Computational modelling shows evidence in support of both sensory and frontal theories of consciousness
Kavindu H. Bandara, Elise G. Rowe, Marta I. Garrido
bioRxiv Preprint Server November 2, 2024 preprint DOI: 10.1101/2024.11.02.621640 via bioRxiv
Summary
The prefrontal cortex's role in consciousness is debated: frontal theories say it is necessary, while sensory theories argue consciousness arises from the posterior cortex alone. Re-analyzing EEG data from 30 participants in a no-report inattentional blindness paradigm, dynamic causal modeling estimated effective connectivity between prefrontal and posterior cortices. A data-driven search could not support either theory, but a hypothesis-driven analysis showed both could explain the data, with a slight preference for frontal theories. A model disabling backward connections within the posterior cortex explained awareness better (53%) than one without prefrontal-to-sensory backward connections. The findings suggest a subtle frontal contribution and call for revising current theories.
Study at a glance
| Characteristics | Observational study with re-analysis of EEG data |
|---|---|
| Sample size | 30 |
| Population | Human participants in a no-report inattentional blindness paradigm |
| Key finding | A hypothesis-driven analysis showed that both frontal and sensory theories could explain the data, with a model disabling backward connections within the posterior cortex explaining awareness better (53%) than one without prefrontal-to-sensory backward connections, providing slight support for frontal theories. |
Abstract
The role of the prefrontal cortex (PFC) in consciousness is hotly debated. Frontal theories argue that the PFC is necessary for consciousness, while sensory theories propose that consciousness arises from recurrent activity in the posterior cortex alone, with activity in the PFC resulting from the mere act of reporting. To resolve this dispute, we re-analysed an EEG dataset of 30 participants from a no-report inattentional blindness paradigm where faces are (un)consciously perceived. Dynamic causal modelling was used to estimate the effective connectivity between the key contended brain regions, the prefrontal and the posterior cortices. Then, a second-level parametric empirical Bayesian model was conducted to determine how connectivity was modulated by awareness and task-relevance. While an initial data-driven search could not corroborate neither sensory nor frontal theories of consciousness, a more directed hypothesis-driven analysis revealed strong evidence that both theories could explain the data, with a very slight preference for frontal theories. Specifically, a model with backward connections switched off within the posterior cortex explained awareness better (53%) than a model without backward connections from the PFC to sensory regions. Our findings provide some support for a subtle, yet crucial, contribution of the frontal cortex in consciousness, and highlight the need to revise current theories of consciousness.