Dragoi Lab
2335
22
About Our Lab
Our Team
Despite major advances in understanding the properties of single cells and molecule-level processes, how the cerebral cortex operates at the circuit level continues to remain mysterious. For the past several decades, neuroscientists have observed remarkable regularity in the neural architecture: cortical areas communicate through feedforward, lateral, and feedback connections. Clearly, understanding the functional principles of cortical communication is key to understanding how the entire cortex operates.
Research Objectives
My laboratory has embarked on a quest to understand the principles behind the network encoding of sensory information and executive control in cerebral cortex. Our long-range goal is to understand the mechanisms underlying state and experience-dependent changes in the function of cortical populations and how the coordination of distributed networks of neurons influences behavior.
Our Approach
To accomplish these goals, we combine electrophysiological (multi-electrode recording in restrained and freely moving non-human primates), optogenetic and electrical stimulation, behavioral approaches, and computational methods. Our basic strategy is to help develop new tools for modulating and recording population activity across cortical circuits in restrained and unrestrained animals and then apply these techniques to examine the neural computations and coding principles across cortical circuits.
Research
State and experience-dependent changes in cortical networks underlying behavioral decisions
One of our long-standing interests is to understand the relationship between the activity of populations of cortical cells and behavioral decisions. Our working hypothesis is that the accuracy of sensory representation and intracortical communication determines the accuracy of behavioral responses.
Optogenetic manipulation of cortical circuits
Viral tools for gene delivery have allowed new optogenetic methods to target cells based on cell localization and connectivity. Physiological dissection of targeted circuits, primarily by depolarizing or hyperpolarizing rhodopsins, has been extremely successful in the mouse brain, but remain of limited use in non-human primate (NHP) and human brain. We have just started a series of projects to test the function of cortical circuits by manipulating their responses and then examine the impact on perceptual decision making.
Real-time network interactions underlying complex behavior in freely moving animals
It has become increasingly understood that studying the brain in a restrained laboratory rig poses severe limits on our capacity to understand the function of brain circuits. To overcome these limitations, we have constructed a wireless system that allows us to study cortical dynamics at the population level while nonhuman primates are moving freely in their natural environment. Phenomena that were difficult or impossible to observe in an experimental rig, such as foraging, sleep, or social behavior are now possible to study.
Contact Information
Valentin Dragoi
Laboratory Head
email: vdragoi@houstonmethodist.org
tel: 346.238.2640
Rosemary and Daniel J. Harrison III Presidential Distinguished Chair in Neuroprosthetics
Houston Methodist Research Institute
6670 Bertner Avenue
Houston, TX 77030
Professor of Electrical and Computer Engineering
Rice University
6100 Main Street
Houston, TX 77005
Professor of Neuroscience,
Brain and Mind Research Institute
Weill Cornell Medical College
1300 York Avenue
New York, NY 10065
Jobs
Position for Postdoctoral Fellow
A full-time postdoctoral fellow position in systems neuroscience is immediately available in Dr. Valentin Dragoi’s laboratory in the Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas at Houston. This position offers opportunities for combining multiple-electrode recordings in the visual and prefrontal cortices of non-human primates, optogenetics, behavioral, and computational approaches. The ideal candidate would have a strong background in systems and/or computational neuroscience as well as experience with neurophysiological recording techniques.
Knowledge of Matlab, C++, and statistical modeling would be a plus. Completion of the PhD degree in neuroscience, psychology, engineering, physics, or related field is required before the start date. Our institution offers a first-class training and research environment in systems and computational neuroscience, and a highly collaborative environment with scientists at Baylor College of Medicine, Rice University, and University of Houston.
To apply, please send a CV and brief statement of research interests to Mitchell Slapik and Ariana Andrei with the subject line "Post-doc Position."
