Graziano, the Attention Schema Theory, and the Neuroscientific Explananda Problem

by rsbakker

Along with Taylor Webb, Michael Graziano has published an updated version of what used to be his Attention Schema Theory of Consciousness, but is now called the Attention Schema Theory of Subjective Awareness. For me, it epitomizes the kinds of theoretical difficulties neuroscientists face in their attempts to define their explananda, why, as Gary Marcus and Jeremy Freeman note in their Preface to The Future of the Brain, “[a]t present, neuroscience is a collection of facts, still awaiting an overarching theory” (xi).

On Blind Brain Theory, the ‘neuroscientific explananda problem’ is at least twofold. For one, the behavioural nature of cognitive functions raises a panoply of interpretative issues. Ask any sociologist: finding consensus commanding descriptions of human behaviour is far more difficult than finding consensus commanding descriptions of, say, organ behaviour. For another, the low-dimensional nature of  conscious experience raises a myriad of interpretative conundrums in addition to the problems of interpretative underdetermination facing behaviour.  Ask any psychologist: finding consensus commanding descriptions of conscious phenomena has hitherto proven impossible. As William Uttal notes in The New Phrenology: “There is probably nothing that divides psychologists of all stripes, more than the inadequacies and ambiguities of our efforts to define mind, consciousness, and the enormous variety of mental events and phenomena” (90). At least with behaviour, publicity allows us to anchor our theoretical interpretations in revisable data; experience, however, famously affords us no such luxury. So where the problem of behavioural underdetermination seems potentially soluble given enough elbow grease (one can imagine continued research honing canonical categorizations of behavioural functions as more and more information is accumulated), the problem of experiential underdetermination out and out baffles. We scarce know where to begin. Some see conscious experience as a natural phenomena possessing properties that do not square with our present scientific understanding of nature. Others, like myself, see conscious experience as a natural phenomena that only seems to possess properties that do not square with our nature. Michael Graziano belongs to this camp also. The great virtue of belonging to this deflationary pole of the experiential explananda debate is that it spares you the task of explaining inexplicable entities, or the indignity of finding rhetorical ways to transform manifest theoretical vices (like analytic opacity) into virtues (like ‘irreducibility’). In other words, it lets you drastically simplify the explanatory landscape. Despite this, Graziano’s latest presentation of his theory of consciousness (coauthored with Taylor Webb), “The attention schema theory: a mechanistic account of subjective awareness,” seems to be deeply–perhaps even fatally–mired in the neuroscientific explananda problem.

Very little in Webb and Graziano’s introduction to AST indicates the degree to which the theory has changed since the 2013 publication of Consciousness and The Social Brain. The core insight of Attention Schema Theory is presented in the same terms, the notion that subjective awareness, far from being a property perceived, is actually a neural construct, a tool the human brain uses to understand and manipulate both other brains and itself.  They write:

This view that the problem of subjective experience consists only in explaining why and how the brain concludes that it contains an apparently non-physical property, has been proposed before (Dennett, 1991). The attention schema theory goes beyond this idea in providing a specific functional use for the brain to compute that type of information. The heart of the attention schema theory is that there is an adaptive value for a brain to build the construct of awareness: it serves as a model of attention. 2

They provide the example of visual attention upon an apple, how the brain requires, as a means to conclude it was ‘subjectively aware’ of the apple, information regarding itself and its means of relating to the apple. This ‘means of relating’ happens to be the machinery of attention, resulting in the attention schema, a low-dimensional representation of the high-dimensional complexities comprising things like visual attention upon an apple. And this, Graziano maintains, is what ‘subjective awareness’ ultimately amounts to: “the brain’s internal model of the process of attention” (1).

And this is where the confusion begins, as much for Webb and Graziano as for myself. For one, ‘consciousness’ has vanished from the title of the theory, replaced by the equally overdetermined ‘subjective awareness.’ For another, the bald claims that consciousness is simply a delusion have all but vanished. As recently as last year, Graziano wrote:

How does the brain go beyond processing information to become subjectively aware of information? The answer is: It doesn’t. The brain has arrived at a conclusion that is not correct. When we introspect and seem to find that ghostly thing — awareness, consciousness, the way green looks or pain feels — our cognitive machinery is accessing internal models and those models are providing information that is wrong. The machinery is computing an elaborate story about a magical-seeming property. And there is no way for the brain to determine through introspection that the story is wrong, because introspection always accesses the same incorrect information. “Are We Really Conscious,” The New York Times Sunday Review.

