BME Kognitív Szeminárium Meghívó

A BME Kognitív Tudományi Tanszék szeretettel vár mindenkit tanszéki szeminárium sorozatának következő hétfői előadására <http://cogsci.bme.hu/Esem.php?esemIndex=66>: The Department of Cognitive Science at BME cordially invites you to the next talk <http://cogsci.bme.hu/Esem.php?esemIndex=66> in its lecture series: * * *Nádasdy Zoltán * Post-Doctoral Fellow The Andersen Lab California Institute of Technology ** <http://www.vis.caltech.edu/%7Ezoltan/cv2007v2.htm> <http://www.vis.caltech.edu/%7Ezoltan/cv2007v2.htm> <http://biology.caltech.edu/> /*The neuronal phase code* (Encoding and decoding information by the phase of action potentials)/// December 8., hétfő - 15:00. BME, XI., Stoczek u. 2., St. ép., 320.-as terem. Monday, December 8th, 15:00. BME, Budapest, Stoczek u. 2, St. building, room 320. *Abstract: * Experimental evidence, such as task-dependent coherency between single-unit activity and local field potentials (LFPs), together with the dependency of action potential (AP) initiation on the subthreshold membrane oscillation (SMO) suggest that: i) the probability of action potentials is controlled by a common oscillatory mechanism; ii) the SMOs across individual neurons are not independent but rather form a coherent field of oscillations; and iii) nearly-synchronized SMOs may propagate through neuronal connections, creating a constant-phase gradient of SMO between neighbor neurons. Based on these assumptions, we formulated a model in which neurons encode information by the phase of APs relative to the SMO. The model consists of four stages: encoding with phase, gamma alignment, information transfer, and reconstruction. We demonstrated by means of simulations that information encoded by the phase of APs can reliably be transferred and reconstructed at distant target areas. Moreover, since the phase code is a compressed representation of the spatio-temporal features of the stimulus, it enables the transfer of information in parallel pathways without distortion from conductance differences. We illustrate by examples how phase coding may account for a number of unresolved physiological observations related to sparse coding, motion processing, phase precession, and invariance detection, as well as anatomical principles, such as the columnar organization and grid cell architecture. Furthermore, we show empirical evidence for stimulus-dependent phase coding in V1 from simultaneous single-unit and LFP recordings.* * Keresztes Attila BME-Kognitív Tudományi Tanszék BME-Cognitive Science Department akeresztes(a)cogsci.bme.hu <mailto:akeresztes@cogsci.bme.hu> keresztes.attila(a)gmail.com <mailto:keresztes.attila@gmail.com>