The Spontaneous Brain
September 14, 2018
Georg Northoff
This chapter examines whether the spectrum model of the brain, which posits that stimulus-induced activity has a hybrid nature, is relevant to consciousness. The author reviews empirical evidence from disorders of consciousness, including vegetative state, anesthesia, and sleep. These findings suggest that loss of consciousness in these conditions is characterized by a shift in stimulus-induced activity toward the passive pole, losing its hybrid nature. The author proposes that the hybrid nature of stimulus-induced activity, including its spatiotemporal integration as described in the spectrum model, is central to the level of consciousness. Consequently, the author concludes the spectrum model is relevant for consciousness.
The Spontaneous Brain
September 14, 2018
Georg Northoff
Predictive coding, which explains brain activity as the interaction between predicted and actual sensory inputs, can account for which contents are selected for consciousness and whether those contents are accurate or inaccurate. However, it cannot explain why any particular content is associated with consciousness itself. Consciousness extends beyond its contents and our cognition of them, so the prediction model of the brain cannot serve as a full cognitive model of consciousness.
The Spontaneous Brain
September 14, 2018
Georg Northoff
The world is indispensable for consciousness: without it, the world-brain relation that makes consciousness possible cannot exist. Three arguments support this claim. The "argument of calibration" holds that the world provides a spatiotemporal frame that calibrates possible experiences and yields phenomenal features. The "argument of structure" shows that the world's spatiotemporal nestedness—the brain contained within the world's larger scale—predisposes consciousness. The "argument of location" distinguishes complex location (brain and consciousness as part of the world) from simple or non-location. Including both world and brain in the ontology of consciousness, as the "world-brain problem," is necessary; reducing consciousness to brain or world alone leaves an explanatory gap.
The Spontaneous Brain
September 14, 2018
Georg Northoff
The chapter presents an interaction model of brain activity to characterize neural correlates of consciousness. Empirical evidence from disorders of consciousness, anesthesia, and sleep shows that the degree of non-additive interaction between spontaneous and stimulus-induced activity indexes the level of consciousness in a fine-grained way, making it a neural correlate of consciousness (NCC). In contrast, spontaneous activity and its spatiotemporal structure are a necessary condition for possible consciousness, termed a neural predisposition of consciousness (NPC). Drawing on Nancy Cartwright's concept of capacities, the author argues that the brain's non-additive interaction underlying consciousness depends on the spontaneous activity's capacity, which is traceable to its spatiotemporal features—a "spatiotemporal capacity." The data suggest a capacity-based rather than law-based approach to understanding the brain-consciousness relationship.
The Spontaneous Brain
September 14, 2018
Georg Northoff
Consciousness is ontologically grounded in the world-brain relation, a spatiotemporal structure that provides the necessary but not sufficient condition for phenomenal experience. The author argues that the world-brain relation, characterized by relational time and space, enables an 'upward spatiotemporal entailment' of consciousness, establishing a necessary a posteriori connection between brain and consciousness without invoking a separate concept of mind. This approach, based on ontic structural realism, dissolves the traditional mind-body problem, replacing it with a 'world-brain problem' where mental features are understood as ontologically continuous with the world-brain relation rather than requiring an additional mental substance.