Here there simply is no such thing as subjective awareness: it’s a kind of cognitive illusion foisted on the brain by the low-dimensionality of the attention schema. Now, however, the status of subjective awareness is far less clear. Webb and Graziano provide the same blind brain explanation (down to the metaphors, no less) for the peculiar properties apparently characterizing subjective awareness: since the brain has no use for high-dimensional information, the “model would be more like a cartoon sketch that depicts the most important, and useful aspects of attention, without representing any of the mechanistic details that make attention actually happen” (2). As a result of this opportunistic simplification, it makes sense that a brain:

“would conclude that it possesses a phenomenon with all of the most salient aspects of attention – the ability to take mental possession of an object, focus one’s resources on it, and, ultimately, act on it – but without any of the mechanisms that make this process physically possible. It would conclude that it possesses a magical, non-physical essence, but one which can nevertheless act and exert causal control over behavior, a mysterious conclusion indeed.” 2

This is a passage that would strike any long time followers of TPB as a canonical expression of Blind Brain Theory, but there are some key distinctions dividing the two pictures, which I’ll turn to in a moment. For the nonce, it’s worth noting that it’s not so much subjective awareness (consciousness) that now stands charged with deception, as the kinds of impossible properties that attributed to it. Given that subjective awareness is the explicit explanandum, there’s a pretty important ambiguity here between subjective awareness as attention schema and subjective awareness as impossible construct. Even though the latter is clearly a cognitive illusion, the former is real insofar as the attention schema is real.

For its part, Blind Brain Theory is a theory, not of consciousness, but of the appearance of consciousness. It provides a principled way to detect, diagnose and even circumvent the kinds of cognitive illusions the limits of deliberative metacognition inflict upon reflection. It only explains why, given the kind of metacognitive resources our brains actually possess, the problem of consciousness constitutes a ‘crash space,’ a domain where we continually run afoul the heuristic limitations of our tools. So when I reflect upon my sensorium, for instance, even though I am unencumbered by supernatural characterizations of phenomenology—subjective awareness—something very mysterious remains to be explained, it’s just nowhere near so mysterious as someone like, Chalmers, for instance, is inclined to think.

Graziano, on the other hand, thinks he possesses a bona fide theory of consciousness. The attention schema, on his account, is awareness. So when he reflects upon his sensorium, he’s convinced he’s reflecting upon his ‘attention schema,’ that this is the root of what consciousness consists in—somehow.

I say ‘somehow,’ because in no way is it clear why the attention schema, out of all the innumerable schematisms the brain uses to overcome the ‘curse of dimensionality,’ should be the one possessing (the propensity to be duped by?) subjective awareness. In other words, AST basically suffers the same problem all neural identity theories suffer: explaining what makes one set of neural mechanisms ‘aware’ while others remain ‘dark.’ Our brains run afoul their cognitive limitations all the time, turn on countless heuristic schema: why is the attention schema prone to elicit sensoriums and the like?

Note that he has no way of answering, ‘Because that’s how attention is modelled,’ without begging the question. We want to know what makes modelling attention so special as to result in what, mistaken or not, we seem to be enjoying this very moment now. Even though he bills Attention Schema Theory as a ‘mechanistic account of subjective awareness,’ there’s a real sense in which consciousness, or ‘subjective awareness,’ is left entirely unexplained. Why should a neurobiologically instantiated schema of the mechanisms of attention result in this mad hall of mirrors we are sharing (or not) this very moment?

Graziano and Webb have no more clue than anyone. AST provides a limited way to understand the peculiarities of experience, but it really has no way whatsoever of explaining the fact of experience.

He had no such problem with the earlier versions of AST simply because he could write off consciousness as an illusion entirely, as a ‘squirrel in the head.’ Once he had dispatched with the peculiarities of experience, he could slap his pants and go home. But of course, this stranded him with the absurd position of denying the existence of conscious experience altogether.

Now he acknowledges that consciousness exists, going so far as to suggest that AST is consistent with and extends beyond global workspace and information integration accounts.

