Thursday, September 10th, at 12:00 in C209 and on Zoom, Nobuaki Mizumoto (Evolutionary Genomics Unit led by Tom Bourguignon) will give a Talk on "Evolutionary perspectives of collective behavior in termites"

Speaker:  Chris Bowman, University of Kent

Title: Tautological p-Kazhdan–Lusztig Theory for cyclotomic Hecke algebras

Abstract: We discuss a new explicit isomorphism between (truncations of) quiver Hecke algebras and Elias–Williamson’s diagrammatic endomorphism algebras of Bott–Samelson bimodules. This allows us to deduce that the decomposition numbers of these algebras (including as examples the symmetric groups and generalised blob algebras) are tautologically equal to the associated p-Kazhdan–Lusztig polynomials, provided that the characteristic is greater than the Coxeter number. This allows us to give an elementary and explicit proof of the main theorem of Riche–Williamson’s recent monograph and extend their categorical equivalence to cyclotomic Hecke algebras, thus solving Libedinsky–Plaza’s categorical blob conjecture.

An OIST neuroscience online seminars (ONOS) talk.

Abstract

The visual system is a complex, hierarchically-organised information processing network. Counter-intuitively, successive areas contain less information about a scene, but neural activity is structured to better represent specific information. For example, neurons in primate area MT convey little colour information, but motion direction can be linearly decoded from their activity. The ongoing activity of individual neurons is highly variable, meaning reliable computation depends on collaborative processing across neural populations. However, it remains unclear how visual information is reliably represented across neurons within an area, and how these representations are transformed between areas to extract specific stimulus properties. To address this, we record visually-evoked activity simultaneously from dozens of neurons in V1 and MT in marmosets.

We use decoding techniques to predict stimulus orientation or direction from activity across a neural population. This has allowed us to show that neural representations are affected by stimulus history: recent motion biases predictions in a manner consistent with perceptual illusions; and luminance and contrast changes affect orientation coding, again in a manner consistent with human sensitivity.

We study inter-area communication by comparing the timing of action potentials in V1 with local field potentials (LFP, a population measure of local dendritic activity) in MT. We have shown that action potentials preferentially occur at specific phases of the LFP, and that motion information is best communicated from V1 to MT at specific phases.

Collectively, this suggests that hierarchical information processing depends on action potentials in privileged subsets of neurons occurring in privileged time windows.

Zoom details

Zoom Meeting link:
https://oist.zoom.us/j/95700149323?pwd=VWQxY0FGQmxVQmtUTVZ2SXRnMGx6dz09

Meeting ID: 957 0014 9323
Passcode: 855303

Hoban et al. (2020) "Impact of α-synuclein pathology on transplanted hESC-derived dopaminergic neurons in a humanized α-synuclein rat model of PD" PNAS, 117 (26) 15209-15220.

Reviewed/presented for the journal club by Professor Gordon Arbuthnott from the Brain Mechanism for Behaviour Unit.

Zoom Meeting link:
https://oist.zoom.us/j/95700149323?pwd=VWQxY0FGQmxVQmtUTVZ2SXRnMGx6dz09

Meeting ID: 957 0014 9323
Passcode: 855303

PhD Public Presentation

Language: English

Reservation required

Application Deadline: Sep 2 (Wed)