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SUMMARY:What the Rat's Whiskers Tell the Rat's Brain - Dr Rasmus Petersen\
 , Faculty of Life Sciences\, University of Manchester
DTSTART:20131022T150000Z
DTEND:20131022T160000Z
UID:TALK48482@talks.cam.ac.uk
CONTACT:Guillaume Hennequin
DESCRIPTION:The whisker system is beautifully organised and its microcircu
 itry is perhaps the best understood of any mammalian sensory system\, maki
 ng it an attractive model system for investigations in systems and computa
 tional neuroscience.  The focus of my group's work is the basic\nquestion 
 of how spike trains represent sensory events ('neural coding').\n\nIn any 
 sensory system\, the primary afferents constitute the first level of senso
 ry representation and fundamentally constrain all subsequent information p
 rocessing.  We have determined that neural coding in this system is based 
 on action potentials that are timed\nwith remarkable (sub-millisecond) pre
 cision.  We have also determined that the spike timing\, reliability and s
 timulus selectivity of primary afferents can be accurately described by a 
 simple Generalised Linear\nModel\, consisting of linear stimulus filtering
  combined with spike feedback.  The model accurately predicts not only the
  response of primary afferents to white noise whisker motion (median corre
 lation coefficient 0.92) but also to naturalistic\, texture-induced whiske
 r motion.  A 2-dimensional filter subspace\, corresponding to different mi
 xtures of position and velocity sensitivity\, captured 94% of the variance
  in the stimulus selectivity of the model.  Our results suggest that the f
 irst stage of the whisker system approximately tile a low-dimensional (2-3
 D) feature space.\n
LOCATION:Cambridge University Engineering Department\, CBL Rm #438 (http:/
 /learning.eng.cam.ac.uk/Public/Directions)
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