“The attention schema theory is consistent with these previous proposals, but also goes beyond them. In the attention schema theory, awareness does not arise just because the brain integrates information or settles into a network state, anymore than the perceptual model of color arises just because information in the visual system becomes integrated or settles into a state. Specific information about color must be constructed by the visual system and integrated with other visual information. Just so, in the case of awareness, the construct of awareness must be computed. Then it can be integrated with other information. Then the brain has sufficient information to conclude and report not only, “thing X is red,” or, “thing X is round,” but also, “I am aware of thing X.” 3

If this is the case, then subjective awareness has to be far more than the mere product of neural fiat, a verbal reporting system uttering the terms, “I am aware of X.” And it also has to be far more than simply paying attention to the model of attention. If AST extends beyond global workspace and information integration accounts, then the phenomenon of consciousness exceeds the explanatory scope of AST. Before subjective awareness was a metacognitive figment, the judgment, “I am aware of thing X” exhausted the phenomenology of experiencing X. Now subjective awareness is a matter of integrating the ‘construct of awareness’ (the attention schema) with ‘other information’ to produce the brain’s conclusion of phenomenology.

At the very least, the explanatory target of AST needs to be clarified. Just what is the explanandum of the Attention Schema Theory? And more importantly, how does the account amount to anything more than certain correlations between a vague model and the vague phenomena(lity) it purports to explain?

I actually think it’s quite clear that Graziano has conflated what are ultimately two incompatible insights into the nature of consciousness. The one is simply that consciousness and attention are intimately linked, and the other is that metacognition is necessarily heuristic. Given this conflation, he has confused the explanatory power of the latter as warrant for reducing subjective awareness to the attention schema. The explanatory power of the latter, of course, is simply the explanatory power of Blind Brain Theory, the way heuristic neglect allows us to understand a wide number of impossible properties typically attributed to intentional phenomena. Unlike the original formulation of AST, Blind Brain Theory has always been consilient with global workspace and information integration accounts simply because heuristic neglect says nothing about what consciousness consists in, only the kinds of straits the limits of the human brain impose upon the human brain’s capacity to cognize its own functions. It says a great deal about why we find ourselves still, after thousands of years of reflection and debate, completely stumped by our own nature. It depends on the integrative function of consciousness to be able to explain the kinds of ‘identity effects’ it uses to diagnose various metacognitive illusions, but beyond this, BBT remains agnostic on the nature of consciousness (even as it makes hash of the consciousness we like to think we have).

But even though BBT is consilient with global workspace and information integration accounts the same as AST, it is not consilient with AST. Unpacking the reasons for this incompatibility makes the nature of the conflation underwriting AST quite clear.

Graziano takes a great number of things for granted in his account, not the least of which is metacognition. Theory is all about taking things for granted, of course, but only the right things. AST, as it turns out, is not only a theory of subjective awareness, it’s also a theory of metacognition. Subjective awareness, on Graziano’s account, is a metacognitive tool. The primary function of the attention schema is to enable executive control of attentional mechanisms. As they write, “[i]n this perspective, awareness is an internal model of attention useful for the control of attention” (5). Consciousness is a metacognitive device, a heuristic the brain uses to direct and allocate attentional (cognitive) resources.

We know that it’s heuristic because, even though Webb and Graziano nowhere reference the research of fast and frugal heuristics, they cover the characteristics essential to them. The attention schema, we are told, provides only the information the brain requires to manage attention and nothing more. In other words, the attention schema possesses what Gerd Gigerenzer and his fellow researchers at the Adaptive Behaviour and Cognition Research Institute call a particular ‘problem ecology,’ one that determines what information gets neglected and what information gets used (see, Ecological Rationality). This heuristic neglect in turn explains why, on Webb and Graziano’s account, subjective awareness seems to possess the peculiar properties it does. When we attend to our attention, the neglect of natural (neurobiological) information cues the intuition that something not natural is going on. Heuristic misapplications, as Wimsatt has long argued, lead to systematic errors.

But of course the feasibility of solving any problem turns on the combination of the information available and the cognitive capacity possessed. Social cognition, for instance, allows us to predict, explain, and manipulate our fellows on the basis of so little information that ‘computational intractibility’ remains a cornerstone of mindreading debates.  In other words, the absence of neurobiological information in the attention schema only explains the apparently supernatural status of subjective awareness given certain metacognitive capacities. Graziano’s attention schema may be a metacognitive tool, a way to manage cognitive resources, but it is the ‘object’ of metacognition as well.

