Is the mind a machine?

My latest 3QD essay explores the “mind as machine” metaphor, and metaphors in general.

Putting the “cog” in “cognitive”: on the “mind as machine” metaphor

Here’s an excerpt:

People who study the mind and brain often confront the limits of metaphor. In the essay ‘Brain Metaphor and Brain Theory‘, the vision scientist John Daugman draws our attention to the fact that thinkers throughout history have used the latest material technology as a model for the mind and body. In the Katha Upanishad (which Daugman doesn’t mention), the body is a chariot and the mind is the reins. For the pre-Socratic Greeks, hydraulic metaphors for the psyche were popular: imbalances in the four humors produced particular moods and dispositions. By the 18th and 19th centuries, mechanical metaphors predominated in western thinking: the mind worked like clockwork. The machine metaphor has remained with us in some form or the other since the industrial revolution: for many contemporary scientists and philosophers, the only debate seems to be about what sort of machine the mind really is. Is it an electrical circuit? A cybernetic feedback device? A computing machine that manipulates abstract symbols? Some thinkers so convinced that the mind is a computer that they invite us to abandon the notion that the idea is a metaphor. Daugman quotes the cogntive scientist Zenon Pylyshyn, who claimed that “there is no reason why computation ought to be treated merely as a metaphor for cognition, as opposed to the literal nature of cognition”.

Daugman reacts to this Whiggish attitude with a confession of incredulity that many of us can relate to: “who among us finds any recognizable strand of their personhood or of their experience of others and of the world and its passions, to be significantly illuminated by, or distilled in, the metaphor of computation?.” He concludes his essay with the suggestion that “[w]e should remember than the enthusiastically embraced metaphors of each “new era” can become, like their predecessors, as much the prisonhouse of thought as they at first appeared to represent its liberation.”

Read the rest at 3 Quarks Daily:

Putting the “cog” in “cognitive”: on the “mind as machine” metaphor

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Why an organism is not a “machine”

I just came across a nice article explaining why the metaphor of organism as machine is misleading and unhelpful.

The machine conception of the organism in development and evolution: A critical analysis

This excerpt makes a key point:

“Although both organisms and machines operate towards the attainment of particular ends that is, both are purposive systems the former are intrinsically purposive whereas the latter are extrinsically purposive. A machine is extrinsically purposive in the sense that it works towards an end that is external to itself; that is, it does not serve its own interests but those of its maker or user. An organism, on the other hand, is intrinsically purposive in the sense that its activities are directed towards the maintenance of its own organization; that is, it acts on its own behalf.”

In this section the author explains how the software/hardware idea found its way into developmental biology.

“The situation changed considerably in the mid-twentieth century with the advent of modern computing and the introduction of the conceptual distinction between software and hardware. This theoretical innovation enabled the construction of a new kind of machine, the computer, which contains algorithmic sequences of coded instructions or programs that are executed by a central processing unit. In a computer, the software is totally independent from the hardware that runs it. A program can be transferred from one computer and run in another. Moreover, the execution of a program is always carried out in exactly the same fashion, regardless of the number of times it is run and of the hardware that runs it. The computer is thus a machine with Cartesian and Laplacian overtones. It is Cartesian because the software/hardware distinction echoes the soul/body dualism: the computer has an immaterial ‘soul’ (the software) that governs the operations of a material ‘body’ (the hardware). And it is Laplacian because the execution of a program is completely deterministic and fully predictable, at least in principle. These and other features made the computer a very attractive theoretical model for those concerned with elucidating the role of genes in development in the early days of molecular biology.”

The machine conception of the organism in development and evolution: A critical analysis

I’ve actually criticized the genetic program metaphor myself, in the following 3QD essay:

3quarksdaily: How informative is the concept of biological information?

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Image source: Digesting Duck – Wikipedia

“Conscious realism”: a new way to think about reality (or the lack thereof?)

