The Vertebrate Strategy for Brain Evolution

In the study of Biologically Inspired Cognitive Architectures (BICA), relatively little attention has been paid to the evolutionary development of cognitive capabilities. There are two successful evolutionary strategies, i.e. resilient and cheap to reproduce individuals vs. more capable individuals that are necessarily expensive to reproduce. The vertebrate family is the prime example of the “evolve more capable individual” strategy. A sequence of increasingly complex and cognitively capable individuals has resulted from the vertebrate strategy. At the heart of the vertebrate strategy is a set of midbrain structures common to all vertebrates. The role of the core structures seems to be preparing the body for different classes of sensory-guided behaviors, while interactions among the core structures insure appropriate switching between behavior classes. More complex vertebrate brains evolved by adding new structures with feedback loops that link the new structure to the core structures and to sensory and motor processing components. A general rule for a new vertebrate structure is that it has to leave the core structures along the central midline of the brain intact, and that it cannot degrade functionality found in brains without the new structure. The evolution of two new capabilities critical to cognitive performance is discussed: the evolution from non-specific anticipation to specific prediction, and the evolution of simple combinations of landmarks into detailed models of familiar places.