Waseda Institute for Advanced Study (WIAS)Waseda University

The sophistication of human perception far exceeds feedforward ‘deep’ neural networks in current AI, in large part because our perceptual processes are both monitored and controlled by the higher-order processes of perceptual metacognition. These include not only the generation of explicit confidence, but also implicit (i.e. automatic) judgments of reality versus imagination, of subjective similarity between stimuli, the deployment of attention, and adjustments of readout mechanisms that are sensitive to changes in noise level and representational drifts of early sensory content. It is difficult to imagine what subjective perception would be like without these processes. Perhaps, in that scenario, there would be ‘nothing it is like’ to perceive, i.e. perception without perceptual metacognition, broadly construed as above, may well be best conceptualized as nonconscious. Because these processes likely depend on the lateral prefrontal cortex, for which there is no homologue in rodents, it raises the intriguing possibility of the uniqueness of human/primate sentience.