Position for Research Assistant
A full-time research assistant position in systems neuroscience is immediately available in Dr. Valentin Dragoi’s laboratory in the Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas at Houston. This position offers opportunities for combining multiple-electrode recordings in the visual and prefrontal cortices of non-human primates, optogenetics, behavioral, and computational approaches. The ideal candidate would have a strong background in systems and/or computational neuroscience as well as experience with neurophysiological recording techniques.
Knowledge of Matlab, C++, and statistical modeling would be a plus. Completion of a bachelor's degree in neuroscience, psychology, engineering, physics, or related field is required before the start date. Our institution offers a first-class training and research environment in systems and computational neuroscience, and a highly collaborative environment with scientists at Baylor College of Medicine, Rice University, and University of Houston.
To apply, please send a CV and brief statement of research interests to Mitchell Slapik and Ariana Andrei with the subject line "Research Assistant."
Contact Information
Valentin Dragoi
Laboratory Head
email: vdragoi@houstonmethodist.org
tel: 346.238.2640
Rosemary and Daniel J. Harrison III Presidential Distinguished Chair in Neuroprosthetics
Houston Methodist Research Institute
6670 Bertner Avenue
Houston, TX 77030
Professor of Electrical and Computer Engineering
Rice University
6100 Main Street
Houston, TX 77005
Professor of Neuroscience,
Brain and Mind Research Institute
Weill Cornell Medical College
1300 York Avenue
New York, NY 10065
Jobs
A full-time postdoctoral fellow position in systems neuroscience is immediately available in Dr. Valentin Dragoi’s laboratory in the Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas at Houston. This position offers opportunities for combining multiple-electrode recordings in the visual and prefrontal cortices of non-human primates, optogenetics, behavioral, and computational approaches. The ideal candidate would have a strong background in systems and/or computational neuroscience as well as experience with neurophysiological recording techniques.
Knowledge of Matlab, C++, and statistical modeling would be a plus. Completion of the PhD degree in neuroscience, psychology, engineering, physics, or related field is required before the start date. Our institution offers a first-class training and research environment in systems and computational neuroscience, and a highly collaborative environment with scientists at Baylor College of Medicine, Rice University, and University of Houston.
To apply, please send a CV and brief statement of research interests to Mitchell Slapik and Ariana Andrei with the subject line "Post-doc Position."
Position for Research Assistant
A full-time research assistant position in systems neuroscience is immediately available in Dr. Valentin Dragoi’s laboratory in the Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas at Houston. This position offers opportunities for combining multiple-electrode recordings in the visual and prefrontal cortices of non-human primates, optogenetics, behavioral, and computational approaches. The ideal candidate would have a strong background in systems and/or computational neuroscience as well as experience with neurophysiological recording techniques.
Knowledge of Matlab, C++, and statistical modeling would be a plus. Completion of a bachelor's degree in neuroscience, psychology, engineering, physics, or related field is required before the start date. Our institution offers a first-class training and research environment in systems and computational neuroscience, and a highly collaborative environment with scientists at Baylor College of Medicine, Rice University, and University of Houston.
To apply, please send a CV and brief statement of research interests to Mitchell Slapik and Ariana Andrei with the subject line "Research Assistant."
Funding Sources
Funding Sources
Selected Publications
-
Kharas, N., Chelaru, M., Eagleman, S., Parajuli, A., Dragoi, V. NREM sleep improves behavioral performance by desynchronizing cortical circuits. Science 386, 892-897 (2024).
-
Shahidi, N., Franch, M., Parajuli, A., Schrater, P., Wright, A., Pitkow, X., Dragoi, V. Population coding of strategic variables during foraging in freely moving macaques. Nature Neuroscience (2024).
-
Franch, M., Yellapantula, S., Parajuli, A., Kharas, N., Wright, A., Aazhang, B., Dragoi, V. Visuo-frontal interactions during social learning in freely moving macaques. Nature (2024).
-
Andrei, A., Akil, A., Kharas, N., Rosenbaum, R., Josić, K., Dragoi, V. Rapid compensatory plasticity revealed by dynamic correlated activity in monkeys in vivo. Nature Neuroscience 26, 1960–1969 (2023).
