Dehaene et al - Conscious, preconscious, and subliminal processing Flashcards
Consciousness
Vigilance and ‘states of vigilance’
Maintains thalamocortical systems in a receptive state, lowering threshold for sensory inputs. More cerebral blood flow in brainstem and thalamus.
‘states of vigilance’ to refer to the non-transitive meaning, i.e. a continuum of states which encompasses wakefulness, sleep, coma, anesthesia, etc.
Attentional Blink
Event-related potentials show similar responses for invisible and visible words, indicating consciousness depends on attention.
Top-Down Amplification
Increased activity in parietal, prefrontal, and anterior cingulate areas correlates with conscious perception in brain scans.
Subliminal Processing
Occurs when stimuli lack sufficient bottom-up activation, leading to inaccessible information.
Preconscious Processing
Involves potential for conscious access but remains unnoticed due to lack of attention.
Temporal Attention
Subliminal priming persists with temporal attention but vanishes without it.
Spatial Attention
Modulates unconscious processing, as shown by experiments with blindsight patients.
Masking with Attention
Contrasts between masked and unmasked stimuli reveal differences in subliminal and conscious processing.
Stimuli at Threshold
Even when attended, stimuli at sensory threshold may vary in perception, highlighting contrasts between subliminal and conscious stimuli.
Information Not Encoded in Firing
Knowledge stored latently remains inaccessible until it triggers neural firing.
Information Not Explicitly Represented in Firing
Aspects of the visual scene must be represented by neurons with unambiguous firing, amplified by top-down attention for conscious accessibility.
Information Coded by Functionally Disconnected Neurons
Information remains non-conscious if relevant neurons lack bidirectional projections, preventing assembly with parietal and prefrontal cortices.
