Background & Problem Statement

Under conditions of sensory uncertainty, the brain's perceptual system increasingly relies on prior expectations to make inferences. However, there is a significant gap in the literature regarding whether internal physiological signals, specifically cardiovascular interoception, directly modulate visual perception bias and criterion shifts during absolute sensory ambiguity.



Objective

The primary objective of this research is to determine the modulatory role of objective interoceptive accuracy (IAc) in the integration of prior expectations and sensory evidence (likelihoods) during visual decision-making under uncertainty.



Methodology

This applied research utilizes a quantitative, within-subject experimental design involving at least 60 healthy student volunteers aged 18 to 35. Following the completion of the MAIA-2 and DASS-21 questionnaires, participants will engage in two psychophysical tasks within the PsychoPy environment: the Schandry mental heartbeat tracking task (with simultaneous objective pulse recording via an Arduino-connected optical sensor) and a Gabor patch orientation discrimination task under varying Gaussian noise levels.



Procedure & Ethical Considerations

As a minimally invasive study, explicit informed consent will be obtained after providing initial instructions. Both behavioral and physiological data will be securely collected and subsequently analyzed using a Logistic Generalized Linear Mixed Model (GLMM) alongside Signal Detection Theory (SDT).