Attention, awareness and flexibility in honeybees: divergent effects of distraction on delay versus trace reversal learning

The question of whether awareness is required for trace but not for delay conditioning has recently been explored in the honeybee, a species renowned for its cognitive abilities. Distractors impair trace but not delay absolute olfactory conditioning, suggesting that bees, like humans, rely on awareness of the conditioned stimulus-unconditioned stimulus contingency during trace learning. Here, we extend this approach to reversal learning, which requires learning an initial discrimination (A+ B-) and subsequently learning the reversed contingencies (A-B+). Bees mastered olfactory reversal learning under both delay and trace protocols but acquisition was slower and less robust under trace than under delay conditioning. Introducing a visual distractor during the reversal phase impaired performance in distinct ways. Delay-conditioned bees increased responsiveness, adopting an A+B+ response profile, whereas trace-conditioned bees decreased responsiveness, adopting an A⁻B⁻ profile. To our knowledge, this is the first study in any animal species investigating reversal learning under a trace-conditioning regime, and the first assessing distractor effects in this paradigm. The contrasting outcomes indicate that the distractor disrupted attentional reallocation in both protocols, but additionally interfered with awareness in trace learning. These findings provide evidence that bees engage awareness-like processes during trace reversal learning, highlighting cognitive processing in an insect.