The Ongoing Search for the Neuronal Correlate of Consciousness

A few decades ago the search for the neuronal correlates of consciousness was considered both technically intractable and philosophically questionable. Searching for a material substrate of phenomena accessible only from the first-person perspective appeared to be epistemically problematic. But the development of non-invasive imaging technologies and the availability of intracranial recordings from patients alleviated the imminent technical problems. Progress in the analysis of the connectome of the brain, and the introduction of multisite recordings from the cerebral cortex of animals led to a revision of concepts in the field of cognitive neuroscience, emphasizing principles of distributed processing in recurrent networks with non-linear dynamics, self-organization, and coding in high-dimensional-state space. These advances, together with the growing evidence for epigenetic shaping of brain functions by socio-cultural influences, pave the way for novel theories that attempt to bridge the gap between neuronal processes and subjective states.