The ability of lambs to form expectations and the emotional consequences of a discrepancy from their expectations.

Abstract in brief

• Lambs can form expectations about food rewards, and their emotional and physiological responses are affected when those expectations are not met, such as in reward decreases or extinction scenarios.
• When lambs experience negative shifts (less reward), they show increased activity, less task efficiency, and changes in heart activity, especially if they previously received larger rewards, indicating emotional discomfort.
• The study suggests that lambs’ reactions to reward changes are complex and resemble appraisal processes seen in humans, with physical stress markers like cortisol not always directly aligning with behavioral responses.