Frontoparietal cortex is involved in the explicit processing (awareness) of stimuli. Frontoparietal activation has also been found in studies of subliminal stimulus processing. We hypothesized that an impairment of top-down processes, involved in recurrent neuronal message-passing and the generation of long-latency electrophysiological responses, might provide a more reliable correlate of consciousness in severely brain-damaged patients, than frontoparietal responses. We measured effective connectivity during a mismatch negativity paradigm and found that the only significant difference between patients in a vegetative state and controls was an impairment of backward connectivity from frontal to temporal cortices. This result emphasizes the importance of top-down projections in recurrent processing that involve high-order associative cortices for conscious perception.
Preserved feedforward but impaired top-down processes in the vegetative state / M. Boly, M. I. Garrido, O. Gosseries, M. Bruno, P. Boveroux, C. Schnakers, M. Massimini, V. Litvak, S. Laureys, K. Friston. - In: SCIENCE. - ISSN 0036-8075. - 332:6031(2011 May 13), pp. 858-862.
|Titolo:||Preserved feedforward but impaired top-down processes in the vegetative state|
|Parole Chiave:||persistent vegetative state; young adult; humans; electroencephalography; Bayes Theorem; aged; awareness; models, statistical; parietal lobe; auditory perception; frontal lobe; consciousness; brain mapping; aged, 80 and over; temporal lobe; neural pathways; adult ; evoked potentials, auditory; middle aged; models, neurological; male; female; reaction time|
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
Settore MED/26 - Neurologia
|Data di pubblicazione:||13-mag-2011|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1126/science.1202043|
|Appare nelle tipologie:||01 - Articolo su periodico|