Lateralized Functions in the Dog Brain

During the approximately 18-32 thousand years of domestication, dogs and humans have shared a similar social environment. Dog and human vocalizations are thus familiar and relevant to both species, although they belong to evolutionarily distant taxa, as their lineages split approximately 90-100 million years ago. In this first comparative neuroimaging study of a nonprimate and a primate species, we made use of this special combination of shared environment and evolutionary distance. We presented dogs and humans with the same set of vocal and nonvocal stimuli to search for functionally analogous voice-sensitive cortical regions. We demonstrate that voice areas exist in dogs and that they show a similar pattern to anterior temporal voice areas in humans. Our findings also reveal that sensitivity to vocal emotional valence cues engages similarly located nonprimary auditory regions in dogs and humans. Although parallel evolution cannot be excluded, our findings suggest that voice areas may have a more ancient evolutionary origin than previously known. Copyright © 2014 Elsevier Ltd. All rights reserved.

Snakes are among the most common targets of fears and phobias. In visual detection tasks, adults detect their presence more rapidly than the presence of other kinds of visual stimuli. We report evidence that very young children share this attentional bias. In three experiments, preschool children and adults were asked to find a single target picture among an array of eight distractors. Both the children and the adults detected snakes more rapidly than three types of nonthreatening stimuli (flowers, frogs, and caterpillars). These results provide the first evidence of enhanced visual detection of evolutionarily relevant threat stimuli in young children.