Related Experiment Video
Updated: Jan 11, 2026
Assessment of Mouse Judgment Bias through an Olfactory Digging Task
Published on: March 4, 2022
Characterisation of a touchscreen-based task for assessing cognitive judgement bias in mice: a new translational tool
Laura Lopez-Cruz1,2, Benjamin U Phillips3, Lisa M Saksida4,5
1Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge, CB2 3EB, UK. laura.lopez-cruz@open.ac.uk.
Rationale:
A major obstacle in the pre-clinical study of mood-related disorders and novel affective state therapeutic evaluation is the lack of animal models that fully recapitulate human symptomatology.
Objective:
In this study, we developed a touchscreen-based cognitive judgement bias (CJB) task for mice.
Methods:
In the CJB task, animals first learned to discriminate between two visual stimuli displayed on the touchscreen: one associated with a reward (S+) and one associated with a time-out and flashing house light (S-). Once mice learned to respond to the S + and to withhold responding to the S- consistently, a set of four ambiguous stimuli ranging in visual similarity to the S + and S- stimuli were randomly interspersed in the stimulus presentation sequence. Responses to these ambiguous stimuli were interpreted as a greater expectation of positive ('optimistic bias') or negative ('pessimistic bias') outcomes as a function of their similarity to the S + or S- stimuli.
Results:
The acute administration of the SSRIs fluoxetine and citalopram, and the 5HT-2 C receptor antagonist SB 242084, did not produce any effects on CJB task performance. However, the noradrenaline/dopamine reuptake inhibitor, bupropion, increased responses to the ambiguous stimuli consistent with the induction of an 'optimistic bias', and the pro-depressant tetrabenazine yielded the opposite effect.
Conclusion:
This study underscores the capacity of mice to respond to visually ambiguous stimuli in an ambiguity-dependent manner, a phenomenon observed across various species, including humans. Furthermore, it establishes and validates an operant behavioural task to assess CJB in mice delivered using the touchscreen platform, which has significant cross-species translational potential.
