OLFACTORY LEARNING AND BRAIN LESIONS IN THE WOOD ANT (FORMICA RUFA).

Abstract : A technique is described for training ants in a T-maze, using olfactory cues. True olfactory learning occurs and amputation of the antennae prevents the use of olfactory cues. Amputation of one antenna causes a slight falling off in performance, but the ants still perform well above chance level after the operation. After ants have been trained in an olfactory discrimination, the effect of brain lesions on performance is studied. Severing the tracts between both antennal lobes and the alpha lobes of the mushroom bodies causes performance to fall back to chance level. Severing the tracts on only one side of the brain, or lesions placed elsewhere, does not disturb performance. Results are discussed in relation to the involvement of the mushroom bodies and antennal lobes in learning. (Author)