-
Parajuli, A., Gutnisky, D., Tandon, N., Dragoi, V. Endogenous fluctuations in cortical state selectively enhance different modes of sensory processing in human temporal lobe. Nature Communications 14, 5591 (2023).
-
Debes, S., Dragoi, V. Suppressing feedback signals to visual cortex abolishes attentional modulation. Science, 379:6631, 468-473 (2023).
-
Nigam, S., Milton, R., Pojoga, S., Dragoi, V. Adaptive coding across visual features during free-viewing and fixation conditions. Nature Communications, 14:87 (2023).
-
Kharas, N., Andrei, A., Debes, S., Dragoi, V. Brain state limits propagation of neural signals in laminar cortical circuits. Proceedings of the National Academy of Sciences of the United States of America, 119:30 (2022).
-
Chelaru, M., Eagleman, S., Andrei, A., Milton, R., Kharas, N., Dragoi, V. High-order interactions explain the collective behavior of cortical populations in executive but not sensory areas. Neuron, 109:24, 3954-3961 (2021).
-
Andrei, A., Debes, S., Chelaru, M., Liu, X., Rodarte, E., Spudich, J., Janz, R., Dragoi, V. Heterogeneous side effects of cortical inactivation in behaving animals. eLife, 10 (2021).
-
Nigam, S., Pojoga, S., Dragoi, V. A distinct population of heterogeneously color-tuned neurons in macaque visual cortex. Science Advances, 7:8 (2021).
-
Pojoga, S., Kharas, N., Dragoi, V. Perceptually unidentifiable stimuli influence cortical processing and behavioral performance. Nature Communications, 11:6109 (2020).
-
Milton, R., Shahidi, N. Dragoi, V. Dynamic states of population activity in prefrontal cortical networks of freely-moving macaque. Nature Communications, 11:1948 (2020).
-
Nigam, S., Pojoga, S., Dragoi, V. Synergistic Coding of Visual Information in Columnar Networks. Neuron, 104:2, 402-411.e4 (2019).
-
Andrei, A.R., Pojoga, S., Janz, R., Dragoi, V. Integration of cortical population signals for visual perception. Nature Communications, 10:3832 (2019).
-
Shahidi, N., Andrei, A.R., Hu, M., Dragoi, V. High-order coordination of cortical spiking activity modulates perceptual accuracy. Nature Neuroscience, 22, 1148-1158 (2019).
-
Fernandez-Leon, J., Hasen, B., Dragoi, V. Representation of Rapid Image Sequences in V4 Networks. Cerebral Cortex, 28:8, 2675-2684 (2018).
-
Gutnisky, D., Beaman, C., Lew, S., Dragoi, V. Cortical response states for enhanced sensory discrimination. eLife, 6 (2017).
-
Beaman, C., Eagleman, S., Dragoi, V. Sensory coding accuracy and perceptual performance are improved during the desynchronized cortical state. Nature Communications, 8:1308 (2017).
-
Slater, J., Chelaru, M., Hansen, B., Beaman, C., Kalamangalam, G., Tandon, N., Dragoi, V. Focal Changes to Human Electrocorticography With Drowsiness: A Novel Measure of Local Sleep. The Journal of Neuropsychiatry and Clinical Neurosciences, 29:3, 236-247 (2017).
-
Gutnisky, D., Beaman, C., Lew, S., Dragoi, V. Spontaneous Fluctuations in Visual Cortical Responses Influence Population Coding Accuracy. Cerebral Cortex, 27:2, 1409-1427 (2017).
-
Chelaru, M., Hansen, B., Tandon, N., Conner, C., Szukalski, S., Slater, J., Kalamangalam, G., Dragoi, V. Reactivation of visual-evoked activity in human cortical networks. Journal of Neurophysiology, 115:6, 3090-100 (2016).
-
Wang, Y., Dragoi, V. Rapid learning in visual cortical networks. eLife, 4 (2015).