Venn

Interesting interview in the Atlantic with cognitive scientist Donald D. Hoffman:

The Case Against Reality

“I call it conscious realism: Objective reality is just conscious agents, just points of view. Interestingly, I can take two conscious agents and have them interact, and the mathematical structure of that interaction also satisfies the definition of a conscious agent. This mathematics is telling me something. I can take two minds, and they can generate a new, unified single mind. Here’s a concrete example. We have two hemispheres in our brain. But when you do a split-brain operation, a complete transection of the corpus callosum, you get clear evidence of two separate consciousnesses. Before that slicing happened, it seemed there was a single unified consciousness. So it’s not implausible that there is a single conscious agent. And yet it’s also the case that there are two conscious agents there, and you can see that when they’re split. I didn’t expect that, the mathematics forced me to recognize this. It suggests that I can take separate observers, put them together and create new observers, and keep doing this ad infinitum. It’s conscious agents all the way down.”

[…]

Here’s the striking thing about that. I can pull the W out of the model and stick a conscious agent in its place and get a circuit of conscious agents. In fact, you can have whole networks of arbitrary complexity. And that’s the world.

[…]

“As a conscious realist, I am postulating conscious experiences as ontological primitives, the most basic ingredients of the world. I’m claiming that experiences are the real coin of the realm. The experiences of everyday life—my real feeling of a headache, my real taste of chocolate—that really is the ultimate nature of reality.”

I don’t agree with everything in the article (especially the quantum stuff) but I think many people interested in consciousness and metaphysics will find plenty of food for thought here:

The Case Against Reality

Also, the “conscious agents all the way down” is the exact position I was criticizing in a recent 3QD essay:

3quarksdaily: Persons all the way down: On viewing the scientific conception of the self from the inside out

The diagram above is from a science fiction story I was working on, back when I was a callow youth. It closely related to the idea of a network of conscious agents. Here’s another ‘version’ of it.

TriHead

Not sure why I made it look so morbid. 🙂

Where do thoughts come from?

Here’s my answer to a recent Quora question: Where do our thoughts come from?

Thoughts come from nowhere! And from everywhere! I think both answers contain an element of truth.

Subjectively, our thoughts come from nowhere: they just pop into our heads, or emerge in the form of words leaving our mouths.

Objectively, we can say that thoughts emerge from neural processes, and that neural processes come from everywhere. What I mean by this is that the forms and dynamics of thought are influenced by everything that has a causal connection with you, your society, and your species.

We don’t know exactly how thoughts emerge from the activity of neurons — or even how to define what a thought is in biological terms (!)— but there is plenty of indirect evidence to support the general claim that the brain is where thoughts emerge.

The neuronal patterns that mediate and enable thought and behavior have proximal and distal causes.

The proximal causes are the stimuli and circumstances we experience. These experiences have causal impacts on our bodies, and are also partly caused by our bodies. The forces inside and outside the body become manifest in the brain as ‘clouds’ of information. In the right circumstances these nebulous patterns can condense into streams of thought. We can add to these identifiable causes the mysterious element of randomness: that seemingly ever-present “ghost in the machine” that makes complex processes such as life fundamentally unpredictable. Perhaps randomness is what provides the ‘seeds’ around which the condensation of thoughts can occur.

The distal causes are our experiential history and our evolutionary pre-history. Our experiential history consists of the things we’ve learned, consciously and unconsciously, and the various events that have shaped our bodies and our neural connections in large and small ways. Our evolutionary pre-history is essentially the experiential history of our species, and more generally of life itself, going back all the way to the first single-celled organism. The traits of a species are a sort of historical record of successes and failures. And going even further, life ultimately takes its particular forms because of the possibilities inherent in matter — and this takes us all the way to the formation of stars and planets.

Me and My Brain: What the “Double-Subject Fallacy” reveals about contemporary conceptions of the Self

MiBMy latest essay for 3 Quarks Daily is up: Me and My Brain: What the “Double-Subject Fallacy” reveals about contemporary conceptions of the Self

