[CTN] CTN seminar: Prof. Len Maler, Sep 11, PAS 2464, 3:30

[Matthijs van der Meer]

Dear all,

Please join us for next Tuesday's CTN seminar (Sep 11) by Prof. Leonard
(Len) Maler, from the University of Ottawa. Title and abstract follow below.

Time and place are the usual, 3.30pm on Tuesday in PAS 2464.

If you would like to meet with Prof. Maler, and/or come to dinner
afterwards, please let me know.

Hope to see you all there for what should be an engaging talk by one of
Canada's most distinguished computational neuroscientists!

- Matt



Prof. Leonard Maler
Distinguished University Professor
Department of Cellular & Molecular Medicine (CMM)
Center for Neural Dynamics
University of Ottawa

http://www.neurodynamic.uottawa.ca/people-maler.html

Title: Multiple Encoding Strategies and the Computational burden of
Decoding for Perception

Abstract: Sensory systems of vertebrates typically have to encode many
distinct classes of signals emanating from conspecifics (communication),
food sources, predators, and environmental features required for
navigation (landmarks). Neuronal coding schemes associated with these
signal classes include labeled line coding, spike rate coding, spike
pattern coding, and population coding. Natural questions that arise are
whether there is any connection between the various classes of sensory
signals and the different coding types, and what neural dynamics might
implement these encoding/decoding strategies.

The electrosensory/motor system offers is a useful preparation to study
such problems because it is relatively simple to define and mimic the
natural signals associated with communication, prey capture and
navigation. Behavioral studies have revealed that the fish responds to
these signal classes and must therefore have the neuronal machinery for
their encoding, perceptual classification, and decoding into motor
activity. Presenting the fish with mimics of natural signals while
recording spiking responses have allowed us to trace encoding
transformations from electroreceptors to midbrain neurons.

We find that many disparate encoding strategies are differentially used
to encode signals associated with communication, prey detection and
landmark recognition. Labeled line coding is generally not present at
early sensory processing stages, but emerges in the midbrain as a result
of code sparsening. At early processing stages various combinations of
spike patterning, population coding and encoding via complex temporal
sequences of spiking responses across a population are required to
connect the electroreceptor responses and the final behavioral outcome
of sensory stimulation.