Grasping without sight: insights from the congenitally blind
Loading...
Date
2014
Authors
Stone, Kayla D.
Gonzalez, Claudia L. R.
Journal Title
Journal ISSN
Volume Title
Publisher
Public Library of Science
Abstract
We reach for and grasp different sized objects numerous times per day. Most of these movements are visually-guided, but
some are guided by the sense of touch (i.e. haptically-guided), such as reaching for your keys in a bag, or for an object in a
dark room. A marked right-hand preference has been reported during visually-guided grasping, particularly for small
objects. However, little is known about hand preference for haptically-guided grasping. Recently, a study has shown a
reduction in right-hand use in blindfolded individuals, and an absence of hand preference if grasping was preceded by a
short haptic experience. These results suggest that vision plays a major role in hand preference for grasping. If this were the
case, then one might expect congenitally blind (CB) individuals, who have never had a visual experience, to exhibit no hand
preference. Two novel findings emerge from the current study: first, the results showed that contrary to our expectation, CB
individuals used their right hand during haptically-guided grasping to the same extent as visually-unimpaired (VU)
individuals did during visually-guided grasping. And second, object size affected hand use in an opposite manner for
haptically- versus visually-guided grasping. Big objects were more often picked up with the right hand during hapticallyguided,
but less often during visually-guided grasping. This result highlights the different demands that object features
pose on the two sensory systems. Overall the results demonstrate that hand preference for grasping is independent of
visual experience, and they suggest a left-hemisphere specialization for the control of grasping that goes beyond sensory
modality
Description
Sherpa Romeo green journal: open access
Keywords
Grasping , Haptically-guided grasping , Visually-guided grasping , Hand preference , Right hand , Congenitally blind
Citation
Stone, K. D., & Gonzalez, C. L. R. (2014). Grasping without sight: insights from the congenitally blind. PLoS ONE, 9(10): e110175. doi:10.1371/journal/pone.0110175