Lesions of lateral habenula attenuate win-stay but not lose-shift responses in a competitive choice task.

Multiple neural systems contribute to choice adaptation following reinforcement. Recent evidence suggests that the lateral habenula (LHb) plays a key role in such adaptations, particularly when reinforcements are worse than expected. Here, we investigated the effects of bilateral LHb lesions on responding in a binary choice task with no discriminatory cues. LHb lesions in rats decreased win-stay responses but surprisingly left lose-shift responses intact. This same dissociated effect was also observed after systemic administration of d-amphetamine in a separate cohort of animals. These results suggest that at least some behavioural responses triggered by reward omission do not depend on an intact LHb.