The psychophysics of affordance perception: Stevens' power law scaling of perceived maximum forward reachability with an object.

The literatures on affordance perception and psychophysics are seminal in the basic study of perception and action. Nevertheless, the application of classic psychophysical methodologies/analysis to the study of affordance perception remains unexplored. In four experiments, we investigated the Stevens' power law scaling of affordance perception. Participants reported maximum forward reaching ability with a series of rods (both seated and standing) for themselves and another person (confederate). Participants also reported a property of the rod set that has been explored in previous psychophysical experiments and changes in equal measure with forward reach-with-ability (length). In all, we found that affordance perception reports (ß = .32) were an underaccelerated function of actual changes in reaching ability compared with relatively less accelerated length reports (ß = .73). Affordance perception scaled with stimulus magnitude more similarly to brightness perception than length perception. Furthermore, affordance perception reports scaled similarly regardless of the actor (self and other), task context (seated and standing), or idiosyncrasies of the measurement procedure (controlling for distance compression effects), while length perception reports were sensitive to location/distance compression effects. We offer empirical and theoretical considerations, along with pathways for future research.

Therapeutic Efficacy of Yoga for Common Primary Care Conditions.

INTRODUCTION: Yoga is a popular form of exercise that uses body postures, meditation, and breathing techniques and has been shown to have many health benefits. OBJECTIVE/METHODS: Our goal for this review is to orient health professionals to the evidence-based uses of yoga most relevant to primary care. We conducted a PubMed search that included meta-analyses, reviews, systematic reviews, and randomized controlled trials. RESULTS: Results were limited to English language and publication between 2010 and 2020. Yoga was found to help decrease hypertension, relieve back pain, promote overall well-being, and improve mental health. CONCLUSIONS: Yoga is a relatively safe and effective option for patients interested in therapeutic lifestyle change to promote well-being and to help manage hypertension, back pain, and overall mental health.