MRC Cognition and Brain Sciences UnitCBSU bibliography search
To request a reprint of a CBSU publication, please
click here to send us an email (reprints may not be available for all publications)
Absence of Face-specific Cortical Activity in the Complete Absence of Awareness: Converging Evidence from Functional Magnetic Resonance Imaging and Event-related Potentials
Authors:
RodrÃguez, V., THOMPSON, R., Stokes, M., Brett, M., ,Alvarez, I., Valdes-Sosa, M., DUNCAN, J.
Reference:
Journal of Cognitive Neuroscience, 24(2), 396-415
Year of publication:
2012
CBU number:
7379
Abstract:
In this study, we explored the neural correlates of perceptual awareness during a masked face detection task. To assess awareness more precisely than in previous studies, participants employed a 4-point scale to rate subjective visibility. An event-related fMRI and a high-density ERP study were carried out. Imaging data showed that conscious face detection was linked to activation of fusiform and occipital face areas. Frontal and parietal regions, including the pre-SMA, inferior frontal sulcus, anterior insula/frontal operculum, and intraparietal sulcus, also responded strongly when faces were consciously perceived. In contrast, no brain area showed face-selective activity when participants reported no impression of a face. ERP results showed that conscious face detection was associated with enhanced N170 and also with the presence of a second negativity around 300 msec and a slow positivity around 415 msec. Again, face-related activity was absent when faces were not consciously perceived. We suggest that, under conditions of backward masking, ventral stream and fronto-parietal regions show similar, strong links of face-related activity to conscious perception and stress the importance of a detailed assessment of awareness to examine activity related to unseen stimulus events.
