Attention schema theory
Explanation
Michael Graziano, neuroscientist at Princeton, proposed in Consciousness and the Social Brain (2013) the Attention Schema Theory (AST): consciousness is the simplified model the brain generates of its own attention processes, analogous to the simplified model it generates of the body (the body schema). We need not know all the mechanical details of a process to monitor and control it: a schematic model is sufficient and efficient.
The key analogy is with the body schema. The brain has a model of where its arms, legs and orientation in space are. This model is schematic (it does not represent every muscle or every joint in detail) but useful: it allows movements to be coordinated, actions planned, and even rubber-hand illusions to be experienced. Analogously, the attention schema would be a simplified model of which processes the brain is attending to at any given moment.
Subjective consciousness, according to Graziano, is how this attention schema presents itself internally: as conscious experience, with its apparently immaterial qualities. Just as the body schema produces the vivid sensation of having a physical body even though it is a model, the attention schema produces the vivid sensation of having a conscious mind even though it is a model.
A theoretical advantage of AST is that it directly addresses the meta-cognitive problem: why do humans believe they have immaterial subjective consciousness? Because their attention schema describes their own attention in non-mechanical terms, as experience, qualia, etc. Verbal reports about consciousness would be outputs of that schema, not direct descriptions of the underlying physical processes.
Graziano proposes a clear evolutionary function: the attention schema makes it possible to predict one's own attention (what I will do next) and, by extension through social cognition, the attention of others (what the other will do). This improves coordination, cooperation, competitive strategy. Consciousness would not be a useless epiphenomenon, but a useful tool for modelling behaviour.
The theory has received criticism: some consider that it reduces consciousness to a cognitive epiphenomenon without addressing the hard problem; others argue that it is vague about exact neural mechanisms. But it has gained traction as a proposal that combines functionalism, computational neuroscience and analytic philosophy, and connects phenomena such as social cognition, theory of mind and introspection under a single explanatory umbrella.
Strengths
- Integrates findings on attention and meta-cognition.
- Neurally plausible mechanism.
- Explains why consciousness seems mysterious (a simplified model).
- Transferable to AI.
Main critiques
- Does not explain qualia: that the brain models its attention does not entail experience.
- The 'simplified model' argument can be applied to any property: it trivialises.
- Insufficient articulation with more detailed theories (IIT, GNW).
- Critique from the hard problem: it explains the function, not the experience.