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Abstract Dogs and humans have co-evolved for millennia. This provides an opportunity to examine neural adaptations supporting cross-species communication. Previous canine fMRI studies have identified functional activations in response to human voice perception. However, the specific neural pathways involved in dogs’ ability to process and respond to human language remain unknown. This study takes a data-driven approach to examine the brain connectivity supporting bidirectional communication in a large sample of dogs. We examine white matter pathways linking temporal regions, involved in the perception of communicative signals, and frontal regions, responsible for generating communicative responses. Using cortical regions with known axonal connectivity from tract tracing studies as a foundation, we applied probabilistic tractography to measure connectivity patterns in a diverse cohort of dogs (n = 110, 16 breeds). Our findings reveal that, beyond short-range intra-regional connections, consistent large-scale tracts connect the prefrontal, somatosensory, premotor, motor, and temporal lobes across subjects. Hierarchical clustering analysis revealed distinct structural organization, with sylvian regions strongly connected to motor regions and ectosylvian regions linked to higher-order frontal and prefrontal regions. This organization may suggest that the ectosylvian gyrus plays a key role in integrating auditory input with complex cognitive functions, potentially underlying cross-species communication and language processing in dogs. This study elucidates cortico-cortical communication pathways in dogs and contributes to our understanding of the neural basis of lexical processing in the canine brain.
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A left-lateralized white matter tract associated with communication in domestic dogs
The ability to communicate with conspecifics is an adaptive behavior important for survival and reproduction, particularly in lineages that evolved enlarged brains and complex social behavior. In humans, language is supported by a robust, left-lateralized white matter fiber tract called the arcuate fasciculus, which links Broca’s and Wernicke’s areas, the core neocortical language regions located in the frontal and temporal lobes, respectively1. This tract is also present in chimpanzees, less substantial than in humans and either weakly leftwardly-asymmetric or not asymmetric2. Other mammalian lineages have evolved large brains, complex behavior and social communication in parallel with primates, notably including carnivores. In dogs (Canis familiaris), domestication has almost certainly involved additional selective pressures and environmental factors that have shaped the evolution and development of neural circuits for communication. We report that the dog brain possesses a large, left-lateralized white matter tract that links cortical centers for productive and receptive communication, and that this tract is positively associated with individual variation in receptive vocabulary size.
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- Award ID(s):
- 2238071
- PAR ID:
- 10568087
- Publisher / Repository:
- Current Biology
- Date Published:
- Journal Name:
- Current Biology
- Volume:
- 34
- Issue:
- 21
- ISSN:
- 0960-9822
- Page Range / eLocation ID:
- R1069 to R1070
- Subject(s) / Keyword(s):
- neuroscience canine dog neuroimaging tractography communication ethology
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/2024.09.021
