Overview

Cortex is proposed to be the organ of mind for conscious and unconscious functions. Is it true?

This debate has lasted because cortex is the most adaptable organ in the body. Its development can vary enormously at any choice point in its trajectory. Cortex is a kind of “species.” In waking cortex, adaptive neuronal signaling is also constantly changing, using moments of conscious “integration and ignition” as the major adaptive event (Dehaene, 2014).

The term “mind” was brought back in the 1950s, after a long behavioristic exile circa 1900. But the new psychology missed crucial aspects of mind: the role of conscious cognition (Cs) and at least three kinds of unconscious (Ucs) brain computations: we can call them cognitive, Freudian and Jungian. Each brain process can emerge derivatively in fleeting consciousness, in a long dialogue between Cs and Ucs processes – or sometimes in fringe experiences (James, 1890; Mangan, 2000). In the face of greater challenges, fleeting, serial, and limited capacity Cs/Ucs streams emerge in recurrences over time (Baars, 1988; Baars et al, 2013).

Penfield thought that “cortex is the organ of mind” based on 1,200 surgeries in conscious, intractable epileptics. Waking surgeries have been revived, with over 2,000 new articles. This vast wellspring of evidence began to be better understood in the last half century.

The state of waking consciousness is robust in the face of extensive damage. This image below shows an MRI of a 7 year old Turkish girl after left hemispherectomy for encephalitis. She is bilingual, apparently very functional, and compensates for a blind right hemifield. (Borgstein & Grootendorst, 2002). Some patients remain conscious during surgery for hemispherectomy. Note that the brainstem is intact. Cortex supports conscious contents, while brainstem is needed for conscious states.

Cortex adapts to psycho-physiological injury. The earlier that anomalous deviations occur in development, the more healing adaptations can intervene (Edelman and Tononi, 2000). In rare cases of altered early developmental disorder, as in anencephaly, the visible cortex seems to visibly disappear from its normal cranial space, which is taken over by cerebrospinal fluid. This makes it seem as if the newborn (and later) brain can be conscious without a cortex (Bjorn Merker, 2007).

This important discovery, in the light of G. M. Edelman’s Neural Darwinism, has a plausible explanation: the “missing cortex” comes from an unusual, functional, developmental trajectory. Today’s “neuroscopes” show that many Cs/Ucs functions are performed by the cortex, our first brain region for learning.

In 2008, Eugene Izhikevich and Gerald Edelman made a 3D animation based on all available neuronal evidence from many species.

We view and discuss this 3D animation in our first video lesson. This model is viable due to cross-species similarities. Active neuronal signaling in cortex includes both neural spiking and mass action waves. These findings suggest a new understanding of conscious and unconscious cortex.

Much evidence shows that cortex is the “organ of mind”, as Penfield found over 30 years of waking surgeries. These ideas have been presented by Baars and colleagues. Global Workspace Theory (GWT) has grown into Global Workspace Dynamics (GWD) to incorporate decades of new insights, particularly about the waking cortex. Penfield surgeries gave the best early evidence that conscious cognition crucially involves cerebral cortex.

Cortex is the most hyper-adaptable region of the brain, and reflects evolutionary, ontogenetic, epigenetic, and consciously-mediated learning and adaptation. The story of conscious cognition is the story of cortex in dialogue with unconscious cortico-thalamic and extra-cortical functions.