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.
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 on decision processes distributed throughout the sensorimotor system. 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.
Pezzulo, G. and Cisek, P. (2016) “Navigating the affordance landscape: Feedback control as a process model of behavior and cognition”. Trends in Cognitive Sciences. 20(6): 414-424. [PDF]
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. (1999) “Beyond the computer metaphor: Behaviour as interaction”. Journal of Consciousness Studies. 6(11-12): 125-142. [PDF]
The affordance competition hypothesis suggests that the brain can represent multiple potential actions in parallel within the same regions 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. Our work with former student Alexandre Pastor-Bernier confirmed two key predictions: 1) that reward values influence activity in premotor cortex, but only when there is a choice to be made; and 2) that the competition between two very different actions is stronger than a competition between similar actions. In our newest project, led by doctoral student Ayuno Nakahashi, we are testing whether decisions are made by a “central executive” or through a “distributed consensus” across the cortical network. This involves simultaneous neural recordings in the premotor and parietal cortex, using two semi-chronically implanted microdrives each with 32 independently moveable electrodes.
Cisek, P. (2012) “Making decisions through a distributed consensus”. Current Opinion in Neurobiology. 22(6): 927-936. [PDF]
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]
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]
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, transcranial magnetic stimulation (TMS) to probe the evolving decision in the human motor cortex, and (in collaboration with Andrea Green) galvanic vestibular stimulation to test the influence of one’s body motion on their action choices.
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 have been 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.
Carland M., Marcos, E., Thura, D., and Cisek, P. (2016) “Evidence against perfect integration of sensory information during perceptual decision-making” Journal of Neurophysiology. 115(2): 915-930. [PDF]
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]
Marie-Claude Labonté: Laboratory technician 2006-
David Thura: Postdoctoral fellow 2008-
David has been leading the behavioral and neural projects testing and refining the urgency-gating model
Matthew Carland: Doctoral student 2013-
Matthew’s doctoral project studies the relationship between urgency (as quantified in our simple decision tasks) and the psychological trait of impulsivity in humans.
Ayuno Nakahashi: Doctoral student 2015-
Ayuno is leading our new simultaneous neural recordings in premotor and parietal cortex, testing for the existence or absence of a central executive in the primate brain.
Julien Michalski: Master’s student 2016-
Julien is pioneering a new line of research in our lab, investigating how we make decisions about actions while we’re already acting, as during natural behavior.
Tim Meehan: Postdoctoral fellow 2016-
Tim is examining neural activity during decision-making from intracranial EEG electrodes in human subjects awaiting epilepsy surgery.
Simon Haché: Master’s student 2017- (co-supervised with Andrea Green)
Simon is investigating how we select movements around obstacles and how those choices are influenced by our own self motion.
Thomas Lusignan: Undergraduate research intern 2018
Thomas is performing analyses of local field potentials from the premotor and parietal cortex of monkeys as they resolve decision conflicts.
Thomas Michelet: Postdoctoral fellow 2006-2008, now an assistant professor at the Université de Bordeaux 2
Jean-Philippe Thivierge: Postdoctoral fellow 2006-2007, now an associate professor at the University of Ottawa
Research scientist 2008-2010, now assistant professor at the
Ignasi Cos: Postdoctoral fellow 2008-2012, now research scientist at the Universitat Pompeu Fabra, Barcelona
Geneviève Aude Puskas: Undergraduate research intern 2006
Stephany El-Murr: Undergraduate research intern 2007
Nicolas Bélanger: Undergraduate research intern 2009
Julie Beauregard-Racine: Undergraduate research intern 2009
Farid Medleg: Undergraduate research intern 2010
Charles-William Fradet: Undergraduate research intern 2010
Elsa Tremblay: Undergraduate research intern 2011
Jessica Trung: Undergraduate research intern 2013
Jean-François Cabana: Undergraduate research intern 2014
Albert Feghaly: Undergraduate research intern 2015
Guido Guberman: Visiting undergraduate intern 2015
Philippe Canstonguay: Undergraduate research intern 2016
Pierre-Éric Cazeau: Undergraduate research intern 2017
This page is permanently under construction. Last update was on December 30, 2017.