Conscious Level Of Task-irrelevant Patterns In The Inattentional Blindness Paradigm

The neural correlates of consciousness(NCC),which refer to the neural activity that underlies conscious perception,have been a long-standing topic of debate in the field of cognitive neuroscience.The focus has primarily been on the early visual awareness negativity(VAN)located in the posterior occipital region and the late positivity(LP or P3b)widely distributed in the anterior frontal-parietal regions.Recent studies using no-report paradigms have demonstrated that P3b reflects post-perceptual processing related to task or response demands,rather than visual awareness.However,studies using report paradigms have indicated that P3b is an NCC and reflects the processing of high-level stimulus properties.To further investigate the functional significance of P3b in visual awareness,the current study used a no-report inattentional blindness paradigm to explore the conscious processing of task-irrelevant real-world objects.The current study consisted of three phases with identical experimental stimulus settings.In the first phase,participants performed a dot detection task while real-world object outlines appeared in the center of the screen at random intervals,which were classified into awareness group and inattentional blindness group based on the participant’s awareness of unexpected patterns.In the second phase,participants were required to perform the same dot detection task as in the first phase,but all participants were aware of the task-irrelevant patterns.In the third phase,real-world object outlines were task-relevant stimuli,and participants were asked to identify specific real-world objects.The results showed that VAN(260-340 ms)were evoked when participants were aware of the real-world object in all three phases,regardless of group,while P3b(450-600 ms)were only evoked in the second and third phases.This result indicates that VAN components can serve as the reliable neural correlates of visual awareness,while P3b may be not a neural indicator of visual awareness.In addition,P3b was significant evoked not only when real-world object stimuli were task-relevant(phase 3)but also when they were task-irrelevant(phase 2),indicating that P3b does not specifically reflect post-perceptual processing related to task or response requirements,but may also reflect the high-level conscious processing of task-irrelevant real-world objects.In order to ensure that participants were clearly aware of the real-world object under task-irrelevant conditions,Experiment 2 changed the presentation mode of the dot array from continuous stimuli in Experiment 1 to occasional stimuli to increase the visibility of the real-world object.The results showed that significant VAN and P3b components were evoked for both groups in all three phases of Experiment 2,regardless of task relevance.Experiment 2 results suggest that under task-irrelevant conditions,the P3b component may reflect the high-level conscious processing of task-irrelevant real-world objects,while under task-relevant conditions,the P3b component may reflect post-perceptual processing related to the participant’s subjective report on perceptual information acquisition.The current study demonstrates through two experiments that(1)P3b does not reflect post-perceptual processing related to task requirements as previously thought and(2)P3b may reflect high-level conscious processing of task-irrelevant real-world objects.