Monday, February 21, 2005
11:00 AM
CSB 209
Michael Arbib
U. Southern California
How the Brain Evolved So We Could Have Language (Distinguished Seminar Series)
The Mirror System Hypothesis (MSH) on the evolution of the language-ready brain posits several stages: action recognition grounds imitation of pragmatic actions of the hands, this in turn grounds pantomime as a new form of communication based on displacement of hand gestures to mimic other degrees of freedom; the repertoire is then extended as familiar actions are recursively varied and combined. Conventional codes then supplement and increasingly supplant pantomime to yield protosign, a combinatorially open repertoire of manual gestures, which provides the scaffolding for the emergence of protospeech (which thus owes relatively little to non-human vocalizations), with protosign and protospeech then developing in an expanding spiral. It is argued that these stages involve biological evolution of both brain and body. By contrast, it is argued that the progression from protolanguage (protosign and protospeech) to languages with full-blown syntax and compositional semantics was a historical phenomenon involving few if any further biological changes.