Colour agnosia impairs the recognition of natural but not of non-natural scenes

Abstract

Scene recognition can be enhanced by appropriate colour information, yet the level of visual processing at which colour exerts its effects is still unclear. It has been suggested that colour supports low-level sensory processing, while others have claimed that colour information aids semantic categorization and recognition of objects and scenes. We investigated the effect of colour on scene recognition in a case of colour agnosia, M.A.H. In a scene identification task, participants had to name images of natural or non-natural scenes in six different formats. Irrespective of scene format, M.A.H. was much slower on the natural than on the non-natural scenes. As expected, neither M.A.H. nor control participants showed any difference in performance for the non-natural scenes. However, for the natural scenes, appropriate colour facilitated scene recognition in control participants (i.e., shorter reaction times), whereas M.A.H.'s performance did not differ across formats. Our data thus support the hypothesis that the effect of colour occurs at the level of learned associations.

Tanja Nijboer was supported by NWO Grant 051.02.080 of the Cognition Program of the Netherlands Organization for Scientific Research (NWO). Maarten van der Smagt was supported by the NWO Innovational Research Grant 451.02.094 (VENI scheme) of the Netherlands Organization for Scientific Research (NWO). We would like to thank M.A.H for his generous participation. We thank Jennifer Steeves and colleagues for making their elaborate stimulus set available to us. Also, we thank Ryota Kanai for useful discussion of many aspects of this article.

Notes

¹ Note, however, that Biederman and Ju (1988) also showed that using a mask eliminated this facilitatory effect of colour.