Endpoints of arm movements to visual targets

Citation
Jj. Van Den Dobbelsteen et al., Endpoints of arm movements to visual targets, EXP BRAIN R, 138(3), 2001, pp. 279-287
Citations number
50
Categorie Soggetti
Neurosciences & Behavoir
Journal title
EXPERIMENTAL BRAIN RESEARCH
ISSN journal
00144819 → ACNP
Volume
138
Issue
3
Year of publication
2001
Pages
279 - 287
Database
ISI
SICI code
0014-4819(200106)138:3<279:EOAMTV>2.0.ZU;2-O
Abstract
Reaching out for objects with an unseen arm involves using both visual and kinesthetic information. Neither visual nor kinesthetic information is perf ect. Each is subject to both constant and variable errors. To evaluate how such errors influence performance in natural goal-directed movements, we as ked subjects to align a real 5-cm cube, which they held in their hand but c ould not see, with a three-dimensional visual simulation of such a cube. Th e simulated cube was presented at one of four target locations at the corne rs of an imaginary tetraeder. Subjects made successive, self-paced movement s between these target locations. They could not see anything except the si mulated cube throughout the experiment. Initial analysis of the spatial dis persion of movement endpoints demonstrated that the major source of errors under these conditions was visual. Further analysis of the relationship bet ween variability of the starting positions and endpoints showed that the er rors were primarily in judging the endpoint, rather than the direction or a mplitude of the required movement vector. The findings support endpoint con trol of human goal-directed movements.