Asymmetric dichoptic masking in visual cortex of amblyopic macaque monkeys

Christopher Shooner, Luke E. Hallum, Romesh D. Kumbhani, Virginia García-Marín, Jenna G. Kelly, Najib J. Majaj, J. Anthony Movshon, Lynne Kiorpes

Research output: Contribution to journalArticle

Abstract

In amblyopia, abnormal visual experience leads to an extreme form of eye dominance, in which vision through the nondominant eye is degraded. A key aspect of this disorder is perceptual suppression: the image seen by the stronger eye often dominates during binocular viewing, blocking the image of the weaker eye from reaching awareness. Interocular suppression is the focus of ongoing work aimed at understanding and treating amblyopia, yet its physiological basis remains unknown. We measured binocular interactions invisual cortex of anesthetized amblyopic monkeys (female Macaca nemestrina), using 96-channel “Utah” arrays to record from populations of neurons in V1 and V2. In an experiment reported recently (Hallum et al., 2017), we found that reduced excitatory input from the amblyopic eye (AE) revealed a form of balanced binocular suppression that is unaltered in amblyopia. Here, we report on the modulation of the gain of excitatory signals from the AE by signals from its dominant fellow eye (FE). Using a dichoptic masking technique, we found that AE responses to grating stimuli were attenuated by the presentation of a noise mask to the FE, as in a normal control animal. Responses to FE stimuli, by contrast, could not be masked from the AE. We conclude that a weakened ability of the amblyopic eye to modulate cortical response gain creates an imbalance of suppression that favors the dominant eye.

Original languageEnglish (US)
Pages (from-to)8734-8741
Number of pages8
JournalJournal of Neuroscience
Volume37
Issue number36
DOIs
StatePublished - Sep 6 2017

    Fingerprint

Keywords

  • Anisometropia
  • Binocular interaction
  • Dichoptic masking
  • Macaque monkey
  • Strabismus
  • Visual cortex

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Shooner, C., Hallum, L. E., Kumbhani, R. D., García-Marín, V., Kelly, J. G., Majaj, N. J., Movshon, J. A., & Kiorpes, L. (2017). Asymmetric dichoptic masking in visual cortex of amblyopic macaque monkeys. Journal of Neuroscience, 37(36), 8734-8741. https://doi.org/10.1523/JNEUROSCI.1760-17.2017