“I think in terms of consciousness, it seems to me that these Feelings of Knowing are perhaps the conscious tip of the iceberg for this huge amount of unconscious processing that’s going on of all this information in our environment, where maybe I couldn’t tell you why I know there’s danger, but I know.“

– Alea Skwara, postdoctoral scholar at the UC Davis Center for Mind and Brain and Global Migration Center

Episode 17 is the second in a three-part series on GWT Origins & Evidence, featuring our student interviewers, Alea Skwara and Ilian Daskalov. Together with Bernard Baars, they examine the recent neuroscientific study of consciousness.

After some quick introductions, Alea briefly summarizes their discussion in Part I on the history of Global Workspace, how the theory evolved, as well as some of the core hypotheses it generates. Now we dive into the brain evidence.

Global Workspace Theory (or GWT) was first formulated in the ‘80s as a psychological theory of how consciousness might operate. In Part I, we talked about the spotlight metaphor. One of the key predictions of GWT is “widespread integration and broadcasting.” This seems to be one of the predictions that can be most directly tested by brain activity, our topic today.

Cortical Binding and Propagation

The trio delves into the first of 4 papers, namely Baars’ 2013 paper called “Global Workspace Dynamics.” This paper comes as the result of four decades of cumulative work, which pulls together the evidence as of 2013. One of its key points connecting GWT to neuroscientific evidence is that GWT does not require (or suggest) an “anatomical hub” of coordinated activity, but, instead, a momentary, dynamic “functional hub.”

Bernie, Alea and Ilian explore the question: What is the difference between an anatomical hub and a functional hub, and what does it mean to say that a functional hub is dynamic?

Bernie explains how the conscious brain is characterized by ‘widespread integration and broadcasting.’ The cortex is like a large city with specialized neighborhoods, streets and alleys. There is an ever changing flow of traffic between them. He then suggests that the thalamus is more than a relay station of the brain, and that the sensory thalamus is an entryway to the giant cortico-thalamic (CT) system, which integrates and broadcasts conscious information.

Next, Ilian asks how we can experimentally test conscious processes. This moves the conversation to Feelings of Knowing (FOKs), which is one fundamental type of conscious experience. Bernie makes the point that Feelings of Knowing are an integral part of the conscious stream.

To listen to the full episode, CLICK HERE!

• Twitter
• Facebook
• Digg
• Evernote
• Pinterest

 

Talking Points:

• 0:00 – Intro

• 5:24 – History of Global Workspace Theory

• 8:23 – Discussion Paper #1: Baars et al. (2013) Global Workspace Dynamics

• 9:32 – What is meant by “Widespread Integration?”

• 17:22 – The Neuroscience of Widespread Integration

• 25:26 – Corticothalamic Loops in Relation to GWT

• 30:10 – Localist vs Local-Global Theories

• 35:46 – “The Question of Introspection”

• 43:01 – How is Consciousness Assessed?

• 49:58 – Feelings of Knowing (FOKs)

• 54:33 – Discussion Paper #2: Gaillard et al. (2009) Converging Intracranial Markers…

• 1:04:20 – Discussion Paper #3: Herman et al. (2019) A Switch & Wave of Neuronal Activity

• 1:14:55 – Brain Oscillations: Gamma and Beta Bands

• 1:20:56 – Paper #4: Deco et al. (2021) Revisiting the Global Workspace

• 1:26:29 – Functional Rich Clubs

• 1:41:50 – The Future Quest for Consciousness

Links to Papers Discussed in the Episode

Paper 1: “Global Workspace Dynamics: Cortical ‘Binding and Propagation’ Enables Conscious Contents

Paper 2: Converging Intracranial Markers of Conscious Access

Paper 3: A Switch and Wave of Neuronal Activity in the Cerebral Cortex During the First Second of Conscious Perception

Paper 4: Revisiting the Global Workspace: Orchestration of the Functional Hierarchical Organisation of the Human Brain

Bios

Alea Skwara is now a postdoctoral scholar at the UC Davis Center for Mind and Brain and Global Migration Center. Her research explores the neurocognitive bases of compassion and adaptive responses to suffering, and how we can bridge basic research and urgent real-world issues to create a more just society for all.

Ilian Daskalov is a senior undergraduate student at University of California, Irvine where he studies Cognitive Science. His research interests include sleep, psychedelics, and artificial intelligence and he is passionate about communicating science and promoting critical thinking.

Global Workspace Theory (GWT) began with this question: “How does a serial, integrated and very limited stream of consciousness emerge from a nervous system that is mostly unconscious, distributed, parallel and of enormous capacity?”

GWT is a widely used framework for the role of conscious and unconscious experiences in the functioning of the brain, as Baars first suggested in 1983.

A set of explicit assumptions that can be tested, as many of them have been. These updated works by Bernie Baars, the recipient of the 2019 Hermann von Helmholtz Life Contribution Award by International Neural Network Society form a coherent effort to organize a large and growing body of scientific evidence about conscious brains.