-
Fernandez-Leon, J., Parajuli, A., Franklin, R., Sorenson, M., Felleman, D., Hansen, B., Hu, M., Dragoi, V. A wireless transmission neural interface system for unconstrained non-human primates. Journal of Neural Engineering, 12:5 (2015).
-
Chelaru, M., Dragoi, V. Negative Correlations in Visual Cortical Networks. Cerebral Cortex, 26:1, 246-56 (2014).
-
Hansen, B., Chelaru, M., Dragoi, V. Correlated variability in laminar cortical circuits. Neuron, 76:3, 590-602 (2012).
-
Eagleman, S., Dragoi, V. Image sequence reactivation in awake V4 networks. Proceedings of the National Academy of Sciences of the United States of America, 109:47, 19450-5 (2012).
-
Onken, A., Dragoi, V., Obermayer, K. A maximum entropy test for evaluating higher-order correlations in spike counts. PLoS Computational Biology, 8:6 (2012).
-
Hansen, B., Eagleman, S., Dragoi, V. Examining local network processing using multi-contact laminar electrode recording. Journal of Visualized Experiments, 55:2806 (2011).
-
Wang, Y., Iliescu, B. Ma, J., Josić., K, Dragoi, V. Adaptive changes in neuronal synchronization in macaque V4. The Journal of Neuroscience, 31:37, 13204-13 (2011).
-
Hansen, B., Chelaru, M., Dragoi, V. Correlated Variability in Laminar Cortical Circuits. Neuron, 76:3, 590-602 (2012).
-
Gutnisky, D., Hansen, B., Iliescu, B., Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19:7, 555-60 (2009).
-
Chelaru, M., Dragoi, V. Efficient coding in heterogeneous neuronal populations. Proceedings of the National Academy of Sciences of the United States of America, 105:42, 16344-9 (2008).
-
Gutnisky, D., Dragoi, V. Adaptive coding of visual information in neural populations. Nature, 452, 220-224 (2008).
-
Chelaru, M., Dragoi, V. Asymmetric Synaptic Depression in Cortical Networks. Cerebral Cortex, 18:4, 771-788 (2008).
-
Dragoi, V., Sur, M. Image Structure at the Center of Gaze during Free Viewing. Journal of Cognitive Neuroscience, 18:5, 737-748 (2006).
-
Jin, D., Dragoi, V., Sur, M., Seung, H. Tilt aftereffect and adaptation-induced changes in orientation tuning in visual cortex. Journal of Neurophysiology, 94:6, 4038-50 (2005).
-
Sharma, J., Dragoi, V., Tenenbaum, J., Miller, E., Sur, M. V1 neurons signal acquisition of an internal representation of stimulus location. Science, 300:5626, 1758-1763 (2003).
-
Dragoi, V., Sharma, J., Sur, M. Response plasticity in primary visual cortex and its role in vision and visuomotor behaviour: Bottom-up and top-down influences. IETE Journal of Research, 49, 1-9 (2003).
-
Dragoi, V., Staddon, J., Palmer, R., Buhusi, C. Interval timing as an emergent learning property. Psychological Review, 110:1, 126-44 (2003).
-
Dragoi, V., Sharma, J., Miller, E., Sur, M. Dynamics of neuronal sensitivity in visual cortex and local feature discrimination. Nature Neuroscience, 5, 883-891 (2002).
-
Dragoi, V. A feedforward model of suppressive and facilitatory habituation effects. Biological Cybernetics, 86, 419-426 (2002).
-
Sur, M., Schummers, J., Dragoi, V. Cortical plasticity: time for a change. Current Biology, 12:5, R168-70 (2002).
-
Dragoi, V., Turcu, C., Sur, M. Stability of cortical responses and the statistics of natural scenes. Neuron, 32:6, 1181-92 (2001).
-
Dragoi, V., Rivadulla, C., Sur, M. Foci of orientation plasticity in visual cortex. Nature, 411, 80-86 (2001).
