In the text, the word "responded" is a link to this study: https://www.sciencedirect.com/science/article/pii/S0960982211005446 https://www.sciencedirect.com/sc

In the text, the word "responded" is a link to this study: https://www.sciencedirect.com/science/article/pii/S0960982211005446 https://www.sciencedirect.com/science/article/pii/S096098221... > A pessimistic cognitive bias is manifested in an increased tendency of subjects to classify stimuli as likely to predict punishment (or a reward of less value). We were able to use the same approach to test for cognitive biases in honeybees because bees are capable of associative learning and can base judgments about novel stimuli on previous experiences [24, 25, 26, 27]. Using an olfactory learning protocol for conditioned proboscis extension, we trained honeybees to extend their mouthparts to a two-component odor mixture (CS+) predicting a reward (e.g., 1.00 or 2.00 M sucrose) and to withhold their mouthparts from another mixture (CS−) predicting either punishment or a less valuable reward (e.g., 0.01 M quinine solution or 0.3 M sucrose; Figure 1).