Neural correlates of visual consciousness - version 1
Research type
Research Study
Full title
The neural correlates of conscious visual experience in normal and brain damaged human subjects
IRAS ID
292019
Contact name
Semir Zeki
Contact email
Sponsor organisation
University College London
Clinicaltrials.gov Identifier
Z6364106/2020/12/32, UCL Data Protection Number
Duration of Study in the UK
1 years, 6 months, 1 days
Research summary
The proposed research addresses the question of what neural systems are
engaged when normal and brain damaged human subjects (aged 20 to 65)
experience the visual world consciously. In both, near threshold stimuli,
especially moving visual stimuli, can be made to activate visual brain centres
even though the subjects are aware of them on some presentations but not on
others. We are searching for patterns of brain activity that correlate with the
conscious experience of such stimuli to learn whether there is any specific
pattern that correlates with consciously experienced visual stimuli as opposed to
visual stimuli which activate the brain but of which subjects are not consciously
aware. The work will be of enormous benefit to understanding the important
issue of what the minimum necessary conditions for conscious vision are and at
the same time be of great benefit to patients blinded by lesions, in determining
their visual capacities, something that they do not always know.
The study will be conducted at University College London – patients being seen
and studied at the National Hospital, Queen Square and the Institute of Cognitive
Neuroscience, while normal subjects will be studied for their visual capacities at
University College London. Sessions for determining such visual capacities
formally usually last between 60 and 90 minutes, with subjects allowed limitless
rest periods if required. All subjects will be scanned with functional magnetic
resonance imaging for brain activity, at the Functional Imaging Laboratory at
UCL. The stimuli used in these scanning experiments will be those determined
from the pre-scan experiments to fall within the supra- and infra-threshold for
each subjects individually. Scanning sessions typically last 90 minutes (which
includes the preparation phase); subjects will be in the scanner itself for a period of about 30 minutes
We estimate that the study will last three years.REC name
Yorkshire & The Humber - South Yorkshire Research Ethics Committee
REC reference
21/YH/0136
Date of REC Opinion
19 Jul 2021
REC opinion
Further Information Favourable Opinion