Do spatial features appear the same whether they are perceived through vision or touch? This question is at stake in the puzzle that William Molyneux posed to John Locke, concerning whether a man born blind whose sight was restored would be able immediately to identify the shapes of the things he saw. A recent study purports to answer the question negatively, but I argue here that the subjects of the study likely could not see well enough for the result to (...) have been meaningful. I then propose a way to improve the study, by including cues from object motion. (shrink)

PurposeIf an individual has been blind since birth due to a treatable eye condition, ocular treatment is urgent. Even a brief period of visual deprivation can alter the development of the visual system. The goal of our structured scoping review was to understand how we might better support children with delayed access to ocular treatment for blinding conditions.MethodWe searched MEDLINE, Embase and Global Health for peer-reviewed publications that described the impact of early and extended bilateral visual deprivation.ResultsOf 551 reports independently (...) screened by two authors, 42 studies met our inclusion criteria. Synthesizing extracted data revealed several trends. The data suggests persistent deficits in visual acuity, contrast sensitivity, global motion, and visual-motor integration, and suspected concerns for understanding complex objects and faces. There is evidence for resilience in color perception, understanding of simple shapes, discriminating between a face and non-face, and the perception of biological motion. There is currently insufficient data about specific habilitation strategies to update low vision services, but there are several insights to guide future research in this domain.ConclusionThis summary will help guide the research and services provision to help children learn to see after early and extended blindness. (shrink)

Molyneux’s question famously asks about whether a newly sighted subject might immediately recognize, by sight alone, shapes that were already familiar to her from a tactile point of view. This paper addresses three crucial points concerning this puzzle. First, the presence of two different questions: the classic one concerning visual recognition and another one concerning vision-for-action. Second, the explicit distinction, reported in the literature, between ocular and cortical blindness. Third, the importance of making reference to our best neuroscientific account on (...) vision, ‘the two visual systems model’, in order to better address Molyneux’s problem. Then, by offering a new, deeper analysis of the relation between, and, this paper suggests that the subjects of Molyneux’s two different questions show the same visual impairment as brain-damaged subjects with different lesions of the visual cortex. In particular, the subject of the first question shows the same impairment in visual recognition as a visual agnosic subject, while the subject of the second question shows the same visual impairment in visuomotor processing as an optic ataxic subject. These impairments still hold even if ocular processing is restored. Therefore, I suggest the following. For the first classic question, the required experimental setting cannot be properly reached. By contrast, concerning the second question, based on the interpretation we select, either the answer is negative, or, as with the first question, the experimental setting cannot be properly reached. This proposal constitutes, with the other approaches offered in the literature, a further attempt to tackle the enormous complexity of Molyneux’s puzzle. (shrink)