-
Dragoi, V., Sharma, J., Sur, M. Adaptation-induced plasticity of orientation tuning in adult visual cortex. Neuron, 28:1, 287-98 (2000).
-
Dragoi, V., Sur, M. Dynamic properties of recurrent inhibition in primary visual cortex: contrast and orientation dependence of contextual effects. Journal of Neurophysiology, 83:2, 1019-30 (2000).
-
Dragoi, V., Staddon, J. The dynamics of operant conditioning. Psychological Review, 106:1, 20-61 (1999).
-
Dragoi, V., Lockhead, G. Context-dependent changes in visual sensitivity induced by Müller-Lyer stimuli. Vision Research, 39:9, 1657-1670 (1999).
For a full list of our publications, please visit our Google Scholar.
Selected Publications
-
Kharas, N., Chelaru, M., Eagleman, S., Parajuli, A., Dragoi, V. NREM sleep improves behavioral performance by desynchronizing cortical circuits. Science 386, 892-897 (2024).
-
Shahidi, N., Franch, M., Parajuli, A., Schrater, P., Wright, A., Pitkow, X., Dragoi, V. Population coding of strategic variables during foraging in freely moving macaques. Nature Neuroscience (2024).
-
Franch, M., Yellapantula, S., Parajuli, A., Kharas, N., Wright, A., Aazhang, B., Dragoi, V. Visuo-frontal interactions during social learning in freely moving macaques. Nature (2024).
-
Andrei, A., Akil, A., Kharas, N., Rosenbaum, R., Josić, K., Dragoi, V. Rapid compensatory plasticity revealed by dynamic correlated activity in monkeys in vivo. Nature Neuroscience 26, 1960–1969 (2023).
-
Parajuli, A., Gutnisky, D., Tandon, N., Dragoi, V. Endogenous fluctuations in cortical state selectively enhance different modes of sensory processing in human temporal lobe. Nature Communications 14, 5591 (2023).
-
Debes, S., Dragoi, V. Suppressing feedback signals to visual cortex abolishes attentional modulation. Science, 379:6631, 468-473 (2023).
-
Nigam, S., Milton, R., Pojoga, S., Dragoi, V. Adaptive coding across visual features during free-viewing and fixation conditions. Nature Communications, 14:87 (2023).
-
Kharas, N., Andrei, A., Debes, S., Dragoi, V. Brain state limits propagation of neural signals in laminar cortical circuits. Proceedings of the National Academy of Sciences of the United States of America, 119:30 (2022).
-
Chelaru, M., Eagleman, S., Andrei, A., Milton, R., Kharas, N., Dragoi, V. High-order interactions explain the collective behavior of cortical populations in executive but not sensory areas. Neuron, 109:24, 3954-3961 (2021).
-
Andrei, A., Debes, S., Chelaru, M., Liu, X., Rodarte, E., Spudich, J., Janz, R., Dragoi, V. Heterogeneous side effects of cortical inactivation in behaving animals. eLife, 10 (2021).
-
Nigam, S., Pojoga, S., Dragoi, V. A distinct population of heterogeneously color-tuned neurons in macaque visual cortex. Science Advances, 7:8 (2021).
-
Pojoga, S., Kharas, N., Dragoi, V. Perceptually unidentifiable stimuli influence cortical processing and behavioral performance. Nature Communications, 11:6109 (2020).
-
Milton, R., Shahidi, N. Dragoi, V. Dynamic states of population activity in prefrontal cortical networks of freely-moving macaque. Nature Communications, 11:1948 (2020).
-
Nigam, S., Pojoga, S., Dragoi, V. Synergistic Coding of Visual Information in Columnar Networks. Neuron, 104:2, 402-411.e4 (2019).
-
Andrei, A.R., Pojoga, S., Janz, R., Dragoi, V. Integration of cortical population signals for visual perception. Nature Communications, 10:3832 (2019).
-
Shahidi, N., Andrei, A.R., Hu, M., Dragoi, V. High-order coordination of cortical spiking activity modulates perceptual accuracy. Nature Neuroscience, 22, 1148-1158 (2019).
