CiNet Monthly Seminar

2025年10月20日（月）
15:30-17:00
CiNet棟大会議室にて開催いたします。

15:30

演題：How time and probability shape the anticipation of imminent events

ドイツ
Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society
Post-Doctoral Scholar
Matthias Grabenhorst

Abstract:
The anticipation of events in time allows for action preparation and fast responses. This talk gives an overview of how abstract variables – the probabilities of whether and when sensory events will occur, and the time between sensory events – shape human anticipatory behavior. To predict when an event will occur, neural systems need to estimate elapsed time and event probability over time. According to a prominent hypothesis, neural systems fulfill these computational demands by estimating the hazard rate of events. Based on psychophysical experiments and computational modeling, we show that humans estimate a simpler variable: the event probability density function (PDF). Neural systems are imprecise clocks, introducing uncertainty to time estimation. A common hypothesis holds that temporal uncertainty linearly increases with time itself (Weber’s law). This implies independence between time estimation and event probability estimation. In contrast, we found that the event PDF modulates temporal uncertainty. The probability of whether an event will occur is another fundamental variable in temporal anticipation. We show that this static occurrence probability has a highly dynamic effect on anticipation over time. Finally, temporal warping of the event PDF (stretching/contracting) reveals timescale‑invariant anticipation in behavior, indicating that the system represents probability over time in a normalized coordinate. All of these results hold across audition and vision, suggesting modality-general mechanisms. The presented work contributes to a mechanistic understanding of temporal anticipation – a fundamental process underlying many cognitive domains.

16:15

演題：Oscillations: Their role in Canonical Principles of Human Brain Function & Behavior

ドイツ
Cooperative Brain Imaging Center (CoBIC), Goethe University Frankfurt
Professor
Georgios Michalareas

Abstract:
Neural oscillations provide a fundamental mechanism for organizing brain activity and shaping the core operations of human cognition. They structure communication across cortical networks, link perception with action, and regulate global brain states.
I will present evidence for their role in three canonical functions. First, oscillations mediate hierarchical processing: gamma rhythms carry feedforward sensory signals, while alpha/beta rhythms implement feedback influences, in line with anatomical connectivity. Second, oscillations underlie temporal anticipation: alpha and beta dynamics encode probabilistic event timing, supporting expectation and motor preparation. Third, oscillations mark state transitions such as recovery of consciousness, where frequency shifts capture a sharp change in intrinsic dynamics. These findings demonstrate that oscillations are central to the canonical principles of brain function.

担当 : 林 正道