Global Workspace Theory (GWT) and Prefrontal Cortex: Recent Developments

Baars, Bernard J.; Geld, Natalie; Kozma, Róbert

doi:10.3389/fpsyg.2021.749868

Cited by 38 publications

(14 citation statements)

References 30 publications

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“…3C), around which time activity also abruptly changes in parietal cortex 59 . Such activations may reflect the spontaneous ignition of global activity patterns following threshold-crossings 17,60,61 . Future modeling work could investigate this by directly implementing a threshold mechanism and by recreating the activity of not just slow-ramping neurons but also those with a "step-like" response profile.…”

Section: Future Directionsmentioning

confidence: 99%

Slow ramping emerges from spontaneous fluctuations in spiking neural networks

Gavenas

Rutishauser

Schurger

et al. 2023

Preprint

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The capacity to initiate actions endogenously is critical for goal-directed behavior. Spontaneous voluntary actions are typically preceded by slow-ramping medial frontal cortex activity that begins around two seconds before movement, which may reflect spontaneous fluctuations that influence action timing. However, the mechanisms by which these slow ramping signals emerge from single-neuron and network dynamics remain poorly understood. Here, we developed a spiking neural network model that produces spontaneous slow ramping activity in single neurons and population activity with onsets ∼2 seconds before threshold crossings. A key prediction of our model is that neurons that ramp together have correlated firing patterns before ramping onset. We confirmed this model-derived hypothesis in a dataset of human single neuron recordings from medial frontal cortex. Our results suggest that slow ramping signals reflect bounded spontaneous fluctuations that emerge from quasi-winner-take-all dynamics in clustered networks that are temporally stabilized by slow-acting synapses.HighlightsWe reveal a mechanism for slow-ramping signals before spontaneous voluntary movements.Slow synapses stabilize spontaneous fluctuations in spiking neural network.We validate model predictions in human frontal cortical single neuron recordingsThe model recreates the readiness potential in an EEG proxy signal.Neurons that ramp together had correlated activity before ramping onset.

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Section: Future Directionsmentioning

confidence: 99%

Slow ramping emerges from spontaneous fluctuations in spiking neural networks

Gavenas

Rutishauser

Schurger

et al. 2023

Preprint

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“…According to the main claim of the global workspace theory, a piece of information becomes conscious when it gets into the global workspace (Baars et al, 2021;Mashour et al, 2020;Baars, 1988Baars, , 1998Dehaene et al, 1998). This idea is often further explained by invoking other terms like global availability and cognitive access: the information that is in the global workspace is widely available to many local processors (Mashour et al, 2020) including cognitive systems like planning, reasoning and rational control of action (Block, 2005) that can access, monitor and manipulate this information, and this global broadcasting promotes conscious phenomenology (Block, 2023).…”

Section: Global Workpace Theorymentioning

confidence: 99%

A construct-first approach to consciousness science

Fazekas,

Cleeremans,

Overgaard

2023

Preprint

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We propose a new approach to consciousness science that instead of comparing complex theoretical positions deconstructs existing theories, takes their core assumptions while disregarding their auxiliary hypotheses, and focuses its investigations on the main constructs that these core assumptions rely on (like global workspace, recurrent processing, metarepresentation). Studying how these main constructs are anchored in lower-level constructs characterizing underlying neural processing will not just offer an alternative to theory comparisons but will also take us one step closer to empirical resolutions. Moreover, exploring the compatibility and possible combinations of the lower-level constructs will allow for new theoretical syntheses. This construct-first approach will improve our ability to understand the commitments of existing theories and pave the way for moving beyond them.

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“…Cognitive scientist Bernard J. Baars first proposed the GWT in 1983. GWT is a cognitive architecture inspired by artificial intelligence where a centralized resource is available through which specialized processors share and receive information ( Baars, 2005 ; Baars et al, 2021 ). The theory is based on the observation that there are highly specialized brain regions that process information locally and unconsciously, such as the visual cortex.…”

Section: Physicalist Theories Of Consciousnessmentioning

confidence: 99%

What if consciousness is not an emergent property of the brain? Observational and empirical challenges to materialistic models

Wahbeh

Radin²,

Cannard³

et al. 2022

Front. Psychol.

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The nature of consciousness is considered one of science’s most perplexing and persistent mysteries. We all know the subjective experience of consciousness, but where does it arise? What is its purpose? What are its full capacities? The assumption within today’s neuroscience is that all aspects of consciousness arise solely from interactions among neurons in the brain. However, the origin and mechanisms of qualia (i.e., subjective or phenomenological experience) are not understood. David Chalmers coined the term “the hard problem” to describe the difficulties in elucidating the origins of subjectivity from the point of view of reductive materialism. We propose that the hard problem arises because one or more assumptions within a materialistic worldview are either wrong or incomplete. If consciousness entails more than the activity of neurons, then we can contemplate new ways of thinking about the hard problem. This review examines phenomena that apparently contradict the notion that consciousness is exclusively dependent on brain activity, including phenomena where consciousness appears to extend beyond the physical brain and body in both space and time. The mechanisms underlying these “non-local” properties are vaguely suggestive of quantum entanglement in physics, but how such effects might manifest remains highly speculative. The existence of these non-local effects appears to support the proposal that post-materialistic models of consciousness may be required to break the conceptual impasse presented by the hard problem of consciousness.

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Global Workspace Theory (GWT) and Prefrontal Cortex: Recent Developments

Cited by 38 publications

References 30 publications

Slow ramping emerges from spontaneous fluctuations in spiking neural networks

Slow ramping emerges from spontaneous fluctuations in spiking neural networks

A construct-first approach to consciousness science

What if consciousness is not an emergent property of the brain? Observational and empirical challenges to materialistic models

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