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 NSERC RTI grant, with
Andrea Green, has been awarded! Time to go shopping…
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,
Cos,
Cos,
“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
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
Valeriya
Gritsenko: Research scientist 2008-2010, now assistant professor at the
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 April 3, 2016.