Label-based expectations affect incentive contrast effects in bumblebees

Area of Science:

• Behavioral Ecology
• Neuroethology
• Animal Cognition

Background:

• Classic decision-making models assume absolute value assessment.
• Research shows rewards are often evaluated relative to experience (incentive contrast).
• Label-based expectations influence value perception in humans and rodents, but rarely tested in non-model systems.

Purpose of the Study:

• To investigate label-based expectations and incentive contrast in bumblebees.
• To determine if contrast effects are influenced by associated stimuli, not just reward history.
• To explore the generalization of expectations to novel stimuli in bumblebees.

Main Methods:

• Manipulated bumblebees' expectations of floral reward quality before reducing it.
• Introduced novel stimuli paired with lower-quality rewards to assess acceptance speed.
• Tested bees along a stimulus gradient to examine expectation generalization.

Main Results:

• Incentive contrast effects were observed in bumblebees when rewards were lowered.
• Bees accepted lower-quality rewards faster when paired with a novel stimulus, indicating label-based influence.
• Expectations generalized to stimuli similar to those previously experienced.

Conclusions:

• Bumblebee reward evaluation is influenced by learned expectations associated with stimuli, not just absolute reward value.
• Reference-dependent evaluations and stimulus-associated expectations play a significant role in bumblebee foraging decisions.
• These findings have implications for understanding floral evolution and plant community dynamics.