Motor-related signals in the intraparietal cortex encode locations in a hybrid, rather than eye-centered reference frame.

Published

Journal Article

The reference frame used by intraparietal cortex neurons to encode locations is controversial. Many previous studies have suggested eye-centered coding, whereas we have reported that visual and auditory signals employ a hybrid reference frame (i.e., a combination of head- and eye-centered information) (Mullette-Gillman et al. 2005). One possible explanation for this discrepancy is that sensory-related activity, which we studied previously, is hybrid, whereas motor-related activity might be eye centered. Here, we examined the reference frame of visual and auditory saccade-related activity in the lateral and medial banks of the intraparietal sulcus (areas lateral intraparietal area [LIP] and medial intraparietal area [MIP]) of 2 rhesus monkeys. We recorded from 275 single neurons as monkeys performed visual and auditory saccades from different initial eye positions. We found that both visual and auditory signals reflected a hybrid of head- and eye-centered coordinates during both target and perisaccadic task periods rather than shifting to an eye-centered format as the saccade approached. This account differs from numerous previous recording studies. We suggest that the geometry of the receptive field sampling in prior studies was biased in favor of an eye-centered reference frame. Consequently, the overall hybrid nature of the reference frame was overlooked because the non-eye-centered response patterns were not fully characterized.

Full Text

Duke Authors

Cited Authors

  • Mullette-Gillman, OA; Cohen, YE; Groh, JM

Published Date

  • August 2009

Published In

Volume / Issue

  • 19 / 8

Start / End Page

  • 1761 - 1775

PubMed ID

  • 19068491

Pubmed Central ID

  • 19068491

Electronic International Standard Serial Number (EISSN)

  • 1460-2199

Digital Object Identifier (DOI)

  • 10.1093/cercor/bhn207

Language

  • eng

Conference Location

  • United States