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:
We are currently recruiting UdeM students for a stage d’ete during the summer of 2010. Please contact me if you are interested.
Lab Personnel:
Marie-Claude Labonté: Laboratory technician
Alexandre Pastor Bernier: PhD student
Ignasi Cos-Aguilera: Postdoctoral fellow
David Thura: Postdoctoral fellow
Valeriya Gritsenko: Research scientist
Alumni:
Thomas Michelet: Postdoctoral fellow
Jean-Philippe Thivierge: Postdoctoral fellow
Geneviève Aude Puskas: Stagiaire de recherche
Stephany El-Murr: Stagiaire de recherche
Current projects:
My
research projects are interdisciplinary, combining computational modeling with
experimental data. The basic plan is to develop models aimed at explaining
existing neural and behavioral data, use these models to make predictions that
inspire the design of future experiments, conduct the experiments, and use the
resulting data to modify and refine the models. Hopefully, this process will
converge on insights into how the brain does what it does so well.
Computational modeling of action specification and selection: Recent results suggest that multiple movement plans can be prepared in just as much detail as can a single movement plan, and that part of perception is the recognition of potential actions the world affords. In other words, when we look at the world we see it not merely in terms of what is out there, but in terms of what we can do out there. I’ve recently developed a computational model which suggests how the brain uses visual information to specify multiple potential actions across the cerebral cortex, and the processes by which these potential actions compete for overt execution. The model is a source of predictions for many of the experiments done in the lab.
Neural recording experiments: We are conducting a series of experiments involving multi-electrode recording from the cerebral cortex during reach decision tasks. These experiments are designed to elucidate the dynamics of the processes by which different potential actions compete for overt execution in the fronto-parietal network. Future experiments will examine whether choices can be influenced by subthreshold microstimulation in these regions.
Transcranial magnetic stimulation (TMS): We are using TMS to measure the corticospinal excitability of finger muscles during the preparatory period of a decision-making task. We predict that as a subject leans toward one or another choice, corticospinal excitability of the muscles used to make those choices will change in a reliable manner.
Guessing games: We are running behavioral experiments testing how human subjects make guesses as the information for or against a given choice is continuously changing. We analyze these results using models of decision-making, and are developing methods for computing the parameters of the model that best explain each subject’s behavior. These models will then be used to look for signatures of the decision-making process in the subject’s brain using fMRI.
Aperiodic synchronization: We are using simulated recurrent networks of integrate-and-fire neurons to examine the phenomenon of aperiodic synchronization. We find that this phenomenon arises under a small set of realistic assumptions, and may underlie a variety of behavioral abilities such as temporal memory and motor preparation.
Executing the choice: We are planning a series of experiments that investigate how the processes of decision-making can “spill out” into the planning and execution of movements. These experiments will make use of a robotic manipulandum (KINARM) used to measure and perturb the kinematics and dynamics of ongoing human movements.
History of the nervous system: I'm also working on some side-projects of a more philosophical nature. Most of these are concerned with developing a theory of behavior from the perspective of the evolutionary history of nervous systems. The human brain was not picked ready-made from a tree; it struggled to survive in the bodies of countless fish, frogs, rodents, etc. This was a long journey of many small steps, and its twists and turns laid down the organization of even the most advanced modern brains. Understanding that journey provides invaluable insights into the “big picture” of neural organization.
Sample Publications:
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]
Thivierge, J-P. and Cisek, P. (2008) “Non-periodic synchronization in heterogeneous networks of spiking neurons”. Journal of Neuroscience. 28(32): 7968-7978. [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. & 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]
Cisek, P. (2005)
“Neural representations of motor plans, desired trajectories, and
controlled objects”. Cognitive Processing. 6: 15-24. [PDF]
Cisek, P. & Kalaska, J.F. (2004) “Neural correlates of mental rehearsal in dorsal premotor cortex”. Nature 431: 993-996. [PDF]
Cisek, P., Crammond, D.J., and Kalaska, J.F. (2003) “Neural activity in primary motor and dorsal premotor cortex in reaching tasks with the contralateral versus ipsilateral arm”. Journal of Neurophysiology. 89 (2): 922-942. [PDF]
Cisek, P. (1999) “Beyond the computer metaphor: Behaviour as interaction”. Journal of Consciousness Studies. 6(11-12): 125-142. [PDF]
Cisek, P. and Scott, S.H. (1999) “An alternative interpretation of population vector rotation in macaque motor cortex”. Neuroscience Letters. 272: 1-4. [PDF]
Cisek, P. Grossberg, S., and Bullock, D. (1998) “A
cortico-spinal model of reaching and proprioception under multiple task
constraints”. The Journal of
Cognitive Neuroscience. 10(4): 425-444. [PDF]
Hobbies:
Computer programming, the piano (esp. Chopin), contemporary music, skiing, tennis, literature, science-fiction, movies, chess, go, computer games...
This page is permanently under construction. Last update was on September 28, 2009.