Exaggerated Color Perception in a Patient with Visual Form Agnosia

Abstract

Previous studies on visual form agnosic patients have shown that their color perception is relatively preserved when monochromatic figures are used. However, it is unclear whether their color perception remains normal when figures are composed of two parts in different colors. The results showed that patient X.F. had difficulty in naming both colors when the two colors were placed next to each other, and in discriminating the two-color figure from the figure presented in its larger color. In contrast, X.F. could name the two colors when they were physically separated. These data suggest that X.F. manifests exaggerated color perception, producing a color filling-in effect that may be mediated by her spared early visual area.

Keywords:

• Visual form agnosia
• Color
• Filling-in effect
• Surface
• Contour

Acknowledgments

This research was supported by a grant from the Foundation for the Author of National Excellent Doctoral Dissertation of China (J. Yang, 200207). We thank our patient X.F. and her husband for their willing cooperation. We thank the NCI Fellows' Editorial Board at the National Institute of Health in the USA for their editorial assistance.