Brain Mechanisms Underlying the Brief Maintenance of Seen and Unseen Sensory Information

• Published in: Neuron (Cambridge, Mass.) Vol. 92; no. 5; pp. 1122 - 1134
• Main Authors: King, Jean-Rémi, Pescetelli, Niccolo, Dehaene, Stanislas
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 07.12.2016; Elsevier Limited
• Subjects: Adult; attention; Awareness; backward masking; Brain - physiology; decoding; Discrimination; Female; Funding; Humans; machine learning; Magnetoencephalography; Male; Memory, Short-Term - physiology; Models, Neurological; perception; Perceptual Masking - physiology; Psychological Theory; Sensors; subliminal; temporal generalization; Unconscious (Psychology); visual awareness; Visual Perception - physiology; working memory; Young Adult; temporal generalization; working memory; subliminal; attention; visual awareness; machine learning; magnetoencephalography; decoding; backward masking; perception
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2016.10.051

Recent evidence of unconscious working memory challenges the notion that only visible stimuli can be actively maintained over time. In the present study, we investigated the neural dynamics underlying the maintenance of variably visible stimuli using magnetoencephalography. Subjects had to detect and mentally maintain the orientation of a masked grating. We show that the stimulus is fully encoded in early brain activity independently of visibility reports. However, the presence and orientation of the target are actively maintained throughout the brief retention period, even when the stimulus is reported as unseen. Source and decoding analyses revealed that perceptual maintenance recruits a hierarchical network spanning the early visual, temporal, parietal, and frontal cortices. Importantly, the representations coded in the late processing stages of this network specifically predicted visibility reports. These unexpected results challenge several theories of consciousness and suggest that invisible information can be briefly maintained within the higher processing stages of visual perception. •The link between working memory and visual awareness has recently been challenged•We study here the mechanism of unconscious maintenance with MEG and machine learning•Unseen stimuli can be partially maintained within high cortical assemblies•We show how to revise awareness theories to account for the maintenance of invisible stimuli King et al. used machine learning and magnetoencephalography to track the maintenance of subliminal images from brain activity. Their results demonstrate that invisible information can be briefly maintained in high cortical regions and consequently require the revision of theories of visual awareness.