The Articulate Hand Summary and Analysis

The French physician Paul Broca identifies an area in the brain that controls speech by examining the brain of a stroke patient who is left speechless. Medical student Karl Wernicke identifies a second brain region that causes a language impairment he called aphasia. Although they both identify an area that disrupts speech, neither identifies these areas as originating or causing speech, according to author Steve Pinker. However, scientific belief identifies the left brain hemisphere as specialized for language and the consensus is that it has been preadapted for speech for over 100,000 years.

Further studies at the University of New Mexico in correlation with Gallaudet University propose a "continuum of communicative movements" that has four levels. They range from a primate display of aggression, iconic hand gestures like an "L-shape" to represent a gun, cultural gestures like getting...