Contributed Talk Sessions | Poster Sessions | All Posters | Search Papers

Poster Session A: Tuesday, August 12, 1:30 – 4:30 pm, de Brug & E‑Hall

Evidence accumulation across the senses in the face of causal uncertainty

Jochem Beurskens¹, Agata Wlaszczyk, Uta Noppeney²; ¹Donders Institute for Brain, Cognition and Behaviour, ²Radboud University

Presenter: Jochem Beurskens

Humans need to make accurate and timely decisions based on constant influx of noisy sensory signals. They should integrate signals from common causes, but segregate those from separate causes. Previous research has shown that the brain arbitrates between integration and segregation consistent with Bayesian Causal Inference models (BCI). However, these static models ignored the dynamics of perceptual decision making and therefore could not account for response times. Using psychophysics, we show that the influence of spatially disparate visual signals on observers' perceived sound location declines with longer response times. This pattern is best captured by a dynamic BCI model that accumulates evidence jointly about the signals' locations and their causal structure (i.e. common vs. independent causes) over time in a forgetful fashion, until a decisional threshold is reached. By accounting for both response choices and times these dynamic BCI models advance our understanding of how observers dynamically combine signals from multiple sensory modalities in the face of causal uncertainty. They provide a novel perspective on previous neuroimaging results showing a progression from fusion to BCI multisensory interactions along cortical pathways.

Topic Area: Brain Networks & Neural Dynamics

Extended Abstract: Full Text PDF