Impaired instrumental choice in crib-biting horses (Equus caballus).

The research explores the cognitive differences between horses displaying an oral stereotypy, known as crib-biting, and non-stereotypic counterparts by testing their learning capabilities through an instrumental choice paradigm. It suggests that stereotypic horses, who have known dysfunction in a specific area of their brain, fail to learn to favour immediate rewards as effectively as non-stereotypic horses.

Understanding Stereotypic Behaviour in Horses

• Oral stereotypy in horses, also known as crib-biting, is a repetitive, compulsive behaviour, often associated with stress or boredom.
• The dorsomedial striatum, a region of the brain, is known to be dysfunctional in horses exhibiting this behaviour. The dysfunction of this area may affect response-outcome learning, an essential aspect of decision-making.

Research Methodology

• The researchers used an instrumental choice paradigm to test the learning capabilities of both stereotypic and non-stereotypic horses. This paradigm is designed to test the subject’s ability to learn to choose one response over another based on the outcomes they produce.
• Over three sessions, the researchers examined how well the horses learned to choose an immediate reward over a delayed one.

Key Results

• The results showed that non-stereotypic horses were able to learn to choose the more immediate reward, indicating normal response-outcome learning.
• On the other hand, stereotypic horses did not learn to do the same, implying that the dysfunction of the dorsomedial striatum indeed has a significant impact on their learning abilities.

Significance and Implications

• The results provide a potential behavioural link to the brain dysregulation observed in horses displaying stereotypic behaviours. More specifically, it emphasizes the role of the dorsomedial striatum in the cognitive dysfunctions associated with stereotypies.
• This research presents a stepping stone for further studies into the neurological and behavioural implications of stereotypic behaviours in horses and potentially other animals.