 |
||||
|
||||
|
||||
|
||||
.gif?ad=17923&adview=true)
The Journal of Neuroscience, February 21, 2007, 27(8):2001-2012; doi:10.1523/JNEUROSCI.4274-06.2007
Previous Article | Next Article
Behavioral/Systems/Cognitive
Target Selection Signals for Arm Reaching in the Posterior Parietal Cortex
Hansjörg Scherberger andRichard A. Andersen Division of Biology, California Institute of Technology, Pasadena, California 91125
Correspondence should be addressed to Hansjörg Scherberger at his present address: Institute of Neuroinformatics, University and Federal Institute of Technology of Zürich, CH-8057 Zürich, Switzerland. Email: hjs{at}ini.phys.ethz.ch
The selection of visual stimuli as a target for a motor action may depend on external as well as internal variables. The parietal reach region (PRR) in the posterior parietal cortex plays an important role in the transformation of visual information into reach movement plans. We asked how neurons in PRR of macaque monkeys reflect the decision process of selecting one of two visual stimuli as a target for a reach movement. Spiking activity was recorded while the animal performed a free-choice task with one target presented in the preferred direction and the other in the off direction of the cell. Stimulus-onset asynchrony (SOA) was adjusted to ensure that both targets were selected equally often and the amount of reward was fixed. Neural activity in PRR was action specific for arm reaching and reflected the timing of the SOA as well as the selection of reach targets. In individual trials, activity was strongly linked to the choice of the animal, and, for the majority of cells, target selections could be predicted from activity in the stimulation or planning period, i.e., before the movement started. Many neurons were gain modulated by the fixation position, but gain modulation did not influence the target selection process directly. Finally, it was found that target selection for saccade movements was only weakly represented in PRR. These findings suggest that PRR is involved in decision making for reach movements and that separate cortical networks exist for target selection of different types of action.
Key words: sensorimotor transformation; motor system; movement planning; decision making; monkey; parietal reach region
Received Jan. 3, 2006; revised Jan. 10, 2007; accepted Jan. 10, 2007.
Correspondence should be addressed to Hansjörg Scherberger at his present address: Institute of Neuroinformatics, University and Federal Institute of Technology of Zürich, CH-8057 Zürich, Switzerland. Email: hjs{at}ini.phys.ethz.ch
Related articles in J. Neurosci.:
- Target Selection: Choice or Response?
- Carl P. T. Jackson, Neil B. Albert, Roberta D. Roberts, Joseph M. Galea, and Gabrielle Swait
J. Neurosci. 2007 27: 6079-6080.[Full Text]
This article has been cited by other articles:
D. Baldauf, H. Cui, and R. A. Andersen
The Posterior Parietal Cortex Encodes in Parallel Both Goals for Double-Reach Sequences
J. Neurosci., October 1, 2008; 28(40): 10081 - 10089.
[Abstract] [Full Text] [PDF]
J.-H. Song, N. Takahashi, and R. M. McPeek
Target Selection for Visually Guided Reaching in Macaque
J Neurophysiol, January 1, 2008; 99(1): 14 - 24.
[Abstract] [Full Text] [PDF]
C. P. T. Jackson, N. B. Albert, R. D. Roberts, J. M. Galea, and G. Swait
Target Selection: Choice or Response?
J. Neurosci., June 6, 2007; 27(23): 6079 - 6080.
[Full Text] [PDF]
|
|
|
|
 |
|