MULTIPLE FACTORS SHAPE AUDIOVISUAL RAPID RECALIBRATION: EXPERIMENTAL, ENVIRONMENTAL, AND DECISION-RELATED INFLUENCES

The brain exhibits a strong propensity to integrate closely-timed sensory stimuli into a unified percept, a process that is highly malleable and sensitive to temporal discrepancies. As a result of temporal misalignments in multisensory input, the brain engages rapid recalibration mechanisms to preserve appropriate integration across modalities. Although rapid recalibration is commonly observed during audiovisual temporal perception and is known to be impaired in various clinical populations, the factors that influence its emergence have not been fully elucidated. Here, we examine how experimental, environmental, pharmacological, and decision-making factors influence rapid recalibration, using an audiovisual temporal order judgment task in rats. We first show that experimental parameters, including stimulus salience, significantly modulate recalibration effects, with decreased stimulus salience resulting in a larger degree of rapid recalibration. Beyond task parameterization, we demonstrate that environmental factors that worsen hearing acuity exaggerate rapid recalibration in a manner consistent with decreased stimulus salience. Conversely, using pharmacological manipulations throughout the brain or within specific cortical regions, we reveal that shifting the balance of excitation and inhibition towards over-excitation causes a loss of rapid recalibration, suggesting a mechanistic role for neuromodulation in recalibration dynamics. Finally, we examine the contribution of decision-making processes, showing that recalibration is not solely driven by sensory encoding but may also be influenced by changes in evidence accumulation and variability in reaction times. Together these findings expand our understanding of how sensory, neuromodulatory and decision-making factors influence the brain’s ability to rapidly adapt to changing multisensory cues within the environment.