DISCRIMINATION OF COMPLEX TEXTURES BY BEES

T. Maddess, M. P. Davey and E. C. Yang

A problem confronted by visual systems is that of discriminating textures. It appears that a recently described class of orientation tuned neurones in the bee brain embody properties of mechanisms used by humans to discriminate complex textures. In particular these mechanisms would permit bees to discriminate a large range of textures by giving bees access to information related to higher order correlations between texture elements. To determine if bees can exploit such textural information we have conducted behavioural experiments employing iso-dipole textures, that statistically speaking, differ from binary noise textures, and each other, only in their third order correlation functions. While these textures are not themselves of any ethological significance their special properties permit us to show that bees can potentially use a very large palette of textures to classify textured objects. In electrophysiological experiments we demonstrate the requisite contrast sign invariance (rectification) of the orientation selective neurones’ responses and discuss other similarities of these neurones’ responses to models accounting for human texture discrimination.