My brain.MePaul Cisek Ph.D.

Department of Neuroscience
University of Montréal
2960 chemin de la tour, room 4117
Montréal (Québec) H3T 1J4 Canada
Phone: 514-343-6111 x4355
FAX: 514-343-2111
E-mail:

 

 


Research interests:

I am interested in how the brain controls behavior. Many scientists approach this very large question by starting with perception and asking how the brain builds an internal representation of the world, and how it then uses this representation to guide action. In contrast, I study behavior by starting with a concrete task such as a voluntary movement and asking what parameters of the task the brain must specify and control, and what information from the environment it may employ toward that specification. The goal here is an understanding of brain mechanisms for mediating interaction with the world, not necessarily of mechanisms for representing the world. A research program based on such an approach begins with questions concerning motor control and gradually works its way toward the perceptual systems which guide that control. One could say I'm going backwards through the brain...

Please check out my Curriculum Vitae.


News:

Our core CIHR grant has been renewed for another 5 years! This means that I am recruiting new students. Please contact me if you’re interested. The first priority is to find somebody for a computational project, in which we use very high-dimensional (>400D) neural spaces to analyze population activity during dynamic decision-making.


Projects:

“Affordance competition hypothesis”

Classical theories in psychology suggest that behavior consists of serial processes of computing representations of the world from sensory information, using those representations to build knowledge and make decisions, and then finally executing motor actions that implement those decisions. However, these classic concepts are difficult to reconcile with the growing body of neurophysiological data. Instead, we and others have proposed that the basic functional architecture of behavior is parallel – and that the brain is continuously using sensory information to specify potential actions available in the world (“affordances”) while at the same time collecting cues for selecting which one is most appropriate at a given moment. This very general hypothesis makes a number of specific predictions, which we are testing through behavioral, neurophysiological, and computational projects.

Cisek, P. and Kalaska, J.F. (2010) “Neural mechanisms for interacting with a world full of action choices”. Annual Review of Neuroscience. 33: 269-298. [PDF]

Cisek, P. (2007) “Cortical mechanisms of action selection: The affordance competition hypothesis” Philosophical Transactions of the Royal Society B. 362: 1585-1599. [PDF] [suppl]

Cisek, P. (2006) “Integrated neural processes for defining potential actions and deciding between them: A computational model”. Journal of Neuroscience. 26(38): 9761-9770. [PDF] [suppl]

Cisek, P. (1999) “Beyond the computer metaphor: Behaviour as interaction”. Journal of Consciousness Studies. 6(11-12): 125-142. [PDF]

 

“Biased competition in sensorimotor maps”

A key prediction of the affordance competition hypothesis is that the brain can represent multiple potential actions in parallel within the same regions that are involved in executing those actions during overt behavior, and these parallel representations compete against each other during decision-making. This competition is influenced by a variety of biases, such as reward value and effort, and unfolds within a “sensorimotor map” that reflects the geometry of the immediate environment. This project tests this prediction through multi-cellular recording of neural activity in premotor cortex.

Pastor-Bernier, A., Tremblay, E., and Cisek, P. (2012) “Dorsal premotor cortex is involved in switching motor plans”. Frontiers in Neuroengineering. 5(5). doi: 10.3389/fneng.2012.00005. [PDF]

Pastor-Bernier, A. and Cisek, P. (2011) “Neural correlates of biased competition in premotor cortex”. Journal of Neuroscience. 31(19): 7083-7088. [PDF] [suppl]

Cisek, P. & Kalaska, J.F. (2005) “Neural correlates of reaching decisions in dorsal premotor cortex: specification of multiple direction choices and final selection of action”. Neuron. 45(5): 801-814. [PDF]

 

“The biomechanics of choices”

When playing a sport, we are faced with a myriad of decisions between different possible actions, and the best choice depends not only on potential outcomes but also on the effort associated with each action. This project tests how human subjects take the biomechanical costs of making different movements into account when selecting between actions. It uses behavioral methods as well as transcranial magnetic stimulation (TMS) to probe the evolving decision in the human motor cortex.

