<span><span><br>Hola,<br> 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.
<br></span></span>Abajo va el resumen de la charla de hoy..<br><br> saludos,<br> martin<br><br><br> <br><strong><font size="4">Does the brain know when it changes?</font></strong><br><br>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 <a href="mailto:neurocenas@gmail.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">neurocenas@gmail.com</a> (o sea, no me contesten este mail a mi)
<br><br>resumen más abajo<br>mas info en: <a href="http://homepages.inf.ed.ac.uk/pseries/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
http://homepages.inf.ed.ac.uk/pseries/
</a><br><br>nos vemoss<br>d<br><span><span><br>Does</span> <span>
the</span> <span>brain</span> <span>know</span> <span>when</span> <span>it</span> <span>changes</span>?
<br><br><span name="st"><span name="st">abstract</span></span>:<br><br><span>The</span> properties of sensory neurons are not fixed. They
change dynamically according to <span>the</span> spatial and temporal context and
<span>the</span> task being performed. Adaptation, for example, is known to result in
a decrease in response amplitude, while attention enhances
responsivity.
<br>How <span>does</span> <span>the</span> rest of <span>the</span> <span>brain</span> interpret these <span>changes</span>? <span>
Does</span> <span>the</span> read-out adapt at <span>the</span> same time as <span>the</span> sensory neurons ?<br><br>We
explore this question in <span>the</span> context of sensory adaptation, focusing on
<span>the</span> examples of motion direction adaptation and contrast adaptation.
In our framework, perception is modeled as resulting from an encoder-decoder cascade.<br><span>The</span> encoder corresponds to <span>the</span> response properties of a population of cortical neurons and
<span>changes</span> during adaptation.<br>Different
types of decoders are considered, which are either fixed and 'unaware'
of <span>the</span> adaptation state, or which change dynamically at <span>the</span> same time
as <span>the</span> encoder, being thus always optimal and 'aware' of <span>the</span> adaptation state. <br>Their predictions are compared with <span>the</span> psychophysical data for estimation and discrimination tasks.
<br><br></span>We find that simple models of neural adaptation coupled with 'unaware' read-outs can account for <span>the</span> main features of <span>the</span>
psychophysical results. We discuss <span>the</span> 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.<span><br><br>Work in collaboration with E. <span name="st">Simoncelli</span> and A. Stocker (NYU).</span><br clear="all"><br>