-
Fernandez-Leon, J., Hasen, B., Dragoi, V. Representation of Rapid Image Sequences in V4 Networks. Cerebral Cortex, 28:8, 2675-2684 (2018).
-
Gutnisky, D., Beaman, C., Lew, S., Dragoi, V. Cortical response states for enhanced sensory discrimination. eLife, 6 (2017).
-
Beaman, C., Eagleman, S., Dragoi, V. Sensory coding accuracy and perceptual performance are improved during the desynchronized cortical state. Nature Communications, 8:1308 (2017).
-
Slater, J., Chelaru, M., Hansen, B., Beaman, C., Kalamangalam, G., Tandon, N., Dragoi, V. Focal Changes to Human Electrocorticography With Drowsiness: A Novel Measure of Local Sleep. The Journal of Neuropsychiatry and Clinical Neurosciences, 29:3, 236-247 (2017).
-
Gutnisky, D., Beaman, C., Lew, S., Dragoi, V. Spontaneous Fluctuations in Visual Cortical Responses Influence Population Coding Accuracy. Cerebral Cortex, 27:2, 1409-1427 (2017).
-
Chelaru, M., Hansen, B., Tandon, N., Conner, C., Szukalski, S., Slater, J., Kalamangalam, G., Dragoi, V. Reactivation of visual-evoked activity in human cortical networks. Journal of Neurophysiology, 115:6, 3090-100 (2016).
-
Wang, Y., Dragoi, V. Rapid learning in visual cortical networks. eLife, 4 (2015).
-
Fernandez-Leon, J., Parajuli, A., Franklin, R., Sorenson, M., Felleman, D., Hansen, B., Hu, M., Dragoi, V. A wireless transmission neural interface system for unconstrained non-human primates. Journal of Neural Engineering, 12:5 (2015).
-
Chelaru, M., Dragoi, V. Negative Correlations in Visual Cortical Networks. Cerebral Cortex, 26:1, 246-56 (2014).
-
Hansen, B., Chelaru, M., Dragoi, V. Correlated variability in laminar cortical circuits. Neuron, 76:3, 590-602 (2012).
-
Eagleman, S., Dragoi, V. Image sequence reactivation in awake V4 networks. Proceedings of the National Academy of Sciences of the United States of America, 109:47, 19450-5 (2012).
-
Onken, A., Dragoi, V., Obermayer, K. A maximum entropy test for evaluating higher-order correlations in spike counts. PLoS Computational Biology, 8:6 (2012).
-
Hansen, B., Eagleman, S., Dragoi, V. Examining local network processing using multi-contact laminar electrode recording. Journal of Visualized Experiments, 55:2806 (2011).
-
Wang, Y., Iliescu, B. Ma, J., Josić., K, Dragoi, V. Adaptive changes in neuronal synchronization in macaque V4. The Journal of Neuroscience, 31:37, 13204-13 (2011).
-
Hansen, B., Chelaru, M., Dragoi, V. Correlated Variability in Laminar Cortical Circuits. Neuron, 76:3, 590-602 (2012).
-
Gutnisky, D., Hansen, B., Iliescu, B., Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19:7, 555-60 (2009).
-
Chelaru, M., Dragoi, V. Efficient coding in heterogeneous neuronal populations. Proceedings of the National Academy of Sciences of the United States of America, 105:42, 16344-9 (2008).
-
Gutnisky, D., Dragoi, V. Adaptive coding of visual information in neural populations. Nature, 452, 220-224 (2008).
-
Chelaru, M., Dragoi, V. Asymmetric Synaptic Depression in Cortical Networks. Cerebral Cortex, 18:4, 771-788 (2008).
-
Dragoi, V., Sur, M. Image Structure at the Center of Gaze during Free Viewing. Journal of Cognitive Neuroscience, 18:5, 737-748 (2006).
