Biology subjects

Yon, D.

Publications and source records attributed to Yon, D..

4 recordsLinked to original sources

bioRxiv2026

Paradoxical influences of prediction are resolved across time

It is widely thought that our brains use expectations to optimise perception, yet theoretical accounts disagree about the form of this optimisation. Bayesian accounts propose that perception is biased towards expected events, rapidly generating more veridical experiences, whereas cancellation accounts argue that unexpected inputs are perceptually prioritised as they are more informative. A recent opposing process theory reconciles these views by proposing a temporal reversal in prioritisation: perceptual processing is pre-emptively biased towards what is expected, followed by later enhancement of only particularly surprising inputs that are informative for learning and model updating. Here, we tested this account using time-resolved decoding of EEG data, while participants observed avatar action outcomes that were either expected or unexpected based on their own movements. Expectation effects on the neural representations of these action outcomes indeed unfolded over time in such a manner, with higher decoding for task-relevant expected outcomes starting before stimulus onset, followed by a later post-stimulus advantage for unexpected outcomes. These findings support the opposing process theory, demonstrating a reversal in prioritisation that is not predicted by current Bayesian or cancellation accounts. By exerting distinct influences across time, expectations can thus render perception veridical, while still allowing for the accurate perception of particularly unexpected events that are important for updating our beliefs or ongoing courses of action. Significance statementHow we perceive the world is shaped by our expectations. Yet it remains unclear how the brain can use these expectations to make perception both more accurate and more informative, given these demands require opposite influences of expectation on processing - upweighting versus downweighting the expected, respectively. Here, we show that this apparent conflict is resolved across time. The expected is enhanced before a stimulus appears by pre-activating what we expect, whereas unexpected inputs are enhanced later. This temporal reversal allows expectations to support both demands, rapidly generating generally more accurate perceptual experiences, while also remaining sensitive to unexpected information that is critical for learning and adaptive behaviour.

neuroscience↗

bioRxiv2025

Perceptual predictions track subjective, over objective, statistical structure

Over the past two decades, converging evidence from neuroscience and psychology has shown that predictions based on learnt statistical regularities exert a widespread influence on perception, action and cognition. Predictive processes in cognition and the brain are usually modelled as tracking objective event probabilities, deriving predictions and prediction errors from the statistical structure of the environment. However, our subjective models of our environments do not always align with these objective statistics. Currently we know little about how these subjective representations may determine the predictive functions. To separate subjective and objective contributions to prediction, we conducted three studies where cues (actions or tones) predicted visual outcomes (shapes or Gabors) with varying contingencies, and adult participants discriminated these outcomes. Uniquely to our paradigm, participants also reported their experiences of the statistical structure embedded in the task - the subjective probability (Experiment 1; N = 68), expectedness (Experiment 2; N = 35), or surprise (Experiment 3; N = 35) associated with the outcomes. When modelling subjective ratings alongside objective structure, the speed of perceptual decisions was best explained by independent, additive contributions of both. The decision itself was usually only explained by the subjective ratings, with little additional variance explained by objective statistical structure. These findings suggest that subjective experience may play a key, overlooked role in predictive processes, and open a host of interesting questions about the relative objective and subjective contributions to prediction, perception, and learning.

animal behavior and cognition↗

bioRxiv2023

Predictions and errors are distinctly represented across V1 layers

Predictive processing frameworks of cortical functioning propose that neural populations in different cortical layers serve distinct roles in representing the world. There are distinct testable theories within this framework that we examined with a 7T fMRI study, where we contrasted responses in primary visual cortex (V1) to expected (75% likely) and unexpected (25%) Gabor orientations. Multivariate decoding analyses revealed an interaction between expectation and layer, such that expected events could be decoded with comparable accuracy across layers, while unexpected events could only be decoded in superficial laminae. These results are in line with predictive processing accounts where expected virtual input is injected into deep layers, while superficial layers process the error with respect to expected signals. While this account of cortical processing has been popular for decades, such distinctions have not previously been demonstrated in the human sensory brain. We discuss how both prediction and error processes may operate together to shape our unitary perceptual experiences.

neuroscience↗

bioRxiv2020

Action enhances predicted touch

It is widely believed that predicted tactile action outcomes are perceptually attenuated. The present experiments determined whether predictive mechanisms always generate attenuation, or instead can enhance perception - as typically observed in sensory cognition domains outside of action. We manipulated probabilistic expectations in a paradigm often used to demonstrate tactile attenuation. Participants produced actions and subsequently rated the intensity of forces on a passive finger. Experiment 1 confirmed previous findings that action outcomes are perceived less intensely than passive stimulation, but demonstrated more intense perception when active finger stimulation was removed. Experiments 2 and 3 manipulated prediction explicitly and found that expected touch during action is perceived more intensely than unexpected touch. Computational modelling suggested that expectations increase the gain afforded to expected tactile signals. These findings challenge a central tenet of prominent motor control theories and demonstrate that sensorimotor predictions do not exhibit a qualitatively distinct influence on tactile perception. Statement of RelevancePerception of expected action outcomes is thought to be attenuated. Such a mechanism may be adaptive because surprising inputs are more useful - e.g., signalling the need to take new courses of action - and is thought to explain why we cannot tickle ourselves and unusual aspects of action and awareness in clinical populations. However, theories outside of action purport that predicted events are perceptually facilitated, allowing us to generate largely accurate representations of our noisy sensory world. We do not know whether action predictions really alter perception differently from other predictions because different manipulations have been performed. Here we perform similar manipulations and demonstrate that action predictions can enhance, rather than attenuate, touch. We thereby demonstrate that action predictions may not have a qualitatively distinct influence on perception, such that we must re-examine theories concerning how predictions influence perception across domains and clinical theories based upon their assumptions.

neuroscience↗