Brain Dynamics Underlying the Nonlinear Threshold for Access to Consciousness

By Antoine Del Cul, Sylvain Baillet, Stanislas Dehaene. PLoS Biology, 2007

769 citations recorded by the source corpus.

When a flashed stimulus is followed by a backward mask, subjects fail to perceive it unless the target-mask interval exceeds a threshold duration of about 50 ms. Models of conscious access postulate that this threshold is associated with the time needed to establish sustained activity in recurrent cortical loops, but the brain areas involved and their timing remain debated. We used high-density recordings of event-related potentials (ERPs) and cortical source reconstruction to assess the time course of human brain activity evoked by masked stimuli and to determine neural events during which brain activity correlates with conscious reports. Target-mask stimulus onset asynchrony (SOA) was varied in small steps, allowing us to ask which ERP events show the characteristic nonlinear dependence with SOA seen in subjective and objective reports. The results separate distinct stages in mask-target interactions, indicating that a considerable amount of subliminal processing can occur early on in the occipito-temporal pathway (<250 ms) and pointing to a late (>270 ms) and highly distributed fronto-parieto-temporal activation as a correlate of conscious reportability.

Subfields: Cognitive Neuroscience

View Paper: https://www.semanticscholar.org/paper/cedac6abcc661f9b9c31ac7cd668c844f3fd2d68

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In Cognitive Neuroscience

Citations in the corpus

How can we measure awareness? An overview of current methods (2015, background): “…rather than corresponding exclusively to the phenomenology of awareness (the NCC), may also reflect processes that precede or follow conscious perception—its causes and consequences (Pins and Ffytche 2003; Del Cul et al. 2007; Melloni et al. 2007; Aru and Bachmann 2009a, b; Gaillard et al. 2009).”
Too real for comfort? Uncanny responses to computer generated faces (2009, background): “They may be separated through experimental procedures, such as the subliminal and supraliminal presentation of stimuli during the measurement of event-related potentials in the brain ( Del Cul, Baillet, & Dehaene, 2007 ).”
Experimental and theoretical approaches to conscious processing. (2011, background): “…parameters (e.g., Del Cul et al., 2007) and when comparing identical trials with or without conscious perception (e.g., Babiloni et al., 2006; Del Cul et al., 2007; Fernandez-Duque et al., 2003; Koivisto et al., 2008; Lamy et al., 2009; Niedeggen et al., 2001; Pins and Ffytche, 2003; Sergent et…”
Conscious and Nonconscious Processes:Distinct Forms of Evidence Accumulation? (2011, methodology): “Ideally, one should measure the extent of conscious perception on every single trial, possibly using a graded scale to capture even fi ne nuances of the percept ( Del Cul et al. 2007; Sergent et al. 2005; Sergent and Dehaene 2004).”
To See or Not to See: Pre-stimulus Alpha Phase Predicts Visual Awareness (2009, methodology): “Apart from the detected vs undetected ERP comparisons, in which we indicate the use of one-tailed statistical comparisons based on previous findings (Pourtois et al., 2006; Del Cul et al., 2007), all other statistics were conducted using two-tailed tests.”
Attacking Automatic Video Analysis Algorithms: A Case Study of Google Cloud Video Intelligence API (2017, background): “Empirical studies have shown that human visual system needs about 50 ms to process and comprehend every single image [17].”
Conscious Processing and the Global Neuronal Workspace Hypothesis (2020, background): “…for auditory or visual conscious perception is associated with a sudden increase in the P300 component, and only this component vanishes almost entirely under inattention conditions (Berkovitch et al., 2018; Charles et al., 2014; Del Cul et al., 2007) or during sleep (Strauss et al., 2015).”
Recovery of cortical effective connectivity and recovery of consciousness in vegetative patients (2012, positive): “…consider- ations (Tononi, 2004; Laureys, 2005; Dehaene et al., 2006; Tononi and Koch, 2008; Seth et al., 2008) as well as experimental data (Del Cul et al., 2007; Alkire et al., 2008) suggest that a basic requirement for consciousness is that multiple, specialized areas of the…”
Error awareness and the error-related negativity: evaluating the first decade of evidence (2012, background): “…could indeed have the bimodal distribution that Frontiers in Human Neuroscience www.frontiersin.org April 2012 | Volume 6 | Article 88 | 12 would be predicted based on the Pe/p300-equivalency hypothesis and the findings of Del Cul et al. (2007), and signify the actual expression of error awareness.”
Toward a computational theory of conscious processing (2013, neutral): “A subliminal stimulus may induce above-chance performance, behavioral priming, and a small amount of brain activity in narrowly defined brain networks, but these measures often increase dramatically as soon as the subject reports seeing the stimulus, especially in high-level areas [46 ,60,61 ].”
The Neural Basis of the Dynamic Unconscious (2011, background): “Using ERPs, Del Cul et al. (2007) found that subliminal processing can occur early on in the occipito–temporal pathway (<250 ms poststimu- lus), but that conscious perception of masked stimuli corresponds to later activity (~300 ms poststimulus) in a broadly distributed fronto–parieto–temporal…”
The Brain's Router: A Cortical Network Model of Serial Processing in the Primate Brain (2010, background): “The P3 component can only be detected in seen trials, in an all-or-none fashion [73,104].”