Enhancing Visual Discrimination Task: Optimized Mouse Motivation in the Touchscreen Paradigm

Mouse models are essential for understanding gene function, environmental interaction, and brain structure and function. This is reinforced by the ability of mice to perform complex behavioral tasks. Still, their cognitive assessments often rely on aversive paradigms, such as fear conditioning and the Morris water maze. A promising alternative is the automated touchscreen platform, which enables cognitive tests comparable to those used in humans, such as the Cambridge Neuropsychological Test Automated Battery (CANTAB). This approach enhances standardization and reduces stress by employing appetitive reinforcement. Although widely used in non-human primates, touchscreen testing remains underutilized in rodents despite its potential for cross-species cognitive research. Motivation is key to successful touchscreen tasks, often achieved through water restriction, which mice tolerate well. However, water restriction is a stressful condition, combining negative and positive reinforcement. Here, we propose an alternative that uses citric acid (CA) water to avoid classical food privation in the touchscreen paradigm to mitigate mice's stress. By creating a strong contrast with the reward, we increase the reward's positive valence. We used the touchscreen visual discrimination task to assess the effectiveness of CA water in enhancing motivation. Our results show that administering CA water on training days while allowing access to plain water on weekends reduces the learning phase duration without causing significant weight loss in wild-type C57BL/6J mice. In addition, we observed a strong commitment to performing the pattern dissociation task. This approach offers a welfare-friendly alternative for maintaining motivation in touchscreen-based cognitive tasks while minimizing stress. © 2025 Wiley Periodicals LLC. Basic Protocol: Pattern dissociation paradigm using sour water.