IS PATTERN VISION IN INSECTS MEDIATED BY CORTICAL PROCESSING

IT is known that bees, like humans, can learn the orientation of a striped pattern, and recognize this orientation in other simple patterns that they have never previously encountered1,2. How is orientation analysed by the insect visual system? In the light of what is known about animal vision, there are two obvious possibilities. First, orientation could be determined purely in terms of the directional movement signals that the pattern generates as the bee approaches it or flies past it3,4. Such a scheme would fit in well with the common supposition that much of insect vision relies solely on motion cues4,5. An alternative view, not considered for insect vision so far, would be that specific features of the pattern, such as bars or edges, are extracted and their orientation analysed as in the mammalian cortex. Our findings argue strongly against the first and for the second possibility. They suggest that similar principles underlie the analysis of pattern orientation in insects and higher vertebrates