Abstract
Psychophysiological studies with electroencephalography, focusing on the dynamical aspect of neural correlate of consciousness, reported that visual awareness negativity and P3 enhancement are observed at a latency, 200–300 ms after the visual stimulus onset, when the visual stimulus is consciously perceived. However, access processing to visual awareness (APVA) immediately before conscious perception still remains at the earlier stage of visual sensory processing, though there is little known regarding this subject. The present study hypothesized that visual mismatch negativity (vMMN), which reflects automatic change detection at a latency of 130–250 ms, might be involved in the APVA. In a previous study, vMMN was reported to be evoked by the deviant stimulus that is not consciously perceived in binocular rivalry. To clarify whether the visual change detection affects APVA, we conducted a modified experiment of oddball paradigm on binocular rivalry. The results showed a significant correlation between enhancement of vMMN amplitude and facilitation of perceptual alternation when the unconscious deviant was presented. This implies that vMMN is relevant to the APVA, which is a novel role of vMMN. In early visual processing, the attentional mechanism associated with vMMN is suggested to play an important role in unconscious neural processing at an earlier stage of visual awareness.
Highlights
Previous neuropsychological studies on visual awareness have been trying to elucidate neural processes that are correlated with the subjective conscious experience, analyzing the differences in neural activities between when the visual stimulus is consciously perceived and when it is not consciously perceived (Koivisto and Revonsuo, 2010; Dehaene and Changeux, 2011; Aru et al, 2012; Silverstein et al, 2015; Koch et al, 2016)
The present study hypothesized a type of unconscious neural processing that determines whether the unconscious stimulus is consciously perceived or not [hereafter, we call the neural processing as access processing to visual awareness (APVA)] at the earlier stage of visual sensory processing than the emergence of visual awareness negativity (VAN)
In order to clarify the relationship between visual mismatch negativity (vMMN) and APVA, we focused on inter-individual variability and examined whether vMMN enhancement is correlated with an increase in the proportion of perceptual alternation across participants, as in our previous studies (Urakawa et al, 2017a, 2018)
Summary
Previous neuropsychological studies on visual awareness have been trying to elucidate neural processes that are correlated with the subjective conscious experience, analyzing the differences in neural activities between when the visual stimulus is consciously perceived and when it is not consciously perceived (Koivisto and Revonsuo, 2010; Dehaene and Changeux, 2011; Aru et al, 2012; Silverstein et al, 2015; Koch et al, 2016). The present study hypothesized a type of unconscious neural processing that determines whether the unconscious stimulus is consciously perceived or not [hereafter, we call the neural processing as access processing to visual awareness (APVA)] at the earlier stage of visual sensory processing than the emergence of VAN. According to previous studies (Prinz, 2011; Bor and Seth, 2012; Cohen et al, 2012), attentional mechanisms would impinge on visual processing earlier than the emergence of VAN; the attentional mechanism would contribute to APVA. These attentional mechanisms were considered to be restricted to those accompanied by visual processing earlier than VAN. The attentional mechanism appears to facilitate visual processing for the unconscious visual stimulus, so that the stimulus information crosses the boundary between consciousness and unconsciousness
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
