Fast neural learning in dogs: A multimodal sensory fMRI study

Ashley Prichard,Raveena Chhibber,Kate Athanassiades,Gregory S Berns,Mark Spivak

doi:10.1038/s41598-018-32990-2

Abstract

Dogs may follow their nose, but they learn associations to many types of sensory stimuli. Are some modalities learned better than others? We used awake fMRI in 19 dogs over a series of three experiments to measure reward-related learning of visual, olfactory, and verbal stimuli. Neurobiological learning curves were generated for individual dogs by measuring activation over time within three regions of interest: the caudate nucleus, amygdala, and parietotemporal cortex. The learning curves showed that dogs formed stimulus-reward associations in as little as 22 trials. Consistent with neuroimaging studies of associative learning, the caudate showed a main effect for reward-related stimuli, but not a significant interaction with modality. However, there were significant differences in the time courses, suggesting that although multiple modalities are represented in the caudate, the rates of acquisition and habituation are modality-dependent and are potentially gated by their salience in the amygdala. Visual and olfactory modalities resulted in the fastest learning, while verbal stimuli were least effective, suggesting that verbal commands may be the least efficient way to train dogs.

Highlights

It is well known that dogs have keen sensory abilities, but are some modalities learned better than others? For example, a dog’s behavior is popularly considered to be driven by their noses[1]
We demonstrated the use of functional magnetic resonance imaging (fMRI) in dogs to compare associative reward-learning in the brain across visual, olfactory, and verbal modalities
Consistent with reward learning in neuroimaging studies, the caudate showed main effects for reward-related stimuli but not a significant interaction with modality

Summary

Introduction

It is well known that dogs have keen sensory abilities, but are some modalities learned better than others? For example, a dog’s behavior is popularly considered to be driven by their noses[1]. Dog-fMRI studies demonstrated the replicability and reliability of caudate activation in response to hand signals predictive of food reward[15]. Later studies extended these results and showed that caudate and amygdala activation were correlated with specific aspects of a dog’s temperament and could even be used as part of a biometric predictor for suitability as a service-dog[16]. If dogs formed modality-independent associations between the conditioned stimuli and reward, activity in the caudate nucleus should increase over time in response to the conditioned reward stimulus relative to the control stimulus, regardless of the modality. Process learning associations in one stimulus modality over another, there will be a difference in the neural rate of learning between the three modalities

Methods

Results

Conclusion