The brainstem theory of consciousness asserts that raw, subjective experience, the "me inside," derives from computations implemented in the brainstem, not the cortex. The argument rests on philosophy's prototypical example of sentience, pain. Feeling pain does not require cortical processing. Nowhere in the cortex does electrical stimulation reliably evoke pain. Subcortical stimulation does....
The cerebral neocortex is essential for the complex feature extractions underlying sensory perception. Pain is an exception. Its adaptive message, fight or flee, is already available at the first central synapse. We propose that raw consciousness emerged with pain. Eons later the cortical supercomputer began providing complex computational output to the primeval circuitry of conscious pain...
Doubtless, the conscious brain integrates masses of information. But declaring that consciousness simply "emerges" when enough has accumulated, doesn't really explain how first person experience is implemented by neurons. Moreover, empirical observations challenge integrated information theory's (IIT) reliance on thalamo-cortical interactions as the information integrator. More likely, the...