[Todos] Invitación charlas de Peggy Series (Neurociencia Computacional)

[Martin Graziano]

Hola,
        Peggy Series, investigadora del Institute for Adaptive and Neural
Computation, dará una charla hoy en la Facultad de Medicina a las 20.30hs, y
el próximo Jueves a las 12.30hs dará otra un poco más técnica en el
Laboratorio de Neurociencia Integrativa (Pabellón I, subsuelo). Están todos
cordialmente invitados.
Abajo va el resumen de la charla de hoy..

      saludos,
                 martin



*Does the brain know when it changes?*

La neurocena la hacemos en la Facultad de Medicina, sector Uriburu, 7mo
piso, timbre del Lab de Circuitos Neuronales a las 2030hs (puntual). Los que
quieran comer y beber manden un mail a neurocenas en gmail.com (o sea, no me
contesten este mail a mi)

resumen más abajo
mas info en: http://homepages.inf.ed.ac.uk/pseries/

nos vemoss
d

Does the brain know when it changes?

abstract:

The properties of sensory neurons are not fixed.  They change dynamically
according to the spatial and temporal context and the task being performed.
Adaptation, for example, is known to result in a decrease in response
amplitude, while attention enhances responsivity.
How does the rest of the brain interpret these changes? Does the read-out
adapt at the same time as the sensory neurons ?

We explore this question in the context of sensory adaptation, focusing on
the examples of motion direction adaptation and contrast adaptation.  In our
framework, perception is modeled as resulting from an encoder-decoder
cascade.
The encoder corresponds to the response properties of a population of
cortical neurons and changes during adaptation.
Different types of decoders are considered, which are either fixed and
'unaware' of the adaptation state, or which change dynamically at the same
time as the encoder, being thus always optimal and 'aware' of the adaptation
state.
Their predictions are compared with the psychophysical data for estimation
and discrimination tasks.

We find that simple models of neural adaptation coupled with 'unaware'
read-outs can account for the main features of the psychophysical results.
We discuss the significance of having read-outs that would be fixed on short
time scales compatible with adaptation, and their relevance in other
phenomena, such as center-surround contextual interactions, attention and
perceptual learning.

Work in collaboration with E. Simoncelli and A. Stocker (NYU).
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