David Richter
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davidrichter.bsky.social
David Richter
@davidrichter.bsky.social
Cognitive Neuroscientist | Predictive Processing & Perception Researcher.
At: CIMCYC, Granada. Formerly: VU Amsterdam & Donders Institute.
https://www.richter-neuroscience.com/
Taken together, our findings demonstrate that high-level visual predictions are rapidly integrated during perceptual inference. This suggests that the brain's predictive machinery is finely tuned to utilize expectations abstracted away from low-level sensory details, likely to facilitate perception.
June 26, 2025 at 10:22 AM
We also found a curious decrease in ERP amplitude by semantic (word-based) surprise. Critically, we found no modulation by low-level visual surprise, even though stimuli were predictable all the way down to the pixel level.
June 26, 2025 at 10:22 AM
Next, we turned to the key questions – when and what kind of surprise drive visually evoked responses? Results showed that neural responses around 200ms post-stimulus onset over parieto-occipital electrodes were selectively enhanced by high-level visual surprise.
June 26, 2025 at 10:22 AM
First, as a sanity check, we used RSA to show that the DNN and other models of interest (a semantic word-based and a task model) well explained the EEG response irrespective of surprise.
June 26, 2025 at 10:22 AM
We investigated these questions using EEG and a visual DNN. Participants viewed object images that were probabilistically predicted by preceding cues. We then quantified trial-by-trial surprise at low-levels (early DNN layers) and high-levels (late DNN layers) of visual feature abstraction.
June 26, 2025 at 10:22 AM
Predictive processing holds that the brain continuously generates predictions about incoming sensory information. But at what level of abstraction does the brain predict – edges & contrasts or high-level textures & objects? And which stages of visual processing do such predictions modulate?
June 26, 2025 at 10:22 AM