture is broadened, intrinsically two-dimensional patterns and """"""""non-Cartesian"""""""" patterns emerge, thus suggesting that our approach will also be useful beyond V1. Question B builds on our identification of the statistical features of the fine structure of neural activity that are reliably correlated with visual stimuli. We now propose to determine whether these features indeed influence the activity of downstream neurons. Our approach relies on a combination of multiple-neuron recordings via tetrodes, and experimental results and analytic tools that emerged during the previous funding period. Together, these investigations will advance the understanding of neural computations that lead to extraction of features and objects from the visual image.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY009314-15
Application #
7236581
Study Section
Special Emphasis Panel (ZRG1-IFCN-E (02))
Program Officer
Oberdorfer, Michael
Project Start
1991-07-01
Project End
2009-06-30
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
15
Fiscal Year
2007
Total Cost
$407,833
Indirect Cost
Name
Weill Medical College of Cornell University
Department
Neurology
Type
Schools of Medicine
DUNS #
060217502
City
New York
State
NY
Country
United States
Zip Code
10065
Joukes, Jeroen; Yu, Yunguo; Victor, Jonathan D et al. (2017) Recurrent Network Dynamics; a Link between Form and Motion. Front Syst Neurosci 11:12
Hu, Qin; Victor, Jonathan D (2016) Two-Dimensional Hermite Filters Simplify the Description of High-Order Statistics of Natural Images. Symmetry (Basel) 8:
Yu, Yunguo; Schmid, Anita M; Victor, Jonathan D (2015) Visual processing of informative multipoint correlations arises primarily in V2. Elife 4:e06604
Rucci, Michele; Victor, Jonathan D (2015) The unsteady eye: an information-processing stage, not a bug. Trends Neurosci 38:195-206
Schmid, Anita M; Victor, Jonathan D (2014) Possible functions of contextual modulations and receptive field nonlinearities: pop-out and texture segmentation. Vision Res 104:57-67
Frey, Hans-Peter; Schmid, Anita M; Murphy, Jeremy W et al. (2014) Modulation of early cortical processing during divided attention to non-contiguous locations. Eur J Neurosci 39:1499-507
Schmid, Anita M; Purpura, Keith P; Victor, Jonathan D (2014) Responses to orientation discontinuities in V1 and V2: physiological dissociations and functional implications. J Neurosci 34:3559-78
Menda, Gil; Shamble, Paul S; Nitzany, Eyal I et al. (2014) Visual perception in the brain of a jumping spider. Curr Biol 24:2580-5
Ohiorhenuan, Ifije E; Mechler, Ferenc; Purpura, Keith P et al. (2014) Cannabinoid neuromodulation in the adult early visual cortex. PLoS One 9:e87362
Schiff, N D; Shah, S A; Hudson, A E et al. (2013) Gating of attentional effort through the central thalamus. J Neurophysiol 109:1152-63

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