title: Closing the gates to consciousness: distractors activate a central inhibition process.
abstract: The paradigm of distractor-induced blindness has previously been used to track the transition from unconscious to conscious visual processing. In a variation of this paradigm used in this study, participants (n = 13) had to detect an orientation change of tilted bars (target) embedded in a dynamic random pattern; the onset of the target was signaled by the presentation of a color cue. Occasional orientation changes preceding the cue served as distractors and severely impaired the target's detection. ERPs showed that a frontal negativity was cumulatively activated by the distractors, and early sensory components were not affected. In a control condition, the target was defined by a coherent motion of the bars. Orientation changes preceding the motion target did not affect its detection, and the frontal suppression process was not observed. However, we obtained a significant reduction of the sensory components. The data support the notion that distractors that share the target's features trigger a cumulative inhibition process preventing the conscious representation of the inhibited features. Explorative source modeling suggests that this process originates in the pFC. A top-down modulation of sensory processing could not be observed.
authors.affiliation: Free University Berlin, Berlin, Germany. niedegg@zedat.fu-berlin.de
authors.forename: Michael
authors.initials: M
authors.lastname: Niedeggen
authors.forename: Lars
authors.initials: L
authors.lastname: Michael
authors.forename: Guido
authors.initials: G
authors.lastname: Hesselmann
mesh_terms: D000328:Adult; D003243:Consciousness / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009433:Neural Inhibition / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology*; D055815:Young Adult