Robert Knight, MD
Robert T. Knight, M.D., is the Evan Rauch Professor of Neuroscience and Director of the Helen Wills Neuroscience Center
Research Areas: Cognitive Neuroscience
The laboratory studies the contribution of prefrontal cortex to human behavior. We use electrophysiological, fMRI and behavioral techniques to study controls and neurological patients with frontal lobe damage in an effort to understand the neural mechanisms subserving cognitive processing in humans. The laboratory also records the electrocorticogram directly from the cortical surface in neurosurgical patients with implanted electrodes to study the electrophysiology of network activity supporting goal-directed behavior in humans. The laboratory uses this information to develop brain machine interfaces for motor and language prosthetic devices.
Human evolution is paralleled by a massive increase in the connectivity of the frontal cortex to other brain regions. The evolution of the prefrontal cortex is crucial for the development of human cognitive and social behavior. Damage to prefrontal cortex in humans from neurological or developmental disorders results in profound alterations in the ability to think, plan and interact in a socially appropriate manner. The laboratory is interested in the neural mechanisms by which frontal cortex controls distributed neuronal ensembles in other brain regions critical for both cognitive and social behavior. To achieve these aims the laboratory employs neuropsychological, neuroanatomical, electrophysiological and fMRI techniques to study the physiology of prefrontal function in normal subjects and in neurological patients.
The laboratory also records the electrocorticogram (ECoG) from neurosurgical patients during both acute intra-operative surgical procedures and in epileptic patients with subdural electrodes implanted for an extended period. This line of research aims to understand the network properties and neural coding supporting behavior in the human neocortex. The laboratory is actively developing the use of these ECoG signals for the development of brain-machine interfaces for motor and language prosthesis in neurological patients with disabling motor or language disorders.
Some broad areas under current investigation include: What is the timing and neural coding of interactions between prefrontal cortex and other brain regions engaged during attention and memory performance? What is the role of ultra-high cortical gamma oscillations and distributed network coherence in human behavior? Can ultra high gamma oscillations recorded from the human cortex be used to control robotic devices for paralyzed patients?
Knight, R.T. 1996. Contribution of human hippocampal region to novelty detection. Nature 383: 256-259.
Barcelo, P., Suwazono, S. and Knight, R.T. 2000. Prefrontal modulation of visual processing in humans. Nature Neuroscience. 3(4): 399-403.
Gehring, W.J. and Knight, R.T. 2000. Prefrontal - cingulate interactions in action monitoring. Nature Neuroscience. 3(5): 516-520.
Yonelinas, A.P., Kroll, N.E.A., Quamme, J.R., Lazzara, M.M., Sauve, M.J., Widaman, K.F. and Knight, R.T. 2002. Effects of extensive temporal lobe damage or mild hypoxia on recollection and familiarity. Nature Neuroscience 5(11): 1236-1241.
Muller, N.G., Machado, L. and Knight, R.T. 2002. Contribution of subregions of the prefrontal cortex to working memory: Evidence from brain lesions in humans. Journal of Cognitive Neuroscience 14(5): 673-686.
Beer, J.S., Heerey, E.A., Keltner, D., Scabini, D. and Knight, R.T. 2003. The regulatory function of self-conscious emotion: insights from patients with orbitofrontal damage. Journal of Personality and Social Psychology 8594: 594-604.
Bates, E., Wilson, S., Saygin, A.P., Dick, F., Sereno, M., Knight, R.T. and Dronkers, N.F. Assessing brain-behavior relationships using voxel based lesion-symptom mapping. Nature Neuroscience, 6(5):448-450, 2003.
Kramer, M.A., Edwards, E., Soltani, M., Knight, R.T., Berger, M.S. and Szerzi, A.J. Measures of linear and non-linear interdependence of electrocortigram time series from evoked-response potential experiments. Conf. Proc. IEEE Eng Med Biol Soc. 1:5558-561, 2004.
Kramer, M.A., Edwards, E., Soltani, M., Berger, M.S., Knight, R.T. and Szeri, A.J. 2004. Synchronization measures of bursting data: application to the electrocorticogram of an auditory event-related experiment. Physical Review E. 70(1): 011914-1-10.
Yamaguchi, S., Hale, L., D'Esposito, M. and Knight, R.T. 2004. Rapid prefrontal-hippocampal habituation to novel events. Journal of Neuroscience 24(23): 5356-5363.
Duarte, A.L., Ranganath, C. and Knight, R.T. 2005. Effects of unilateral prefrontal lesions on familiarity, recollection and source memory. Journal of Neuroscience 25(36): 8333-8337.
Edwards, E., Soltani, M., Deouell, L., Berger, M.S. and Knight, R.T. 2005. High gamma activity in response to deviant auditory stimuli recorded directly from human cortex. Journal of Neurophysiology 94(6): 4269-4280.
Canolty, R., Edwards, E., Soltani, M., Dalal, S.S., Kirsch, H.E., Barbaro, N.M., Berger, M.S. and Knight, R.T. High gamma power is phase-locked to theta oscillations in human neocortex. Science, 313: 1626-1628, 2006.
Canolty, R.C., Soltani, M.S., Dalal, S.S., Edwards, E., Barbaro, N.M., Dronkers, N.F., Nagarajan, S.S., Kirsch, H.E. and Knight, R.T. Spatiotemporal dynamics of word processing in the human brain. Frontiers in Neuroscience, 1(1): 185-196, 2007.
Deouell, L.Y., Heller, A., D'Esposito, M. Malach, R. and Knight, R.T. Cerebral responses to change in spatial location of unattended sounds. Neuron, 55(6): 985-996, 2007.
Fuhrmann Alpert, G., Hein, G, Tsai, N., Naumer, M.J. and Knight, R.T. Temporal Characteristics of audio-visual information flow. Journal of Neuroscience, 28(20): 5344-5349, 2008.
Knight, R.T. Consciousness Unchained: Ethical Issues and the Vegetative and Minimally Conscious State. American Journal of Bioethics, 8(9):1-2, 2008.
Loui, P., Wu, E.H., Wessel, D. L. and Knight, R.T. A generalized mechanism for perception of pitch patterns. Journal of Neuroscience, 29(2): 454-459, 2009.
Kishiyama, M.M., Boyce, W.T., Jimenez, A.M., Perry, L.M. and Knight, R.T. Socioeconomic disparities affect prefrontal function in children. Journal of Cognitive Neuroscience, 21:6, 1106-1115, 2009.