For me, this is where the whole theory simply falls apart—and obviously so. The problem is that the more cognitive neuroscience learns about metacognition, the more fractionate and specialized it appears to be. Each of these ‘kluges’ represents adaptations to certain high impact, environmental problems. The information subjective awareness provides leverages many different solutions to many different kinds of dilemmas, allowing us to bite our tongues at Thanksgiving dinner, ponder our feelings toward so-and-so, recognize our mistakes, compulsively ruminate upon relationships, and so on, while at the same time systematically confounding our attempts to deduce the nature of our souls. The fact is, the information selected, stabilized, and broadcast via consciousness, enables far, far more than simply the ability to manage attention.

But if subjective awareness provides solutions to a myriad of problems given the haphazard collection of metacognitive capacities we possess, then in what sense does it count as a ‘representation of’ the brain’s attentional processes? Is it the case that a heuristic (evolutionarily opportunistic) model of that machinery holds the solution to all problems? Prima facie, at least, the prospects of such a hypothesis seem dim. When trying to gauge our feelings about a romantic partner, is it a ‘representation’ of our brain’s attentional processes that we need, or is it metacognitive access to our affects?

Perhaps sensing this easy exit, Webb and Graziano raise some hasty barricades:

“According to the attention schema theory, the brain constructs a simplified model of the complex process of attention. If the theory is correct, then the attention schema, the construct of awareness, is relevant to any type of information to which the brain can pay attention. The relevant domain covers all vision, audition, touch, indeed any sense, as well as internal thoughts, emotions, and ideas. The brain can allocate attention to all of these types of information. Therefore awareness, the internal representation of attention, should apply to the same range of information.” 9

So even though a representation of the brain’s attentional resources is not what we need when we inspect our feelings regarding another, it remains ‘applicable’ to such an inspection. If we accept that awareness of our feelings is required to inspect our feelings, does this mean that awareness somehow arises on the basis of the ‘applicability’ of the attention schema, or does it mean that the attention schema somehow mediates all such metacognitive activities?

Awareness of our feelings is required to inspect our feelings. This means the attention schema underwrites our ability to inspect our feelings, as should come as no surprise, given that the attention schema underwrites all conscious metacognition. But if the attention schema underwrites all conscious metacognition, it also underwrites all conscious metacognitive functions. And if the attention schema underwrites all conscious metacognitive functions, then, certainly, it models far, far more than mere attention.

The dissociation between subjective awareness and the attention schema seems pretty clear. Consciousness is bigger than attention, and heuristic neglect applies to far more than our attempts to understand the ‘attention schema’—granted there is such a thing.

But what about the post facto ‘predictions’ that Webb and Graziano present as evidence for AST?

Given that consciousness is the attention schema and the primary function of the attention schema is the control of attention, we should expect divergences between attention and awareness, and we should expect convergences between awareness and attentional control. Webb and Graziano adduce experimental evidence of both, subsequently arguing that AST is the best explanation, even though the sheer generality of the theory makes it hard to see the explanatory gain. As it turns out, awareness correlates with attentional control because awareness is an attentional control mechanism, and awareness uncouples with attention because awareness, as a representation of attention, is something different than attention. If you ask me, this kind of ’empirical evidence’ only serves to underscore the problems with the account more generally.

Ultimately, I just really don’t see how AST amounts to a workable theory of consciousness. It could be applied, perhaps, as a workable theory for the appearance of consciousness, but then only as a local application of the far more comprehensive picture of heuristic neglect Blind Brain Theory provides. These limits become especially clear when one considers the social dimensions of AST, where Graziano sees it discharging some of the functions Dennett attributes to the ‘intentional stance.’ But since AST possesses no account of intentionality whatsoever (indeed, Graziano doesn’t seem to be aware of the problems posed by aboutness or content), it completely neglects the intentional dimensions of social cognition. Since social cognition is intentional cognition, it’s hard to understand how AST does much more than substitute a conceptually naïve notion of ‘attention’ for intentionality more broadly construed.

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