On the Matching of Seen and Felt Shape by Newly Sighted Subjects

Abstract

How do we recognize identities between seen shapes and felt ones? Is this due to associative learning, or intrinsic connections these sensory modalities? We can address this question by testing the capacities of newly sighted subjects to match seen and felt shapes, but only if the subjects can see the objects well enough to form adequate visual representations of their shapes. In light of this, a recent study by R. Held and colleagues fails to demonstrate that their newly sighted subjects' inability to match seen and felt shape was due to a lack of intermodal connections rather than a purely visual deficit, as the subjects may not have been able visually to represent 3D shape in the perspective-invariant manner required for intermodal matching. However, the study could be modified in any of several ways to help avoid this problem.

Commentary: “Multimodal Theories of Recognition and Their Relation to Molyneux's Question”

“…Altieri is also correct in endorsing criticisms I have raised (Schwenkler, 2012 , 2013 ; Connolly, 2013 ) against the resolution of Molyneux's question attempted by Held et al ( 2011 ). In this study, newly sighted individuals could match seen objects with seen objects and felt with felt, but could not match seen objects with felt ones, leading the authors to conclude that “the answer to Molyneux's question is likely negative,” as any innate link between vision and touch “is insufficient for reconciling the identity of the separate sensory representations” (Held et al, 2011 ).…”

Molyneux’s Question in Berkeley’s Theory of Vision

“…But even after this pain period (which would count as an adaptation to visual stimuli, thus invalidating the patient as an optimal candidate for the experiment), it is still debatable whether her visual faculties are sufficient for a robust identification of shape or distance. To the best of our current empirical evidence, the best cases we have to test Molyneux-type questions have been not completely blind from the beginning, but blinded at a young age; some have even been able to identify the direction of sources of light (which would imply using visual cues and mapping things in an egocentric space); and lastly, they have had some period of time to gain familiarity not only with visual experience, but with some of the tests they were presented (Cheselden 1727;Connolly 2013;Gallagher 2005;Held et al, 2011;Huber et al, 2015;Meltzoff, and Borton 1979;Sacks 1995;Schwenkler 2012).…”

Obstacles to Testing Molyneux’s Question Empirically

“…(2011) being prominent recent attempts. Schwenkler (2012 , 2013 ) has argued that these studies do not adequately address Molyneux’s question because the participants “could not form the requisite visual representations of those shapes in the first place” (2013, p. 92). Held and colleagues did demonstrate that the participants had visual representations sufficient for performing visual matching, but Schwenkler argues that these representations could have been based on viewpoint-dependent or low-level features, such as number of lines, and proposes two ways to fix this problem.…”