Our growing understanding of the neural mechanisms underlying information awareness holds out the promise of clinical applications.
A first field of application concerns the hypothesis that certain brain pathologies affect more selectively the long-distance,top-down cortical networks associated with conscious access, while leaving largely intact the modular cortical systems responsible for non-conscious automated processing. In stark contrast to classical neuropsychology, which focuses on functional dissociations affecting specific skills and resulting from focal brain lesions, the global neuronal workspace model predicts that diffuse damage to either the cell bodies of long-axon neurons, or the long bundles of the corresponding white matter, should lead to deficits in a wide variety of effortful, conscious synthesis or executive control tasks, while leaving specialized non-conscious processing intact. Schizophrenia and autism can be analyzed from this angle. Despite the extent of their disorders, schizophrenic patients show a remarkable preservation of subliminal priming and other non-conscious or implicit phenomena (Danion, Meulemans, Kauffmann-Muller & Vermaat, 2001; Dehaene, Artiges et al., 2003). On the other hand, their threshold of conscious perception during masking is abnormally high (Del Cul, Dehaene & Leboyer, 2006). From this point of view, schizophrenia presents close parallels with other categories of pathology: on the one hand, patients with early-stage multiple sclerosis, where the extent of long-distance transcortical bundle pathology predicts the severity of the conscious perception disorder (Reuter et al., 2007; Reuter et al., 2009); and on the other hand, patients with focal frontal lobe brain lesions, particularly when the rostral frontal cortex is affected (Brodmann's area 10), who also present a subjective perception disorder of masked stimuli (Del Cul, Dehaene, Reyes, Bravo & Slachevsky, 2009).
