Davida's deficits: weak encoding of impoverished stimuli or faulty egocentric representation?

Abstract

Vannuscorps and colleagues present the fascinating case of Davida, a young person who makes systematic errors in judgments related to orientations of sharp or high-contrast visual stimuli. In this commentary, we discuss the findings in the context of observations from mid-level ventral visual stream physiology. We propose two additional interpretations for the specificity of the behavioural deficits: the observed impairments in orientation judgments may be consistent with a system that is not able to unambiguously represent certain impoverished stimuli, or with a system that is not able to translate visual input into head- or body-centered coordinates. Davida's case offers a unique glimpse into the complex cascade of transformations that enable accurate orientation judgments, and sparks curiosity about which mechanistic disruptions can produce such specific unstable percepts.