Brain Dynamics of Access to Consciousness
Author Information
Author(s): Antoine Del Cul, Sylvain Baillet, Stanislas Dehaene
Primary Institution: INSERM, Cognitive Neuroimaging Unit, IFR 49, Saclay, France
Hypothesis
What sequence of activations is evoked by subliminal masked stimuli and what additional sequence of brain events leads a stimulus to cross the threshold for conscious reportability?
Conclusion
The study concludes that conscious perception of masked stimuli corresponds to activity in a broadly distributed fronto-parieto-temporal network, occurring from about 300 ms after stimulus presentation.
Supporting Evidence
- Conscious perception corresponds to activity in a fronto-parieto-temporal network.
- Behavioral visibility ratings increased suddenly from SOA = 33 ms to SOA = 66 ms.
- Both objective and subjective data followed a sigmoidal curve as a function of SOA.
- The mean subjective threshold was 43.9 ms (SD= 10.5 ms).
- The P3 component exhibited the characteristic nonlinear signature seen in subjective reports.
Takeaway
When we see something, our brain has to work hard to make it visible, and this study shows that there are different stages in how our brain processes what we see, especially when something is hard to see.
Methodology
The study used high-density recordings of event-related potentials (ERPs) and cortical source reconstruction to assess brain activity evoked by masked stimuli.
Limitations
The study's conclusions may be affected by type I error due to multiple statistical comparisons.
Participant Demographics
12 right-handed native French speakers (7 women and 5 men; mean age: 23 years)
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.001
Digital Object Identifier (DOI)
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