Vision Sciences Society Abstract

We have submitted an abstract for the Vision Sciences Society Meeting in Sarasota, Florida this May. The abstract highlights the colour-memory patient, QP, that Loni has been investigating.

Colour-Specific Deficits in Implicit Colour Working Memory: A Visuomotor Case Study
Loni Rhode1,2, Lee A Baugh1,2, Pauline M Pearson3, Lorna S Jakobson2, Jonathan J Marotta1,2
1Neuropsychology of Vision Perception and Action Lab
2Department of Psychology, University of Manitoba
3Department of Psychology, Univeristy of Winnipeg

Previous research has demonstrated that grasping can be altered through implicitly established colour-size associations (Haffenden & Goodale, 2000). After training with “large” red and “small” blue blocks, subjects open their hands wider when grasping “medium” blue probe blocks than when grasping identically sized red blocks. We examined whether QP, an individual who has a selective deficit in explicit colour working memory, demonstrates an influence of colour-size associations on grip aperture. Results from 13 right-handed control participants revealed that grip aperture was significantly wider for the blue probe block than for the red probe block (difference of 2.46 mm, p<.05). As with the controls, QP also increases her grip aperture for the blue block (difference 3.26 mm). To explore whether colour-size associations generalize within a colour category, light blue and light red probe blocks that were not part of the training phase were added to the test phase. In controls, differences between the light blue and light red probe blocks were not observed. In contrast, QP shows a difference for light red compared to light blue probe block (2.66 mm). These visuomotor findings suggest that QP’s colour memory deficits also affect her implicit colour memory, and that the influence of implicit color memory on visually guided grasping normally does not generalize within colour categories. Consistent with QP’s difficulty in recalling specific shades of a colour, her colour-size associations do not exhibit normal specificity.