August 2009
Volume 9, Issue 8
Free
Vision Sciences Society Annual Meeting Abstract  |   August 2009
Coupling between fMR-adaptation and perceptual discrimination of upright and inverted faces
Author Affiliations
  • Sharon Gilaie-Dotan
    Dept. of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
  • Hagar Gelbard-Sagiv
    Dept. of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
  • Rafael Malach
    Dept. of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
Journal of Vision August 2009, Vol.9, 532. doi:10.1167/9.8.532
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Sharon Gilaie-Dotan, Hagar Gelbard-Sagiv, Rafael Malach; Coupling between fMR-adaptation and perceptual discrimination of upright and inverted faces. Journal of Vision 2009;9(8):532. doi: 10.1167/9.8.532.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Using the method of fMR-adaptation (also termed repetition suppression) we have recently demonstrated that the neuronal tuning to faces is very narrow, and follows the perceptual discrimination of subjects (Gilaie-Dotan and Malach, 2007). However, it is not clear whether this relationship between neuronal selectivity and perception is unique to faces or is a more general property of object representations. In order to examine this issue, we have compared our initial finding with an identical experiment in which the faces were inverted upside-down. This manipulation disrupts familiarity and expertise effects while preserving all low-level feature compositions. In the upright and inverted experiments, subjects were exposed to faces under four conditions: different faces, repeated presentation of an identical face and two levels of morphing which introduced small or large differences between faces. Regions of interest were localized using a separate face localizer experiment containing both upright and inverted faces. Behaviorally, we found that there was a significant broadening of the selectivity for inverted compared to upright faces. Examining the fMRI response amplitudes revealed only slight reduction in activity for inverted faces in the fusiform face area (FFA). Yet importantly, the tuning of fMR-adaptation in the FFA as well as in the object-related Lateral Occipital Complex (LOC) showed significant broadening for inverted faces. This broadening nicely correlated with the perceptual discrimination behavior for upright and inverted faces. Our results support the notion that the ability of human observers to discriminate objects and faces can be attributed to the tuning properties of single neurons underlying these representations rather than being a consequence of some vector representation of broadly tuned neurons. This mode of coding is apparently not unique to faces but appears to be a property of object representations in general, regardless of their familiarity or behavioral relevance.

Gilaie-Dotan, S. Gelbard-Sagiv, H. Malach, R. (2009). Coupling between fMR-adaptation and perceptual discrimination of upright and inverted faces [Abstract]. Journal of Vision, 9(8):532, 532a, http://journalofvision.org/9/8/532/, doi:10.1167/9.8.532. [CrossRef]
Footnotes
 This work was supported by ISF, Minnerva and Clore grants to R. Malach.
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×