Brain–Behavior Differences in Premodern and Modern Lineages of … paper comparing brain structure across 85 domestic dogs found clear differences between modern breed lineages and premodern dogs, linking those differences to trainability and fear-related behavior.

The study, credited to Barton et al., reports that modern breeds display widespread expansion of neocortex while premodern dogs show relatively larger subcortical regions, notably the amygdala. This discrepancy highlights how selective breeding has produced distinct structural brain differences across dog breeds, with networks related to vision, olfaction, reward, social cognition, and fear systematically varying according to the behaviors for which the dogs were bred—be it herding, hunting, guarding, or companionship. Those structural differences corresponded with behavioral measures: cortical size predicted variation in trainability and amygdala measurements predicted fear-related scores.

The sample included modern breed dogs and premodern groups described as primitive or ancient breeds, village dogs, and New Guinea Singing Dogs. Barton et al. mapped structural features across those lineages and identified consistent patterns in which higher-order cortical regions were proportionally larger in modern breeds, while subcortical areas associated with emotional reactivity were proportionally larger in the premodern animals. This anatomical divergence can be traced back to intense artificial selection for appearance and function in modern breeds over the past 200 years, which has targeted higher-order brain regions like the neocortex.

By tying anatomy to behavior, the authors linked two specific brain measures to different aspects of canine temperament: cortical measurements to trainability and amygdala measurements to fear-related behavior. Harvard researcher finds canine brains vary based on breed. Dogs with different brain structures tend to learn best when training is adapted to their strongest sensory and cognitive systems, such as using more visual and olfactory cues for dogs with enhanced visual or scent-processing regions. Those associations were reported across the full set of 85 animals, indicating systematic brain–behavior relationships between the lineage groups rather than isolated findings in single breeds.

The paper appears as part of work made available through research communications and project pages that document ongoing comparisons between modern and premodern dogs; additional project materials and context are available on the study’s project page at the Evolutionary Neuroscience Lab site.

Because the analysis spans dogs that have experienced different histories of human-directed breeding, the authors frame the results as informative about how recent selective pressures on modern breeds relate to neural systems that support learning and emotional reactivity. The study therefore provides a neuroanatomical basis for breed-linked differences in behavior while underscoring that different lineages retain distinct structural profiles.

Publication in a peer-reviewed context makes the imaging-derived comparisons available to other researchers examining domestication, selection, and canine cognition. Why dogs are not wolves – humans changed the dog’s brain. Barton et al. present the structural and behavioral correlations as a resource for understanding variation across domestic dog lineages.

Where these patterns lead next, the authors suggest, will depend on further work linking anatomy, genetics, and lived experience across more dogs and more diverse populations. For now, the study reports a clear anatomical split between modern and premodern lineages in a sample of 85 animals and ties those differences to measures of trainability and fear-related behavior. Fast neural learning in dogs: A multimodal sensory fMRI study – Nature.

Source

Original reporting: view the original article.