Measuring Cognitive Judgement Bias in Rats Using the Ambiguous-Cue Interpretation Test

Area of Science:

• Behavioral neuroscience
• Animal cognition
• Operant conditioning

Background:

• Cognitive judgment bias is a key aspect of animal emotional states.
• Measuring this bias in rodents requires validated behavioral paradigms.
• Previous methods may lack the nuance to capture subtle shifts in expectation.

Purpose of the Study:

• To describe and validate a novel active-choice, operant, ambiguous-cue interpretation (ACI) paradigm.
• To establish ACI as a reliable tool for assessing cognitive judgment bias in rats.
• To provide a framework for understanding 'optimism' and 'pessimism' in rodent decision-making.

Main Methods:

• Rats were trained in an operant chamber using distinct tones signaling food reward or foot-shock punishment.
• Ambiguous tones, intermediate in frequency, were introduced after stable discrimination was achieved.
• Lever-press responses to ambiguous cues were recorded to infer expectation bias.

Main Results:

• The ACI paradigm successfully trained rats to discriminate between positive and negative cues.
• Response patterns to ambiguous cues varied, indicating differential expectations of reward or punishment.
• This differential responding serves as a quantifiable measure of cognitive judgment bias.

Conclusions:

• The active-choice, operant, ambiguous-cue interpretation (ACI) paradigm is a viable method for measuring cognitive judgment bias in rats.
• This paradigm offers a sensitive tool to investigate the neurobiological underpinnings of optimism and pessimism.
• ACI advances the study of affective states and decision-making in preclinical models.