-
Jin, D., Dragoi, V., Sur, M., Seung, H. Tilt aftereffect and adaptation-induced changes in orientation tuning in visual cortex. Journal of Neurophysiology, 94:6, 4038-50 (2005).
-
Sharma, J., Dragoi, V., Tenenbaum, J., Miller, E., Sur, M. V1 neurons signal acquisition of an internal representation of stimulus location. Science, 300:5626, 1758-1763 (2003).
-
Dragoi, V., Sharma, J., Sur, M. Response plasticity in primary visual cortex and its role in vision and visuomotor behaviour: Bottom-up and top-down influences. IETE Journal of Research, 49, 1-9 (2003).
-
Dragoi, V., Staddon, J., Palmer, R., Buhusi, C. Interval timing as an emergent learning property. Psychological Review, 110:1, 126-44 (2003).
-
Dragoi, V., Sharma, J., Miller, E., Sur, M. Dynamics of neuronal sensitivity in visual cortex and local feature discrimination. Nature Neuroscience, 5, 883-891 (2002).
-
Dragoi, V. A feedforward model of suppressive and facilitatory habituation effects. Biological Cybernetics, 86, 419-426 (2002).
-
Sur, M., Schummers, J., Dragoi, V. Cortical plasticity: time for a change. Current Biology, 12:5, R168-70 (2002).
-
Dragoi, V., Turcu, C., Sur, M. Stability of cortical responses and the statistics of natural scenes. Neuron, 32:6, 1181-92 (2001).
-
Dragoi, V., Rivadulla, C., Sur, M. Foci of orientation plasticity in visual cortex. Nature, 411, 80-86 (2001).
-
Dragoi, V., Sharma, J., Sur, M. Adaptation-induced plasticity of orientation tuning in adult visual cortex. Neuron, 28:1, 287-98 (2000).
-
Dragoi, V., Sur, M. Dynamic properties of recurrent inhibition in primary visual cortex: contrast and orientation dependence of contextual effects. Journal of Neurophysiology, 83:2, 1019-30 (2000).
-
Dragoi, V., Staddon, J. The dynamics of operant conditioning. Psychological Review, 106:1, 20-61 (1999).
-
Dragoi, V., Lockhead, G. Context-dependent changes in visual sensitivity induced by Müller-Lyer stimuli. Vision Research, 39:9, 1657-1670 (1999).
Dragoi Lab News
- Live from the brain: Visual cues inform decision to cooperate
-
Debes and Dragoi Published in Science
-
Research from Dragoi lab on cortical adaptation published in Nature Communications
- Dr. Dragoi and the Dragoi Lab Published in Proceedings of the National Academy of Sciences
-
Research in Dragoi lab on cortical populations published in Neuron
-
Dragoi lab research provides new insight into cortical inactivation manipulations
-
Research on color-tuned neurons published in Science Advances
-
Dragoi’s pioneering research published in Nature Communications
-
Kharas Recipient of 2020 Dean’s Research Scholarship Award
-
Dragoi’s Visual Perception Research Published in Nature Communications
-
Dragoi Publishes Research on Brain Synergy
-
Franch's research showcased at SfN 2019
-
Dragoi lab published in Nature Neuroscience
-
Debes receives inaugural Terry J. Crow Scholarship
-
Dragoi earns third NIH BRAIN award
- Dr. Valentin Dragoi To Receive EUREKA Award From NIH
Dragoi Lab News
- Live from the brain: Visual cues inform decision to cooperate
-
Debes and Dragoi Published in Science
-
Research from Dragoi lab on cortical adaptation published in Nature Communications
- Dr. Dragoi and the Dragoi Lab Published in Proceedings of the National Academy of Sciences
-
Research in Dragoi lab on cortical populations published in Neuron
-
Dragoi lab research provides new insight into cortical inactivation manipulations
-
Research on color-tuned neurons published in Science Advances
-
Dragoi’s pioneering research published in Nature Communications
-
Kharas Recipient of 2020 Dean’s Research Scholarship Award
-
Dragoi’s Visual Perception Research Published in Nature Communications
-
Dragoi Publishes Research on Brain Synergy
-
Franch's research showcased at SfN 2019
-
Dragoi lab published in Nature Neuroscience
-
Debes receives inaugural Terry J. Crow Scholarship
-
Dragoi earns third NIH BRAIN award
- Dr. Valentin Dragoi To Receive EUREKA Award From NIH
Our Team
Valentin Dragoi, Principal Investigator
Dr. Dragoi examines how networks of cortical neurons encode information and how the population code influences behavioral decisions in real time. Research in his laboratory combines electrophysiological (multi-electrode recording in restrained and freely moving animals, optical and electrical stimulation), behavioral, and computational methods. He received rigorous training in experimental and theoretical neuroscience. His goals are to understand the neuronal computations and coding principles of cortical circuits and develop new technologies for high-yield neuronal recording of brain activity.
