Brain-Behavior Differences in Premodern and Modern Lineages of Domestic Dogs

Area of Science:

• Comparative psychology
• Neuroscience
• Animal behavior

Background:

• Dog domestication is the first example of animal domestication, yet the specific brain and behavior changes are debated.
• Modern breed dogs show significant changes due to intense artificial selection over the last 200 years.
• Premodern dogs retain more ancestral traits, offering a comparison to understand recent domestication effects.

Purpose of the Study:

• To investigate brain structure differences between modern and premodern dogs.
• To correlate brain morphology with behavioral traits like trainability and fear.
• To re-evaluate the impact of domestication on canine brain evolution.

Main Methods:

• Voxel-based morphometry analysis of structural MRI scans.
• Comparison of 72 modern breed dogs with 13 premodern dogs.
• Statistical correlation between brain region volumes and behavioral scores.

Main Results:

• Modern breed dogs exhibited expanded neocortex and reduced amygdala volumes compared to premodern dogs.
• Neocortical measurements correlated with trainability, while amygdala size predicted fear scores.
• Findings challenge the notion that domestication uniformly reduces brain size and cognitive function.

Conclusions:

• Recent artificial selection has specifically targeted higher-order brain regions in modern dogs.
• These brain changes likely facilitate behavioral flexibility and human-canine cooperation.
• Domestication's impact on brain evolution is more nuanced than previously thought.