Victor Laboratory

Jonathan D. Victor, M.D., Ph.D.
Fred Plum Professor of Neurology

Our Mission

The mission of the laboratory is to advance the understanding of higher brain function at the level of circuits and systems, and how it is altered in disease.  We focus on sensory systems, including vision, gustation, and olfaction, as models to understand design principles for neural computations and sensorimotor integration, how these design principles are implemented in neural hardware, and how the properties of individual neurons relate to the function of large populations.

Lab Members

Mary Conte, PhD Senior Research Associate
Tamar Melman, Gradate Fellow
Yen-Chu Lin, , Graduate Fellow

Lab Webpage

http://www-users.med.cornell.edu/~jdvicto/labonweb.html

Goals

The laboratory’s long-term goals are to advance the understanding of how the brain carries out its integrative functions, and how these functions are affected by major neurologic disease. 

 

One main thrust of the research is directed at understanding the design principles of sensory processing, both in the sensory periphery and in the brain, and how these design principles are implemented in biological hardware.  We seek to determine the aspects of sensory information that are represented, the features of the activity of individual neurons and neural populations that support these representations, and realistic models for how these representations are transformed.  These questions are addressed primarily in the visual system, via neurophysiologic studies at the single-cell and multineuronal level (with Keith Purpura) and via psychophysical studies (with Mary Conte).  Experimental investigations are complemented by theoretical studies, including (a) the development of approaches to analyze multineuronal activity and (b) strategies for stimulus design that bridge the gap between methods motivated by analytical convenience, such as white noise and sinusoids, and methods based on ethologically relevant stimuli, such as natural scenes.

The second main thrust of the research is directed at understanding the derangements of integrative function in disease. In many neurologic diseases, including epilepsy and chronic brain injury, alterations in the dynamics of neuronal populations plays a major role in pathogenesis and/or symptomatology.  In conjunction with Nicholas Schiff and colleagues, we are analyzing EEG, functional imaging, and anatomical imaging in brain injury patients to probe these dynamics and their relationship to spontaneous and induced fluctuations in cognitive ability and behavior.  Population models of thalamocortical interactions play an important role in shaping the analytical approach. An integral part of the research is the development of dimension-reduction and statistical methods for analysis of multichannel datasets such as the EEG, which contain rich dynamical information, but also nonstationarity, noise, and artifacts with complex statistical structure.

Achievements

• Development of a class of approaches (“spike train metrics”) for analysis of neural data (with Keith Purpura)
• Development of a class of approaches (“binless embedding”) for assessing the information content of neural data
• Measurement of human visual sensitivity to a comprehensive set of local image features (with Mary Conte), and their correspondence to statistical regularities of natural images (with Vijay Balasubramanian and colleagues)
• Identification of the neural basis for visual sensitivity to high-order correlations, which in turn delineate image features
• Identification of a novel type of visual local motion signal (“glider motion”), and characterization of its occurrence in naturalistic movies 
• Delineating the mathematical underpinnings of how fixational eye movements decorrelate the retinal image (with Michele Rucci)
• Identification of a temporal code for the representation of taste (with Patricia Di Lorenzo)

Selected Recent Publications

For a complete listing, please see: http://www-users.med.cornell.edu/~jdvicto/labpubs.html

• Robust power spectral estimation for EEG data.  Journal of neuroscience methods. 2016 In Process
• Understanding the statistics of the natural environment and their implications for vision.  Vision research. 2016 In Process
• Spontaneous Changes in Taste Sensitivity of Single Units Recorded over Consecutive Days in the Brainstem of the Awake Rat.  PloS one. 2016 In Process
• A perceptual space of local image statistics.  Vision research. 2015 In Process
• A proposed role for routine EEGs in patients with consciousness disorders.  Annals of neurology. 2015 In Process
• The unsteady eye: An information-processing stage, not a bug.  Trends in neurosciences. 2015 In Process
• Visual processing of informative multipoint correlations arises primarily in V2.  eLife. 2015 In Process
• Preservation of electroencephalographic organization in patients with impaired consciousness and imaging-based evidence of command-following.  Annals of neurology.  2014 Academic Article
• Possible functions of contextual modulations and receptive field nonlinearities: pop-out and texture segmentation.  Vision research. 2014 In Process
• Large-scale brain dynamics in disorders of consciousness.  Current opinion in neurobiology. 2014 Review
• Post-stroke apathy and hypersomnia lead to worse outcomes from acute rehabilitation.  Translational stroke research. 2014 In Process
• Taste coding in the parabrachial nucleus of the pons in awake, freely licking rats and comparison with the nucleus of the solitary tract.  Journal of neurophysiology. 2014 In Process
• Responses to orientation discontinuities in V1 and V2: physiological dissociations and functional implications.  The Journal of neuroscience : the official journal of the Society for Neuroscience.  2014 Academic Article
• Cannabinoid neuromodulation in the adult early visual cortex.  PloS one. 2014 In Process
• The statistics of local motion signals in naturalistic movies.  Journal of vision.  2014 Academic Article

Secondary Appointments

Department of Neurology (WCMC)

Graduate Field Memberships

Neuroscience (WGSMS)
Physiology, Biophysics, and Structural Biology (WGSMS)
Graduate Field of Biomedical Engineering (Cornell-Ithaca)
Tri-institutional Program in Computational Biology
Tri-institutional MD/PhD Program

Adjunct Faculty Appointments

Laboratory of Biophysics, The Rockefeller University

Hospital Appointments

The New York Presbyterian Hospital
The Rockefeller University Hospital

Collaborators

Keith Purpura
Nicholas Schiff
Sheila Nirenberg
Michele Rucci
Patricia DiLorenzo

Focus Areas: 

Systems Neurology & Computational Neuroscience

Lab Head(s): 

Victor, Jonathan