Robust single trial identification of conscious percepts triggered by sensory events of variable saliency.
The neural correlates of visual awareness are elusive because of its fleeting nature. Here we have addressed this issue by using single trial statistical "brain reading" of neurophysiological event related (ERP) signatures of conscious perception of visual attributes with different levels of saliency. Behavioral reports were taken at every trial in 4 experiments addressing conscious access to color, luminance, and local phase offset cues. We found that single trial neurophysiological signatures of target presence can be observed around 300 ms at central parietal sites. Such signatures are significantly related with conscious perception, and their probability is related to sensory saliency levels. These findings identify a general neural correlate of conscious perception at the single trial level, since conscious perception can be decoded as such independently of stimulus salience and fluctuations of threshold levels. This approach can be generalized to successfully detect target presence in other individuals.
Visual Neuroscience Laboratory, IBILI - Institute for Biomedical Imaging and Life Sciences, University of Coimbra, Coimbra, Portugal ; Institute for Nuclear Sciences Applied to Health (ICNAS), Brain Imaging Network of Portugal, University of Coimbra, Coimbra, Portugal.
Marta
M
Teixeira
Institute for Systems and Robotics (ISR), University of Coimbra, Coimbra, Portugal.
Gabriel
G
Pires
Visual Neuroscience Laboratory, IBILI - Institute for Biomedical Imaging and Life Sciences, University of Coimbra, Coimbra, Portugal ; Institute for Nuclear Sciences Applied to Health (ICNAS), Brain Imaging Network of Portugal, University of Coimbra, Coimbra, Portugal.
Miguel
M
Raimundo
Department of Physics, University of Minho, Braga, Portugal.
Sérgio
S
Nascimento
Department of Physics, University of Beira Interior, Covilhã, Portugal.
Vasco
V
Almeida
Visual Neuroscience Laboratory, IBILI - Institute for Biomedical Imaging and Life Sciences, University of Coimbra, Coimbra, Portugal ; Institute for Nuclear Sciences Applied to Health (ICNAS), Brain Imaging Network of Portugal, University of Coimbra, Coimbra, Portugal.
Miguel
M
Castelo-Branco
D000328:Adult; D018913:Event-Related Potentials, P300; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D013360:Subliminal Stimulation; D014796:Visual Perception; D055815:Young Adult