Systematic perceptual bias in delayed sensory discriminations reveal a dual inference system
Speaker: Itay Lieder
Reading (please read the paper before the meeting): https://www.nature.com/articles/s41593-018-0308-9?WT.feed_name=subjects_cognitive-neuroscience
Abstract: We developed a unified framework that captures both the influences of the immediate history (serial dependence) and the longer-term context that accounts for environment-optimized normative behaviour (contraction bias). Using our new analytical approach (Generalized Additive Model, GAM) , a dual system of inference is revealed– fast (flexibility and robustness) versus slower integration of previous events (a reliable estimate of the overall distribution of stimuli). The first component is affected by recent events that are confined to neighboring stimuli, and thus it increases the overall sensitivity to relevant environmental changes, regardless of the global distribution. The second component has a functional form that matches the expected pattern from an ideal observer with access to the stimulus distribution, resulting with optimal behavior in cases where the distribution is stationary. We further show that systemic abnormalities in this dual inference system can be associated with learning-impaired populations – autistic and dyslexic individuals, for whom reduced sensitivities to context were previously demonstrated.