Neuro term. 1. Total or partial loss of the ability to carry out learned body movements (e.g., whistling, clapping one's hands, and tying shoelaces), despite the presence of a healthy sensory-motor nervous system. 2. Inability to plan body movements, rather than problems carrying them out.
Usage: In a conversation, higher-level gestures (e.g., mime cues) mark the presence of conceptual thought. Seeing a steeple gesture in a listener, e.g., indicates a thoughtful (rather than an emotional, disagreeing, or uncertain) response to a speaker's remarks. Studies of apraxia suggest the neurological reasons for this view. Mime cues, such as imitating the act of threading a needle (unlike lower-level emotional gestures, such as expressing anger with a table-slap), are controlled by neocortical areas of the parietal and left frontal lobes--areas also used in speech.
RESEARCH REPORT: Higher-level learned
gestures and spoken words are both mediated (in right-handed individuals)
by premotor areas of the left frontal neocortex. Mime and steeple cues are
controlled a. by a hand-skills area (located
immediately anterior to the primary motor area for the digits and hands), and
b. by Broca's area (traditionally associated with
speech). As in proper grammatical speaking, our most complex hand gestures
(e.g., miming the manual process used to make a stone tool) depend on
prefrontal control to achieve the proper sequence of steps in the
manufacturing process. (N.B.: Damage to the left frontal
lobe not only causes apraxia but also a related speech defect known as
Neuro-notes. "The most commonly noted error of IMA [ideomotor apraxia] is using body part as object, for example, using the index finger as if it were the shaft of a screwdriver [rather than using the fingers to 'turn' the imagined shaft]" (Watson et al. 1992:685).
See also AGNOSIA, AKINESIA.
Copyright 1998 - 2012 (David B. Givens/Center for Nonverbal Studies)