* Bottom-up and top-down visuomotor responses to action observation.
- Action observation produces automatic "mirror" responses in the observers' motor system. However, in daily life, nonimitative actions are often required to be produced in response to others' acts, generating a conflict between automatic and voluntary responses. First, we used single-pulse transcranial magnetic stimulation (TMS) to assess the temporal dynamics of motor output in healthy volunteers preparing rule-based counter-imitative motor responses cued by different observed hand movements. Second, we applied the same paradigm after 1-Hz repetitive TMS (rTMS) of the left posterior parietal cortex (PPC) and of the left dorsolateral prefrontal cortex (dlPFC). The results showed an early (150 ms from onset of visual stimuli) stimulus-driven mirror response that was followed by a later (300 ms) rule-based nonmirror response. rTMS applied to the PPC modulated only the early mirror response. Conversely, rTMS to the dlPFC modulated specifically the late rule-based motor response. The data indicate that a fast bottom-up process mediated by the dorsal visual stream produces automatic imitative responses. Arbitrary rule-based visuomotor associations are on the contrary mediated by a slower system, relying on the prefrontal cortex. The 2 systems are mutually independent and compete for motor output in socially relevant situations only at a distal level.
=>制度組織体系的方式, システム, 組織, 整然とした手順, (思想などの)体系, 体制
Overview of noun system
The noun system has 9 senses (first 8 from tagged texts)
1. (43) system -- (instrumentality that combines interrelated interacting artifacts designed to work
as a coherent entity; "he bought a new stereo system"; "the system consists of a motor and a small
computer")
2. (23) system, scheme -- (a group of independent but interrelated elements comprising a unified
whole; "a vast system of production and distribution and consumption keep the country going")
3. (14) system -- ((physical chemistry) a sample of matter in which substances in different phases
are in equilibrium; "in a static system oil cannot be replaced by water on a surface"; "a system
generating hydrogen peroxide")
4. (10) system, system of rules -- (a complex of methods or rules governing behavior; "they have to
operate under a system they oppose"; "that language has a complex system for indicating gender")
5. (8) arrangement, organization, organisation, system -- (an organized structure for arranging or
classifying; "he changed the arrangement of the topics"; "the facts were familiar but it was in the
organization of them that he was original"; "he tried to understand their system of classification")
6. (7) system -- (a group of physiologically or anatomically related organs or parts; "the body has
a system of organs for digestion")
7. (6) system -- (a procedure or process for obtaining an objective; "they had to devise a system
that did not depend on cooperation")
8. (1) system -- (the living body considered as made up of interdependent components forming a
unified whole; "exercise helped him get the alcohol out of his system")
9. organization, organisation, system -- (an ordered manner; orderliness by virtue of being
methodical and well organized; "his compulsive organization was not an endearing quality"; "we can't
do it unless we establish some system around here")
--- WordNet end ---