Biology subjects

Chang, A. Y.-C.

Publications and source records attributed to Chang, A. Y.-C..

4 recordsLinked to original sources

bioRxiv2025

Bayesian Integration in Sense of Agency: Understanding Self-attribution and Individual Differences

This study developed a Bayesian integration model to explore individual differences in the sense of agency, particularly when multiple sensory cues influence action perception. Behavioral results showed that individuals consistently integrate sensory cues in agency judgments, though cue weighting varies significantly across individuals. The estimated parameters of our model successfully captured these differences, reflecting individual sensitivities and criteria for agency. Higher sensitivity to sensory inputs was associated with lower variance in the likelihood distribution under the assumption of control. Our model provides critical insights into the mechanisms of the sense of agency and its variability, highlighting the models potential for understanding both typical and disordered agency experiences.

neuroscience↗

bioRxiv2024

Reconcile sensory attenuation and enhancement: The temporal dynamics of self-generated sensory feedback

Self-generated touches are often perceived as weaker than externally generated ones, a phenomenon known as sensory attenuation. However, recent studies have challenged this view by providing evidences that actions could also enhance predicted touch. To investigate this paradox, we examined the temporal dynamics of perceptual processing using steady-state somatosensory evoked potentials (SSSEP) and sliding time window analysis. Results showed that SSSEP in the very early window was smaller in the no-delay and active conditions compared to the delayed and passive condition, respectively, consistent with sensory attenuation. However, this attenuation soon disappeared and reversed in the later windows and onward, indicating an early attenuation followed by a later enhancement. This study resolves the paradox of sensory attenuation and enhancement in self-generated sensory signals by demonstrating that these processes occur at different phases of sensory processing. The findings reveal a sophisticated dynamic balance in sensory processing, facilitating optimal interaction with the environment.

neuroscience↗

bioRxiv2024

The sense of agency from active causal inference

This study investigates the active component of the sense of agency (SoA), positing that SoA is fundamentally an outcome of active causal inference regarding ones own actions and their impact on the environment. Participants controlled visual objects via a computer mouse, with tasks designed to test their ability to judge control or detect controlled objects under varying noise conditions. Our findings reveal that participants formed high-level, low-dimensional action plans that were idiosyncratic across but consistent within individuals to infer their degree of control. Employing transformer-LSTM-based autoencoders, we captured these action plans and demonstrated that the geometrical and dynamical properties of these action plans could predict behavioural profiles in the tasks with remarkable accuracy. This suggests that participants sense of control is shaped by actively altering action plans, viewed as generating causal evidence through intervention. Further, participants proactively expanded the diversity of their action plans, facilitating the exploration of available action plan options while accumulating causal evidence for the inference process. Contrarily, patients with schizophrenia exhibited reduced action plan diversity, suggesting impaired active control inference and detection of self-relevant cues. These findings offer a more comprehensive understanding of the sense of agency, deeply rooted in the process of active causal inference.

neuroscience↗

bioRxiv2017

Neurophysiological signatures of duration and rhythm prediction across sensory modalities

Effective behaviour and cognition requires the ability to make predictions about the temporal properties of events, such as duration. It is well known that violations of temporal structure within sequences of stimuli lead to neurophysiological effects known as the (temporal) mismatch negativity (TMMN). However, previous studies investigating this phenomenon have typically presented successive stimulus intervals (i.e., durations) within a rhythmic structure, conflating the contributions of rhythmic temporal processing with those specific to duration. In a novel behavioural paradigm which extends the classic temporal oddball design, we examined the neurophysiological correlates of prediction violation under both rhythmically (isochronous) and arrhythmically (anisochronous) presented durations, in visual and auditory modalities. Using event-related potential (ERP), multivariate pattern analysis (MVPA), and temporal generalisation analysis (TGA) analyses, we found evidence for common, and distinct neurophysiological responses related to duration predictions and their violation, across isochronous and anisochronous conditions. Further, using TGA we could directly compare processes underlying duration prediction violation across different modalities, despite differences in processing latency of audition and vision. We discovered a common set of neurophysiological responses that are elicited whenever a duration prediction is violated, regardless of presentation modality, indicating the existence of a supramodal duration prediction mechanism. Altogether, our data show that the human brain encodes predictions specifically about duration, in addition to those from rhythmic structure, and that the neural underpinnings of these predictions generalize across modalities. These findings support the idea that time perception is based on similar principles of inference as characterize predictive processing theories of perception.

neuroscience↗