Coupling the State and Contents of Consciousness

A fundamental feature of consciousness is that its contents depend on its state. The authors propose that both state and contents depend on the activity of cortical layer 5 pyramidal (L5p) neurons. These neurons couple cortico-cortical and thalamo-cortical loops, forming a thalamo-cortical broadcasting system where L5p cells are central. This coupling corresponds to the coupling between state and contents of consciousness. The perspective predicts that cortical processing without L5p neurons will be unconscious, suggesting L5p neurons have a central role in the mechanisms underlying consciousness.

Study at a glance

Abstract

One fundamental feature of consciousness is that the contents of consciousness depend on the state of consciousness. Here, we propose an answer to why this is so: both the state and the contents of consciousness depend on the activity of cortical layer 5 pyramidal (L5p) neurons. These neurons affect both cortical and thalamic processing, hence coupling the cortico-cortical and thalamo-cortical loops with each other. Functionally this coupling corresponds to the coupling between the state and the contents of consciousness. Together the cortico-cortical and thalamo-cortical loops form a thalamo-cortical broadcasting system, where the L5p cells are the central elements. This perspective makes one quite specific prediction: cortical processing that does not include L5p neurons will be unconscious. More generally, the present perspective suggests that L5p neurons have a central role in the mechanisms underlying consciousness.