The basal ganglia within a cognitive system in birds and mammals.

The primate basal ganglia are fundamental to Ackermann et al.'s proposal. However, primates and rodents are models for human cognitive functions involving basal ganglia circuits, and links between striatal function and vocal communication come from songbirds. We suggest that the proposal is better integrated in cognitive and/or motor theories on spoken language origins and with more analogous nonhuman animal models.