Cos, I., Duqué, J. and Cisek, P. (in press) “Rapid prediction of biomechanical costs during action decisions” Journal of Neurophysiology. [preprint]

Cos, I., Medleg, F., and Cisek, P. (2012) “The modulatory influence of endpoint controllability on decisions between actions” Journal of Neurophysiology. 108(6): 1764-80. [PDF]

Cos, I., Bélanger, N., and Cisek, P. (2011) “The influence of predicted arm biomechanics on decision-making”. Journal of Neurophysiology. 105(6): 3022-3033. [PDF]

 

“Urgency-gating model”

To deal with a constantly changing world, the brain must quickly process sensory information and make a variety of trade-offs between the speed of a decision and its accuracy. Within the context of affordance competition, we hypothesize that the process of deliberating between different action options takes places through a competition occurring within the sensorimotor system (premotor and primary motor cortex), combining three sources of information: Spatial information about potential actions (from visual and parietal cortex); evidence in favor of one action versus another (from prefrontal cortex); and a growing signal related to the urge to make a movement (from the basal ganglia). When the competition within these sensorimotor regions is resolved, the brain commits to a choice and releases the selected movement. We are testing predictions of this hypothesis through behavioral studies with humans, as well as neural recordings in premotor, motor and prefrontal cortex as well as the basal ganglia.

Thura, D. and Cisek, P. (2014) “Deliberation and commitment in the premotor and primary motor cortex during dynamic decision-making” Neuron. 81(6): 1401-1416. [PDF][suppl]

Thura, D., Beauregard-Racine, J., Fradet, C-W., and Cisek, P. (2012) “Decision-making by urgency-gating: Theory and experimental support” Journal of Neurophysiology. 108(11): 2912-30. [PDF]

Cisek, P., Puskas, G.A., and El-Murr, S. (2009) “Decisions in changing conditions: The urgency-gating model”. Journal of Neuroscience. 29(37): 11560-11571. [PDF]

NOTE: I am recruiting a student for computational studies evolving out of this project.

 

“Decision-making through a distributed consensus”

Classical theories propose that decisions are made by a “central executive” system that resides in the frontal lobes and commands other parts of the brain, such as the motor system, to execute its goals. However, according to our affordance competition hypothesis, the competition between different potential actions occurs at many loci throughout the cerebral cortex and subcortical regions, and the “tipping point” leading to a particular choice can come from any of these regions. This predicts that the order in which a decision appears in the brain can depend on context. We are testing this prediction through simultaneous neural recordings in the premotor and parietal cortex.

Cisek, P. (2012) “Making decisions through a distributed consensus”. Current Opinion in Neurobiology. 22(6): 927-936. [PDF]

 


Current Lab Personnel:

Marie-Claude Labonté: Laboratory technician 2006-

David Thura: Postdoctoral fellow 2008-

Matthew Carland: Master’s student 2011-

Ayuno Nakahashi: Master’s student 2013-

Alumni:

Alexandre Pastor-Bernier: PhD student 2007-2012, now postdoctoral fellow at Cambridge University with Wolfram Schultz

Thomas Michelet: Postdoctoral fellow 2006-2008, now assistant professor at the Université de Bordeaux 2

Jean-Philippe Thivierge: Postdoctoral fellow 2006-2007, now assistant professor at the University of Ottawa

Valeriya Gritsenko: Research scientist 2008-2010, now assistant professor at the University of West Virginia

Ignasi Cos: Postdoctoral fellow 2008-2012, now research scientist at the Université Pierre & Marie Curie, Paris

Geneviève Aude Puskas: Stagiaire de recherche 2006

Stephany El-Murr: Stagiaire de recherche 2007

Nicolas Bélanger: Stagiaire d’été 2009

Julie Beauregard-Racine: Stagiaire d’été 2009

Farid Medleg: Stagiaire de recherche 2010

Charles-William Fradet: Stagiaire d’été 2010

Elsa Tremblay: Stagiaire d’été 2011

Jessica Trung: Stagiaire d’été 2013

Jean-François Cabana: Stagiaire d’été 2014


This page is permanently under construction. Last update was on August 13, 2014.