Head to head
Functionalism vs Attention Schema Theory
Functionalism and Attention Schema Theory, compared field by field from their entries in the Atlas.
At a glance
- Both belong to the Materialism family in Kuhn's Landscape of Consciousness.
- Both treat consciousness as emergent.
- They give the same kind of answer on AI consciousness and meaning and purpose.
- On life after death, Functionalism says “Conditional” and Attention Schema Theory says “No”.
- On mind uploading, Functionalism says “Likely” and Attention Schema Theory says “Possible”.
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The claim
In brief
FunctionalismFunctionalism posits that mental states are defined by their causal relations to one another, to sensory inputs, and to behavioral outputs, independent of the physical medium (substrate) in which they are realized. The essence of consciousness is determined by how mental states function or operate, rather than by what they are materially composed of.
Attention Schema TheoryThis theory posits that consciousness arises when the brain constructs a quick, simplified, internal model—an attention schema—of its own process of attention. The brain mistakenly interprets and reports this internal representation as a subjective, non-physical essence or a 'self-caricature,' even though it is fundamentally a computational product.
What consciousness is
FunctionalismMental states are identified as functional states, constituted by their causal relations, roles, results, and outputs, implying they are realizable in any substrate that supports those functions.
Attention Schema TheoryConsciousness is identified as the brain’s internal representation or simplified model of its own mechanism of attention (the attention schema), which is a specific example of higher-order thought.
Big questions
Can AI be conscious?Both agree
FunctionalismYesFunctionalism holds that consciousness is based on function, not biology. If the correct functions can be realized computationally in non-biological substrates, AI consciousness is possible in principle and certain if Materialism is true.
Attention Schema TheoryLikelySince consciousness is defined as a computational process (the creation of an attention schema), in principle, artificial systems that implement the necessary computational architecture could become conscious. Furthermore, observers will inevitably make the social attribution of consciousness to sufficiently complex AI systems that act like they are conscious.
FunctionalismConditionalAs a physicalist theory, consciousness is tied to the substrate. Survival beyond death of the biological body is only possible if the functional mental state can be successfully transferred (uploaded) to a new, continuing substrate (virtual immortality).
Attention Schema TheoryNoAs a Materialist/Neurobiological theory, consciousness is tied to the physical substrate (the biological, information-processing machine), precluding survival beyond the decay of the body.
FunctionalismLikelyFunctionalism serves as the theoretical basis for virtual immortality. If the functional role of the mental self can be perfectly duplicated and uploaded to a new medium, the first-person mental self is preserved.
Attention Schema TheoryPossibleIf the consciousness is realized as a computational structure (the attention schema), and if this structure and the relevant information processing systems can be accurately uploaded to a non-biological medium, virtual immortality is theoretically possible.
Does it give life meaning?Both agree
FunctionalismHumanistic onlyFunctionalism describes the mechanism by which mind/consciousness operates within a physical world, providing capacities for agency and reflection, but offers no rationale for ultimate cosmic meaning or teleology, aligning with the general stance of Materialism.
Attention Schema TheoryHumanistic onlyConsciousness provides an adaptive, evolutionary purpose (monitoring and regulating attention for action control), but does not imply any ultimate or cosmic meaning, consistent with Materialism.
Nature of mind
Ontology
FunctionalismPhysicalism (broadly, agnostic to substance). The theory is classified under Materialism, but it is metaphysically agnostic regarding nonphysical substances, focusing primarily on the functional description of mental states.
Attention Schema TheoryPhysicalism
Mind and body
FunctionalismMental states are functional states identical to the functional roles that are realized or instantiated in a physical substrate, leading to 'functional state identity theses'.
Attention Schema TheoryConsciousness is the report generated by a biological, information processing machine (the brain) through the assessment of its internal data, meaning mental states are computational and wholly physical.
Fundamental or emergent
FunctionalismEmergent. Consciousness arises from the functional organization realized by a sufficiently complex substrate (like neural tissue or computer chips).
Attention Schema TheoryEmergent
Qualia
FunctionalismThe theory traditionally struggles to account for phenomenal qualia, often addressing them by asserting that the qualitative feel is entirely exhausted by the functional role, or by coupling with representational theories.
Attention Schema TheoryConsciousness is described as a 'self-caricature' or an illusory report of a non-physical essence, suggesting a deflationary or illusionist account of qualia, akin to Daniel Dennett’s view.
How it works
Mechanism
FunctionalismThe principle of multiple realizability, stating that mental state realization is independent of the physical substrate, contingent only upon the required function being instantiated.
Attention Schema TheoryThe construction and maintenance of a simplified internal model (the attention schema) of the process of attention, rooted in principles from control engineering.
Where it is
FunctionalismDistributed wherever the functional organization is successfully realized, regardless of whether the substrate is neural tissue or hardwired computing components.
Attention Schema TheoryLocated within the biological, information-processing system of the brain.
What it does
FunctionalismFunctions, roles, and outputs are dispositive. Mental states are causally effective because they are defined by their causal relations within the system (functional role).
Attention Schema TheoryThe functional role of the attention schema is to monitor and regulate the brain's attention in order to control actions in the world. The resulting capacity allows the system to claim consciousness.
Evidence and criticism
Testability
FunctionalismConceptually and empirically testable. Thought experiments (like substrate replacement) probe its conceptual limits, and computational realization (AI) tests its empirical application.
Attention Schema TheoryEmpirically testable
Tests so far
FunctionalismThe silicon chip replacement thought experiment is used conceptually to test whether phenomenal consciousness is preserved when the functional role is maintained across a change in substrate.
Attention Schema TheoryNot stated
Criticisms
FunctionalismIt is criticized heavily for failing to account for phenomenal consciousness (qualia) by describing only the functional role, leading to the 'hard problem' challenge that functional roles may not exhaust the nature of conscious experience.
Attention Schema TheoryThe theory explains how a system can *claim* consciousness but faces the general limitation, shared by similar functionalist models, of conclusively proving or explaining the actual subjective feel (the 'anybody home' problem) which remains eternally uncertain, even by the proponent's admission.
Sources
Key sources
Functionalism
- What is functionalism? (N. Block) (1980)
- What Is Functionalism? Consciousness, Function, and Representation (N. Block) (2007)
- Functionalism (J. Levin) (2023)
Attention Schema Theory
- True nature of consciousness: solving the biggest mystery of your mind, M. Graziano (2019)
- Rethinking Consciousness: A Scientific Theory of Subjective Experience, M. Graziano (2019)
- Can consciousness be non-biological?, M. Graziano (2014)