How the visual cortex handles stimulus noise: insights from amblyopia

PLoS One. 2013 Jun 20;8(6):e66583. doi: 10.1371/journal.pone.0066583. Print 2013.

Abstract

Adding noise to a visual image makes object recognition more effortful and has a widespread effect on human electrophysiological responses. However, visual cortical processes directly involved in handling the stimulus noise have yet to be identified and dissociated from the modulation of the neural responses due to the deteriorated structural information and increased stimulus uncertainty in the case of noisy images. Here we show that the impairment of face gender categorization performance in the case of noisy images in amblyopic patients correlates with amblyopic deficits measured in the noise-induced modulation of the P1/P2 components of single-trial event-related potentials (ERP). On the other hand, the N170 ERP component is similarly affected by the presence of noise in the two eyes and its modulation does not predict the behavioral deficit. These results have revealed that the efficient processing of noisy images depends on the engagement of additional processing resources both at the early, feature-specific as well as later, object-level stages of visual cortical processing reflected in the P1 and P2 ERP components, respectively. Our findings also suggest that noise-induced modulation of the N170 component might reflect diminished face-selective neuronal responses to face images with deteriorated structural information.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amblyopia / physiopathology*
  • Analysis of Variance
  • Brain Mapping
  • Electroencephalography
  • Evoked Potentials, Visual / physiology*
  • Face
  • Female
  • Humans
  • Male
  • Middle Aged
  • Noise
  • Pattern Recognition, Visual / physiology*
  • Psychomotor Performance / physiology
  • Reaction Time / physiology
  • Visual Cortex / physiopathology*
  • Young Adult

Grants and funding

This work was supported by a grant from the Hungarian Scientific Research Fund (OTKA CNK 80369 to Z.V.), the National Development Agency (TÁMOP-4.2.1/B-09/1/KMR-2010-0001), and by the Szemünk Világa Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.