Temporal stability of Bayesian belief updating in perceptual decision-making.

Bayesian inference suggests that perception is inferred from a weighted integration of prior contextual beliefs with current sensory evidence (likelihood) about the world around us. The perceived precision or uncertainty associated with prior and likelihood information is used to guide perceptual decision-making, such that more weight is placed on the source of information with greater precision. This provides a framework for understanding a spectrum of clinical transdiagnostic symptoms associated with aberrant perception, as well as individual differences in the general population. While behavioral paradigms are commonly used to characterize individual differences in perception as a stable characteristic, measurement reliability in these behavioral tasks is rarely assessed. To remedy this gap, we empirically evaluate the reliability of a perceptual decision-making task that quantifies individual differences in Bayesian belief updating in terms of the relative precision weighting afforded to prior and likelihood information (i.e., sensory weight). We analyzed data from participants (n = 37) who performed this task twice. We found that the precision afforded to prior and likelihood information showed high internal consistency and good test-retest reliability (ICC = 0.73, 95% CI [0.53, 0.85]) when averaged across participants, as well as at the individual level using hierarchical modeling. Our results provide support for the assumption that Bayesian belief updating operates as a stable characteristic in perceptual decision-making. We discuss the utility and applicability of reliable perceptual decision-making paradigms as a measure of individual differences in the general population, as well as a diagnostic tool in psychiatric research.

Bayesian accounts of perceptual decisions in the nonclinical continuum of psychosis: Greater imprecision in both top-down and bottom-up processes.

Neurocomputational accounts of psychosis propose mechanisms for how information is integrated into a predictive model of the world, in attempts to understand the occurrence of altered perceptual experiences. Conflicting Bayesian theories postulate aberrations in either top-down or bottom-up processing. The top-down theory predicts an overreliance on prior beliefs or expectations resulting in aberrant perceptual experiences, whereas the bottom-up theory predicts an overreliance on current sensory information, as aberrant salience is directed towards objectively uninformative stimuli. This study empirically adjudicates between these models. We use a perceptual decision-making task in a neurotypical population with varying degrees of psychotic-like experiences. Bayesian modelling was used to compute individuals' reliance on prior relative to sensory information. Across two datasets (discovery dataset n = 363; independent replication in validation dataset n = 782) we showed that psychotic-like experiences were associated with an overweighting of sensory information relative to prior expectations, which seem to be driven by decreased precision afforded to prior information. However, when prior information was more uncertain, participants with greater psychotic-like experiences encoded sensory information with greater noise. Greater psychotic-like experiences were associated with aberrant precision in the encoding both prior and likelihood information, which we suggest may be related to generally heightened perceptions of task instability. Our study lends empirical support to notions of both weaker bottom-up and weaker (rather than stronger) top-down perceptual processes, as well as aberrancies in belief updating that extend into the non-clinical continuum of psychosis.

Accessible design features and home modifications to improve physical housing accessibility: A mixed-methods survey of occupational therapists.

BACKGROUND: Despite the number of older people and people with disabilities increasing in Australia, it is unclear which housing design features are needed to support physical housing accessibility for people with and without disabilities across the lifespan. OBJECTIVE: This study drew upon the experience of occupational therapists to investigate accessible housing design features and home modifications to support aging in place and discharge from hospital to home. METHODS: A cross-sectional online survey exploring housing design features and home modifications was completed by 144 Australian occupational therapists over six weeks in 2021. Descriptive quantitative and qualitative data analyses were used. RESULTS: For both aging in place and hospital discharge, the most important housing design features included step-free access to the dwelling, large step-free showers, and bathroom and bedroom space on the ground floor. Qualitative findings also highlighted the importance of preparing for home modifications, such as reinforcing bathroom walls to support the post-build installation of grab rails. The most frequently needed modifications were for bathroom features, while structural changes to the dwelling were the most time-intensive modifications, requiring more than six weeks to be completed. CONCLUSIONS: External access to the home and internal access to bedroom and bathroom facilities can support aging in place and hospital discharge and mitigate the need for costly and time-intensive home modifications. While this study was conducted in Australia, the findings have relevance outside of this context, and are important for ensuring equitable accessibility for people with and without disabilities across the lifespan.