Integration of target and hand position signals in the posterior parietal cortex: Effects of workspace and hand vision

Christopher Buneo, Richard A. Andersen

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Previous findings suggest the posterior parietal cortex (PPC) contributes to arm movement planning by transforming target and limb position signals into a desired reach vector. However, the neural mechanisms underlying this transformation remain unclear. In the present study we examined the responses of 109 PPC neurons as movements were planned and executed to visual targets presented over a large portion of the reaching workspace. In contrast to previous studies, movements were made without concurrent visual and somatic cues about the starting position of the hand. For comparison, a subset of neurons was also examined with concurrent visual and somatic hand position cues. We found that single cells integrated target and limb position information in a very consistent manner across the reaching workspace. Approximately two-thirds of the neurons with significantly tuned activity (42/61 and 30/46 for left and right workspaces, respectively) coded targets and initial hand positions separably, indicating no hand-centered encoding, whereas the remaining one-third coded targets and hand positions inseparably, in a manner more consistent with the influence of hand-centered coordinates. The responses of both types of neurons were largely invariant with respect to the presence or absence of visual hand position cues, suggesting their corresponding coordinate frames and gain effects were unaffected by cue integration. The results suggest that the PPC uses a consistent scheme for computing reach vectors in different parts of the workspace that is robust to changes in the availability of somatic and visual cues about hand position.

Original languageEnglish (US)
Pages (from-to)187-199
Number of pages13
JournalJournal of Neurophysiology
Volume108
Issue number1
DOIs
StatePublished - Jul 1 2012
Externally publishedYes

Fingerprint

Parietal Lobe
Hand
Cues
Neurons
Extremities
Arm

Keywords

  • Arm
  • Coordinates
  • Eye
  • Reference frames
  • Transformations

ASJC Scopus subject areas

  • Physiology
  • Neuroscience(all)

Cite this

Integration of target and hand position signals in the posterior parietal cortex : Effects of workspace and hand vision. / Buneo, Christopher; Andersen, Richard A.

In: Journal of Neurophysiology, Vol. 108, No. 1, 01.07.2012, p. 187-199.

Research output: Contribution to journalArticle

@article{2b5c0dd1e6c94b6cb4254a58a5e177be,
title = "Integration of target and hand position signals in the posterior parietal cortex: Effects of workspace and hand vision",
abstract = "Previous findings suggest the posterior parietal cortex (PPC) contributes to arm movement planning by transforming target and limb position signals into a desired reach vector. However, the neural mechanisms underlying this transformation remain unclear. In the present study we examined the responses of 109 PPC neurons as movements were planned and executed to visual targets presented over a large portion of the reaching workspace. In contrast to previous studies, movements were made without concurrent visual and somatic cues about the starting position of the hand. For comparison, a subset of neurons was also examined with concurrent visual and somatic hand position cues. We found that single cells integrated target and limb position information in a very consistent manner across the reaching workspace. Approximately two-thirds of the neurons with significantly tuned activity (42/61 and 30/46 for left and right workspaces, respectively) coded targets and initial hand positions separably, indicating no hand-centered encoding, whereas the remaining one-third coded targets and hand positions inseparably, in a manner more consistent with the influence of hand-centered coordinates. The responses of both types of neurons were largely invariant with respect to the presence or absence of visual hand position cues, suggesting their corresponding coordinate frames and gain effects were unaffected by cue integration. The results suggest that the PPC uses a consistent scheme for computing reach vectors in different parts of the workspace that is robust to changes in the availability of somatic and visual cues about hand position.",
keywords = "Arm, Coordinates, Eye, Reference frames, Transformations",
author = "Christopher Buneo and Andersen, {Richard A.}",
year = "2012",
month = "7",
day = "1",
doi = "10.1152/jn.00137.2011",
language = "English (US)",
volume = "108",
pages = "187--199",
journal = "Journal of Neurophysiology",
issn = "0022-3077",
publisher = "American Physiological Society",
number = "1",

}

TY - JOUR

T1 - Integration of target and hand position signals in the posterior parietal cortex

T2 - Effects of workspace and hand vision

AU - Buneo, Christopher

AU - Andersen, Richard A.

PY - 2012/7/1

Y1 - 2012/7/1

N2 - Previous findings suggest the posterior parietal cortex (PPC) contributes to arm movement planning by transforming target and limb position signals into a desired reach vector. However, the neural mechanisms underlying this transformation remain unclear. In the present study we examined the responses of 109 PPC neurons as movements were planned and executed to visual targets presented over a large portion of the reaching workspace. In contrast to previous studies, movements were made without concurrent visual and somatic cues about the starting position of the hand. For comparison, a subset of neurons was also examined with concurrent visual and somatic hand position cues. We found that single cells integrated target and limb position information in a very consistent manner across the reaching workspace. Approximately two-thirds of the neurons with significantly tuned activity (42/61 and 30/46 for left and right workspaces, respectively) coded targets and initial hand positions separably, indicating no hand-centered encoding, whereas the remaining one-third coded targets and hand positions inseparably, in a manner more consistent with the influence of hand-centered coordinates. The responses of both types of neurons were largely invariant with respect to the presence or absence of visual hand position cues, suggesting their corresponding coordinate frames and gain effects were unaffected by cue integration. The results suggest that the PPC uses a consistent scheme for computing reach vectors in different parts of the workspace that is robust to changes in the availability of somatic and visual cues about hand position.

AB - Previous findings suggest the posterior parietal cortex (PPC) contributes to arm movement planning by transforming target and limb position signals into a desired reach vector. However, the neural mechanisms underlying this transformation remain unclear. In the present study we examined the responses of 109 PPC neurons as movements were planned and executed to visual targets presented over a large portion of the reaching workspace. In contrast to previous studies, movements were made without concurrent visual and somatic cues about the starting position of the hand. For comparison, a subset of neurons was also examined with concurrent visual and somatic hand position cues. We found that single cells integrated target and limb position information in a very consistent manner across the reaching workspace. Approximately two-thirds of the neurons with significantly tuned activity (42/61 and 30/46 for left and right workspaces, respectively) coded targets and initial hand positions separably, indicating no hand-centered encoding, whereas the remaining one-third coded targets and hand positions inseparably, in a manner more consistent with the influence of hand-centered coordinates. The responses of both types of neurons were largely invariant with respect to the presence or absence of visual hand position cues, suggesting their corresponding coordinate frames and gain effects were unaffected by cue integration. The results suggest that the PPC uses a consistent scheme for computing reach vectors in different parts of the workspace that is robust to changes in the availability of somatic and visual cues about hand position.

KW - Arm

KW - Coordinates

KW - Eye

KW - Reference frames

KW - Transformations

UR - http://www.scopus.com/inward/record.url?scp=84863300031&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84863300031&partnerID=8YFLogxK

U2 - 10.1152/jn.00137.2011

DO - 10.1152/jn.00137.2011

M3 - Article

C2 - 22457457

AN - SCOPUS:84863300031

VL - 108

SP - 187

EP - 199

JO - Journal of Neurophysiology

JF - Journal of Neurophysiology

SN - 0022-3077

IS - 1

ER -