Recently, we looked at the Integrated information theory (IIT) of human consciousness, as defined by the renowned neuroscientist at the Allen Institute Christof Koch. Another prominent competitor (and rival) is Global Workspace Theory (GWT) – it represents the brain as an orchestra with many conductors.

IIT is panpsychist oriented (the universe participates in consciousness; human consciousness is the most developed instance) while GWT uses information theory to capture an image of consciousness via observations of the brain at work.

A recent essay in Psyche by two promoters of GWT, Morten L. Kringelbach and Gustav Deco, presents to us to GWT:

… Given the distributed nature of the brain hierarchy, it is unlikely that there is only one “conductor”. Instead, in 1988, psychologist Bernard Baars proposed the concept of a “global workspace,” where information is integrated into a small group of brain regions (or “conductors”) before being distributed to the whole brain …

Colloquially, the brain’s global workspace is thus akin to a small nucleus of people in charge of an organization: like a group of Herbert von Karajans conducting a musical orchestra.

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

Oxford neuroscientist Morten L Kringelbach is the author of Emotion: Pain and pleasure in the brain (2014), co-authored with Helen Phillips. Gustavo Deco, director of the Brain and Cognition Center of Barcelona, ​​is the author of The noisy brain (2010), co-authored with Edmund T Rolls. Together, Kringelbach and Deco published a paper this year in Nature Human Behavior, in which they identified the brain regions of 1000 participants that they assume to be a “global workspace” (the “functional rich club”) of conductors:

This very famous theory offered an elegant solution to the problem of how hierarchical organization allows the brain to orchestrate function and behavior by organizing the flow of information and the underlying calculations necessary for survival. As such, it is a theory of consciousness, as emphasized by neuroscientists Stanislas Dehaene, Michael Kerszberg and Jean-Pierre Changeux, who in 1998 proposed their modification: the workspace hypothesis. global neural, where associative perceptual, motor, attention, memory, and value areas interconnect to form a unified upper-level space in which information is widely shared and rebroadcast to lower-level processors. Colloquially, the brain’s global workspace is thus akin to a small nucleus of people in charge of an organization: like a group of Herbert von Karajans conducting a musical orchestra.

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

In their model, at a high level, the brain conductors merge information from the senses with memories. Treatment “is further influenced by reward and expectations and any surprising deviations from previous experiences.”

Much progress has been made in understanding the anatomical wiring of the brain. But here’s the riddle. This is not essential for the flow of information:

This research has provided important information about the anatomical hierarchy of the brain. At the same time, each region of the brain has a different and specific local dynamic, giving rise to the unconstrained nature of the flow of functional information, which is thus shaped but not entirely determined by the underlying anatomy. What ultimately matters in determining the orchestration of brain function are the dynamic changes in the flow of functional information.

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

A moment earlier, the authors had pointed out,

The flow of information within this hierarchy is very dynamic; not only from bottom to top but also from top to bottom. In fact, the recurring interactions shape the functional processing underlying cognition and behavior. Much of this information flow follows the underlying anatomy in the structural connections between regions of the brain, but also the information flow is largely unconstrained by this anatomical wiring.

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

Well, if the flow of information in the brain is “largely unconstrained” by anatomical wiring, it’s easy to see why we feel we have “spirits” outside of our brains.

Global Workspace theorists decided to take an information theory approach to the problem: shown to causally influence activity in another. Ultimately, the framework was able to provide us with the flow of information between all regions of the brain, which in turn allowed us to study functional hierarchical organization and how it relates to anatomy. This is where their concept of a “functional rich club” or FRIC (a French word for money) comes in: “a dynamic measurement based on a two-way flow of information not constrained by anatomy and thus evolving between different tasks. “:

To use our old metaphor of orchestral music, the main role of “conductor” is assumed by a group of different musicians serving as “hubs”. Some of these musicians will remain conductors, regardless of the type of concert, just as the different sections of a real orchestra retain the first violinist and the first cellist. (In reality, the conductor is seldom chosen from among the existing musicians within a real orchestra. However, the brain economy is such that it cannot afford to call upon a von Karajan as general conductor of everything.)

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

Wait. Why can’t the brain “afford” a von Karajan-type conductor? ? Isn’t the point rather that the brain doesn’t need him? If GWT is a good theory, a result is that there is no “point of consciousness” in the brain. Finding the point of consciousness in 25 years was the basis of a scientific bet of 1998 between two famous personalities in the studies of consciousness (Christof Koch and David Chalmers) and he only has two years left to run …

The GWT researchers are careful to point out that they perceive the relationship between the parts of the brain they believe responsible for consciousness as “mechanistic”:

Using this method, we discovered that the overall workspace consists of a central subset of brain regions, which include the precuneus, posterior and cingulate isthmus, nucleus accumbens, putamen, hippocampus and amygdala (see figure below). This basic functional “club” of integrative brain regions is consistent with the original proposition of Dehaene, Kerszberg and Changeux, which suggests that the global neural workspace must integrate past and present through focus and evaluation.

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

But then they also relate,

We have shown that lesion of regions of the global workspace in the whole brain model significantly impairs the brain’s ability to function. However, we have also shown that the brain is like a multi-headed hydra that can still function with one or two severed heads. It demonstrates the robustness and resilience of the human brain in the face of adversity, and the ways in which conductors can take on additional responsibilities when necessary.

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

It’s not very mechanical, really. They then invoke, ending self-organization theory:

A direct consequence of our new discovery is that it is now clear that the immense chaos occurring in complex systems can be carefully orchestrated by a small subset of “conductors”, self-organizing from the constituent parts. Unlike musical orchestras which are greatly enhanced by a brilliant von Karajan, the great resilience of the orchestration of the brain is that it relies on the concerted efforts of a small subset of agile and adaptable conductors in its overall workspace. .

Morten L Kringelbach and Gustavo Deco, “The brain has a team of conductors who orchestrate consciousness” To Psyche (October 6, 2021)

A reader may find the authors’ model curious: a team of conductors is much more complex than an imposing von Karajan. The fact that such a system can emerge – loaded with excellent opportunities for decisive early failure – is, in itself, remarkable. However, their decision to rely on information theory as a source of models seems wise.

In 2019, Templeton World Charities ran a competition, of sorts, between Global Workspace Theory (GWT) and Integrated information theory (IIT) although the COVID-19[female[feminine the pandemic seems to have delayed it somewhat. It will certainly be one to watch.

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You can also read: Fast facts on IIT, the main theory of consciousness (if not related to the theory of the global workspace). IIT may be part of a scientific trend in which emerging and panpsychistic theories are slowly replacing materialist and physicalist theories. Note that GWT is also not very firmly tied to mechanism or materialism.

Also: A theoretical physicist grapples with the mathematics of consciousness. Sabine Hossenfelder is not very happy with what she sees. Even for a worm’s brain, the best proposed theory would take billions of years to calculate, she said. This cannot be the correct answer.