Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Unconscious processing of orientation and color without primary visual cortex.

Jennifer L Boyer1, Stephenie Harrison, Tony Ro

  • 1Department of Psychology, Rice University, Houston, TX 77005-1892, USA.

Proceedings of the National Academy of Sciences of the United States of America
|November 3, 2005
PubMed
Summary

Blindsight, the ability to respond to visual stimuli without conscious awareness, was induced in healthy individuals by deactivating the primary visual cortex (V1) using transcranial magnetic stimulation (TMS). This demonstrates a functioning visual pathway bypassing V1 for processing orientation and color.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Sound frequency predicts the bodily location of auditory-induced tactile sensations in synesthetic and ordinary perception.

Neuroscience of consciousness·2026
Same author

Feelings on the tongue.

Journal of neurophysiology·2025
Same author

Neural Correlates of Visual Feature Binding.

Journal of cognitive neuroscience·2024
Same author

Unconscious Touch Perception After Disruption of the Primary Somatosensory Cortex.

Psychological science·2021
Same author

Editorial - Robert Rafal.

Cortex; a journal devoted to the study of the nervous system and behavior·2020
Same author

Visual Modulation of Resting State α Oscillations.

eNeuro·2019

Area of Science:

  • Neuroscience
  • Visual Perception
  • Cognitive Psychology

Background:

  • The primary visual cortex (V1) is crucial for conscious vision in humans.
  • Blindsight describes preserved visual processing in the absence of awareness, even with V1 damage.

Purpose of the Study:

  • To investigate blindsight phenomena in healthy individuals by transiently deactivating V1.
  • To determine if orientation and color discrimination are possible without conscious visual awareness.

Main Methods:

  • Transcranial magnetic stimulation (TMS) was used to induce a temporary, localized scotoma by deactivating V1.
  • Participants performed forced-choice discrimination tasks for visual targets (orientation and color) presented within the scotoma.
  • Performance was assessed under conditions of induced unawareness.

Related Experiment Videos

Main Results:

  • Participants demonstrated significantly above-chance performance on orientation discrimination tasks despite unawareness of visual targets.
  • Similarly, performance on color discrimination tasks was significantly above chance, even without conscious visual perception.
  • TMS successfully induced a transient blindsight state in a normal population.

Conclusions:

  • These findings support the existence of a functional geniculoextrastriate visual pathway that bypasses V1.
  • This pathway can process visual information, including orientation and color, independently of conscious awareness.
  • TMS is a viable tool for studying blindsight and visual processing in healthy individuals.