A cross-species judgement bias task: integrating active trial initiation into a spatial Go/No-go task

Area of Science:

• Animal Behavior
• Cognitive Science
• Comparative Psychology

Background:

• Judgement bias tasks assess animal emotional valence but often are time-consuming and lack validity.
• Existing methods present challenges for cross-species application.

Purpose of the Study:

• To develop an improved, efficient, and valid spatial Go/No-go task for assessing judgement bias across different animal species.
• To establish a practical protocol for comparative studies on animal emotional valence.

Main Methods:

• Horses, rats, and mice were trained on a spatial Go/No-go task involving reward and non-reward cues.
• Ambiguous cue locations were introduced to measure judgement bias using the Go:No-go response ratio.

Main Results:

• Animals across all species rapidly learned the Go/No-go discrimination and initiated trials at a high rate.
• Subjects demonstrated a graded response to ambiguous cues, reliably discriminating them from reference cues.
• No evidence of learning regarding the outcomes of ambiguous trials was observed.

Conclusions:

• The novel spatial Go/No-go task is efficient and valid for assessing judgement bias in animals.
• This protocol offers a practical and adaptable tool for comparative emotional valence studies in diverse species.