Coffee time: Low caffeine dose promotes attention and focus in zebrafish

• Published in: Learning & behavior 2019-09, Vol.47 (3), p.227-233
• Main Authors: Ruiz-Oliveira, Julia, Silva, Priscila Fernandes, Luchiari, Ana Carolina
• Format: Article
• Language: English
• Subjects: Attention; Behavioral Science and Psychology; Caffeine; Coffee; Conditioning; Danio rerio; Latency; Neurosciences; Psychology; Reinforcement; Visual discrimination; Visual stimuli
• ISSN: 1543-4494; 1543-4508
• DOI: 10.3758/s13420-018-0369-3

In this study we investigated the ability of zebrafish to discriminate visual signs and associate them with a reward in an associative-learning protocol including distractors. Moreover, we studied the effects of caffeine on animal performance in the task. After being trained to associate a specific image pattern with a reward (food) in the presence of other, distractor images, the fish were challenged to locate the exact cue associated with the reward. The distractors were same-colored pattern images similar to the target. Both the target and distractors were continually moved around the tank. Fish were exposed to three caffeine concentrations for 14 days: 0 mg/L (control, n = 12), 10 mg/L ( n = 14), and 50 mg/L ( n = 14). Zebrafish spent most of the time close to the target (where the reward was offered) under the effects of 0 and 10 mg/L caffeine, and the shortest latency to reach the target was observed for the 10-mg/L caffeine group. Both caffeine treatments (10 and 50 mg/L) increased the average speed and distance traveled when compared to the control group. This study confirms previous results showing that zebrafish demonstrate conditioned learning ability; however, low-dose caffeine exposure seems to favor visual cue discrimination and to increase zebrafish performance in a multicue discrimination task, in which primarily focus and attention are required in order to obtain the reward.