A systematic directional error in 2-D arm movements increases with increasing delay between visual target presentation and movement execution

Smyrnis, N; Gourtzelidis, P; Evdokimidis, I

dc.contributor.author	Smyrnis, N	en
dc.contributor.author	Gourtzelidis, P	en
dc.contributor.author	Evdokimidis, I	en
dc.date.accessioned	2014-03-01T01:49:45Z
dc.date.available	2014-03-01T01:49:45Z
dc.date.issued	2000	en
dc.identifier.issn	0014-4819	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/25901
dc.subject	direction of movement	en
dc.subject	motor control	en
dc.subject	frame of reference	en
dc.subject	visuomotor transformation	en
dc.subject	information transmission	en
dc.subject.classification	Neurosciences	en
dc.subject.other	PRIMATE MOTOR CORTEX	en
dc.subject.other	PLANAR REACHING MOVEMENTS	en
dc.subject.other	3-DIMENSIONAL SPACE	en
dc.subject.other	DIFFERENT PARTS	en
dc.subject.other	CELL DISCHARGE	en
dc.subject.other	INFORMATION	en
dc.subject.other	EXTENT	en
dc.subject.other	PREMOTOR	en
dc.subject.other	ACCURACY	en
dc.subject.other	MONKEY	en
dc.title	A systematic directional error in 2-D arm movements increases with increasing delay between visual target presentation and movement execution	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2000	en
heal.abstract	Forty-seven normal subjects performed two-dimensional arm movements on a digitizer board using a mouse device. The movements were projected on a computer monitor. Subjects were instructed to move the mouse using the whole arm from a center position to a peripheral target so that the projected movement would pass over the target without stopping on the target. A large number of targets (360) were used to cover the entire directional continuum. The direction of the arm movement was the parameter of interest, which was measured at an initial position, at one third of the distance towards the target, and at the vicinity of the target. Four conditions of delay between target presentation and movement execution were used (0, 2, 4, 6 s). A systematic directional error was observed at the initial portion of the trajectory. This error resulted from a clustering of movement directions on an axis that was perpendicular to the axis of the resting forearm before movement onset. This pattern of errors can be explained by the initial inertial anisotropy of the arm. As the trajectory evolved, a different directional error emerged, resulting from a clustering of movement directions in two orthogonal axes. This pattern of directional error increased in amplitude as the delay increased, in contrast to the error at the initial portion of the trajectory which remained invariant with increasing delay. Finally, the information transmitted by the movement direction was shown to increase with the evolution of the trajectory. The increase in delay resulted in a decrease in directional-information transmission. Tt is proposed that the directional bias towards the end of the movement trajectory might reflect the action of "movement primitives", that is patterns of muscle activation resulting from spinal interneuronal activation. It is further proposed that the directional bias observed at the vicinity of the target might reflect a loss of cortical directional information with increasing delay between target presentation and movement onset.	en
heal.publisher	SPRINGER VERLAG	en
heal.journalName	EXPERIMENTAL BRAIN RESEARCH	en
dc.identifier.isi	ISI:000087790200011	en
dc.identifier.volume	131	en
dc.identifier.issue	1	en
dc.identifier.spage	111	en
dc.identifier.epage	120	en