Research Scientists
Mircea Chelaru, PhD
Mircea received his B.Sc. in Electrical engineering and his PhD in computer sciences at Polytechnic Institute, Iasi, Romania. He was a post-doctoral fellow at Duke University and then in Univ of Western Ontario from 2004-2006. Since 2009, Mircea has been a research scientist at Dragoi lab.
Sorin Pojoga, PhD
Sorin received his BSc in Physics from Bucharest University, Romania and his PhD in Astrophysics & Space Sciences from Université Denis Diderot – Paris VII, Paris, France. After working at the Astronomical Institute, Bucharest, Romania and Prairie View A&M University, Sorin joined the Dragoi Lab in 2006.
Sunny Nigam, PhD
Color is one of the most important aspects of natural images that humans encounter in everyday life. It guides perceptions and eventually actions. Sunny's focus is on understanding how higher visual areas like V4 encode color information and how this might be affected by adaptation. Prior to working in the Dragoi lab, Sunny went to graduate school in the Physics department at Indiana University, Bloomington, where he worked under the supervision of John Beggs. Sunny's research involved computing functional connectivity from high density multi-electrode array recordings of in-vitro and in-vivo neural populations.
Postdoctoral Fellows
Ariana Andrei, PhD
Upon completing her Masters in neuroscience from McGill University, Ariana moved to Houston for her PhD. Her dissertation used optogenetics in non-human primates to study how neuronal populations create sensory perceptions. In 2017, she started her post-doctoral work at the Dragoi lab.
Research Engineer
Arun Parajuli, MS
Arun received his BE in Computer Engineering at Tribhuvan University, Nepal, and his MS in Software Engineering at Texas Tech University. He is currently conducting research on how visual information is represented in visual areas V4 and dlPFC of freely roaming primates. Before this, he used micro-electric stimulation to induce sleep-like activity, electrocorticography (ECoG) to understand cortical states and intrinsic optical imaging to investigate orientation and color maps in visual areas V2 and V4.
PhD Students
Alexandra McConnnell
Alexandra graduated from the University of Texas with a BS in neuroscience where she worked in Dr. MacKenzie Howard's lab studying disrupted synaptic plasticity in genetic epilepsy models of Dravet Syndrome. She started at GSBS in 2020 and joined the Dragoi lab where she is interested in the neurophysiology of social interaction in non-human primates.
Mitchell Slapik
Mitchell studies neuroscience in the MD/PhD program at McGovern Medical School. He graduated with high honors in philosophy at Swarthmore College and completed the post-bac premedical program at Johns Hopkins, where he worked in Dr. Cherie Marvel's lab examining how the cerebellum contributes to cognition. In the Dragoi lab, he uses machine learning to better understand how the brain processes visual information.
Madison Shyer
Madison graduated from Fordham University with a BS with research honors in psychology and bioethics in 2020. She worked as a research assistant at the Houston Methodist Research Institute and a research coordinator at UTHealth Dept. of Neurology before joining GSBS in 2022. She is interested in cognitive neuroscience and cortical interactions in learning in primates.
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