BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:Perception by "\;Patterns"\; in the Brain - Mush Okun\, Im perial College London DTSTART:20110727T140000Z DTEND:20110727T150000Z UID:TALK32195@talks.cam.ac.uk CONTACT:Microsoft Research Cambridge Talks Admins DESCRIPTION:The subject of the talk belongs to the area of computational n euroscience\, a new and rapidly evolving field of neuroscience whose aim i s to apply various computational tools to the study of the brain. Understa nding how the brain operates is one of the major challenges tackled by sci entists. Many theories have been suggested regarding how patterns of basic electrical signals become sensations of taste\, sight and sound.\n\nNeuro ns transmit information around the neural circuit as electrical pulses. Bu t how does the brain translate this information\, enabling us to perceive and understand the world? One theory posits that different types of inform ation are represented by patterned sequences of electrical charges across an array of neurons. According to this theory each perceived object genera tes a distinct pattern within the system of nerve cells for the brain to i nterpret. Each time the same object is viewed\, the neural circuit will cr eate an identical pattern in a precise and controlled manner.\n\nIn the ta lk I intend to discuss some experiments conducted to examine this theory. Specifically\, we studied how electrical potential fluctuations of\nindivi dual cortical neurons can precisely repeat during spontaneous activity\, s econds to minutes apart. These repeats\, also called cortical motifs\, wer e suggested to reflect a replay of sequential neuronal firing patterns. Ho wever\, a statistical analysis of three different types of stochastic surr ogate data that preserve dynamical characteristics of the recorded data\, revealed no evidence for the existence of deterministically generated cort ical motifs. Rather\, we suggest that the observed patterns occurred purel y by chance.\n\nAll the necessary biological background will be provided i n the first part of the talk.\n\nThe talk is based on the paper: Stochasti c emergence of repeating cortical motifs in spontaneous membrane potential fluctuations in vivo\, Mokeichev\, A. and Okun\, M. and Barak\, O. and Ka tz\, Y. and Ben-Shahar\, O. and Lampl\, I.\, Neuron 2007 LOCATION:Small lecture theatre\, Microsoft Research Ltd\, 7 J J Thomson Av enue (Off Madingley Road)\, Cambridge END:VEVENT END:VCALENDAR