Neuronal populations in the macaque prefrontal cortex (PFC) reliably encode visual stimuli even under conditions that challenge conscious perception and reduce post-perceptual processing. Recordings from the ventrolateral PFC during isolated trials and rapid serial visual presentation (RSVP) showed that stimulus identity could be decoded from population activity, with first signals at 60 ms and peak information at 150 ms. In RSVP, decoding accuracy dropped to chance by 200 ms as the next stimulus became decodable. Decoding in ventrolateral PFC was stronger than in posterior parietal cortex. The findings indicate PFC encodes visual information under conditions that limit conscious access and post-perceptual elaboration, raising questions about whether this reflects conscious access, phenomenal consciousness, or preconscious bottom-up processing.
An adversarial collaboration will test competing predictions from Global Neuronal Workspace Theory and Integrated Information Theory about the neural correlates of consciousness. Non-human primates and mice will perform a go-nogo task with supra-threshold visual and auditory stimuli while neural activity is recorded from multiple cortical areas using Neuropixels electrodes. To causally test timing and location predictions, prefrontal cortex activity will be manipulated via electrical stimulation in primates or optogenetic silencing in mice. The protocol details experimental design, analyses, divergent predictions, and anticipated outcomes.