[BIC-announce] Special Seminar in Biomedical Engineering - Schedule Change - Thursday December 8th at 12h30 - Room 333

[Christophe Grova]

Dear all

Just a reminder  we will have a special Biomedcial Engineering seminar 
TODAY at 12h30

Thursday  - December 8th,  at 12h30

Location: Room  333 Lyman Duff Building (Biomedical Engineering Dpt).

Speaker:  Dr. Gunnar Blohm, PhD Assistant Professor in Computational
Neuroscience, Queen's University

Title: Stochastic reference frame transformations affect multi-sensory
perception and action

Abstract:
Reference frame transformations are at the heart of sensory-to-motor
conversions and multi-sensory integration processes. This is because
different sensory signals are coded in different coordinates (e.g. vision in
retinal coordinates, proprioception in joint coordinates) which in turn can
be distinct from motor coordinates. Therefore, transforming information into
appropriate coordinate frames is crucial for multi-sensory perception and
movement planning. Reference frame transformations require estimates of body
geometry (e.g. angles of the eyes, head or arm) from sensory signals and/or
motor efference copies in order to evaluate the relative misalignment of the
reference frames. Since estimates of body geometry carry signal-dependent
noise, reference frame transformations can only be appropriately described
in statistical terms.
In my talk, I will discuss the nature and potential consequences of
stochastic reference frame transformations for perception and action. I will
explain how noise in rotation angles and axes affects the result of
reference frame transformations. I will show experimental data from reaching
experiments carried out under different coordinate frame misalignments. The
analysis of reach variability and reach endpoint distributions supports the
presence of signal-dependent noise in coordinate transformations. I will
also present findings testing whether signal-dependent noise in reference
frame transformations also affects multi-sensory perception. Finally, I will
demonstrate how multi-sensory integration weights change according to added
stochasticity in reference frame transformations.
In summary, noisy estimates of body geometry lead to stochastic reference
frame transformations. This signal-dependent noise affects sensory-motor
transformations, and multi-sensory perception leading to higher endpoint
variability, changes in multi-sensory weights and deviations in the
statistical distribution of data.





A list of upcoming seminars can be found at :
http://www.bme.mcgill.ca/seminars.html

See you there

Christophe Grova

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Christophe Grova, PhD
Assistant Professor
Biomedical Engineering Dpt
Neurology and Neurosurgery Dpt
Montreal Neurological Institute
Centre de Recherches en Mathématiques
Biomedical Engineering Department - Room 304
McGill University
3775 University Street, Montreal, Quebec, Canada, H3A 2B4
email : christophe.grova at mcgill.ca<mailto:christophe.grova at mcgill.ca>
tel : (514) 398 2516
fax : (514) 398 7461

web:
http://www.mni.mcgill.ca/research/gotman/members/christophe.html
http://www.bmed.mcgill.ca/
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