TY - JOUR
T1 - Motor directional tuning across brain areas
T2 - Directional resonance and the role of inhibition for directional accuracy
AU - Mahan, Margaret Y.
AU - Georgopoulos, Apostolos P.
PY - 2013/4/26
Y1 - 2013/4/26
N2 - Motor directional tuning (Georgopoulos et al., 1982) has been found in every brain area in which it has been sought for during the past 30-odd years. It is typically broad, with widely distributed preferred directions and a population signal that predicts accurately the direction of an upcoming reaching movement or isometric force pulse (Georgopoulos et al., 1992). What is the basis for such ubiquitous directional tuning? How does the tuning come about? What are the implications of directional tuning for understanding the brain mechanisms of movement in space? This review addresses these questions in the light of accumulated knowledge in various sub-fields of neuroscience and motor behavior. It is argued (a) that direction in space encompasses many aspects, from vision to muscles, (b) that there is a directional congruence among the central representations of these distributed "directions" arising from rough but orderly topographic connectivities among brain areas, (c) that broad directional tuning is the result of broad excitation limited by recurrent and non-recurrent (i.e. direct) inhibition within the preferred direction loci in brain areas, and (d) that the width of the directional tuning curve, modulated by local inhibitory mechanisms, is a parameter that determines the accuracy of the directional command.
AB - Motor directional tuning (Georgopoulos et al., 1982) has been found in every brain area in which it has been sought for during the past 30-odd years. It is typically broad, with widely distributed preferred directions and a population signal that predicts accurately the direction of an upcoming reaching movement or isometric force pulse (Georgopoulos et al., 1992). What is the basis for such ubiquitous directional tuning? How does the tuning come about? What are the implications of directional tuning for understanding the brain mechanisms of movement in space? This review addresses these questions in the light of accumulated knowledge in various sub-fields of neuroscience and motor behavior. It is argued (a) that direction in space encompasses many aspects, from vision to muscles, (b) that there is a directional congruence among the central representations of these distributed "directions" arising from rough but orderly topographic connectivities among brain areas, (c) that broad directional tuning is the result of broad excitation limited by recurrent and non-recurrent (i.e. direct) inhibition within the preferred direction loci in brain areas, and (d) that the width of the directional tuning curve, modulated by local inhibitory mechanisms, is a parameter that determines the accuracy of the directional command.
KW - Directional precision
KW - Inhibitory mechanisms
KW - Motor directional tuning
KW - Motor resonance
KW - Movement direction
UR - http://www.scopus.com/inward/record.url?scp=84876926938&partnerID=8YFLogxK
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U2 - 10.3389/fncir.2013.00092
DO - 10.3389/fncir.2013.00092
M3 - Article
C2 - 23720612
AN - SCOPUS:84876926938
SN - 1662-5110
JO - Frontiers in Neural Circuits
JF - Frontiers in Neural Circuits
IS - APR 2013
ER -