Here’s an excerpt:
What is a person? Does each of us have some fundamental essence? Is it the body? Is it the mind? Is it something else entirely? Versions of this question seem always to have animated human thought. In the aftermath of the scientific revolution, it seems as if one category of answer — the dualist idea that the essence of a person is an incorporeal soul that inhabits a material body — must be ruled out. But as it turns out, internalizing a non-dualist conception of the self is actually rather challenging for most people, including neuroscientists.
[…]
 A recent paper in the Journal of Cognitive Neuroscience suggests that even experts in the sciences of mind and brain find it difficult to shake off dualistic intuitions. Liad Mudrik and Uri Maoz, in their paper “Me & My Brain”: Exposing Neuroscienceʼs Closet Dualism, argue that not only do neuroscientists frequently lapse into dualistic thinking, they also attribute high-level mental states to the brain, treating these states as distinct from the mental states of the person as a whole. They call this the double-subject fallacy. ( I will refer to the fallacy as “dub-sub”, and the process of engaging in it as “dub-subbing”.) Dub-subbing is going on in constructions like”my brain knew before I did” or “my brain is hiding information from me”. In addition to the traditional subject — “me”, the self, the mind — there is a second subject, the brain, which is described in anthropomorphic terms such as ‘knowing’ or ‘hiding’. But ‘knowing’ and ‘hiding’ are precisely the sorts of things that we look to neuroscience to explain; when we fall prey to the double-subject fallacy we are actually doing the opposite of what we set out to do as materialists.  Rather than explaining “me” in terms of physical brain processes, dub-subbing induces us to describe the brain in terms of an obscure second “me”. Instead of dispelling those pesky spirits, we allow them to proliferate!
Read the whole thing at 3QD:

The Neural Citadel — a wildly speculative metaphor for how the brain works

My latest 3QD essay is a bit of a wild one. I start by talking about Goodhart’s Law, a quirk of economics that I think has implications elsewhere. I try to link it with neuroscience, but in order to do so I first construct an analogy between the brain and an economy. We might not understand economic networks any better than we do neural networks, but this analogy is a fun way to re-frame matters of neuroscience and society.

Plan of a Citadel (from Wikipedia)

Plan of a Citadel (from Wikipedia)

Here’s an excerpt:

The Neural Citadel

Nowadays we routinely encounter descriptions of the brain as a computer, especially in the pop science world. Just like computers, brains accept inputs (sensations from the world) and produce outputs (speech, action, and influence on internal organs). Within the world of neuroscience there is a widespread belief that the computer metaphor becomes unhelpful very quickly, and that new analogies must be sought. So you can also come across conceptions of the brain as a dynamical system, or as a network. One of the purposes of a metaphor is to link things we understand (like computers) with thing we are still stymied by (like brains). Since the educated public has plenty of experience with computers, but at best nebulous conceptions of dynamical systems and networks, it makes sense that the computer metaphor is the most popular one. In fact, outside of a relatively small group of mathematically-minded thinkers, even scientists often feel most comfortable thinking of the brain as a elaborate biological computer. [3]

However, there is another metaphor for the brain that most human beings will be able to relate to. The brain can be thought of as an economy: as a biological social network, in which the manufacturers, marketers, consumers, government officials and investors are neurons. Before going any further, let me declare up front that this analogy has a fundamental flaw. The purpose of metaphor is to understand the unknown — in this case the brain — in terms of the known. But with all due respect to economists and other social scientists, we still don’t actually understand socio-economic networks all that well. Not nearly as well as computer scientists understand computers. Nevertheless, we are all embedded in economies and social networks, and therefore have intuitions, suspicions, ideologies, and conspiracy theories about how they work.

Because of its fundamental flaw, the brain-as-economy metaphor isn’t really going to make my fellow neuroscientists’ jobs any easier, which is why I am writing about it on 3 Quarks Daily rather than in a peer-reviewed academic journal. What the brain-as-economy metaphor does do is allow us to translate neural or mental phenomena into the language of social cooperation and competition, and vice versa. Even though brains and economies seem equally mysterious and unpredictable, perhaps in attempting to bridge the two domains something can be gained in translation. If nothing else, we can expect some amusing raw material for armchair philosophizing about life, the universe, and everything. [4]

So let’s paint a picture of the neural economy. Imagine that the brain is a city — the capital of the vast country that is the body. The neural citadel is a fortress; the blood-brain barrier serves as its defensive wall, protecting it from the goings-on in the countryside, and only allowing certain raw materials through its heavily guarded gates — oxygen and nutrients, for the most part. Fuel for the crucial work carried out by the city’s residents: the neurons and their helper cells. The citadel needs all this fuel to deal with its main task: the industrial scale transformation of raw data into refined information. The unprocessed data pours into the citadel through the various axonal highways.  The trucks carrying the data are dispatched by the nervous system’s network of spies and informants. Their job is to inform the citadel of the goings-on outside its walls. The external sense organs — the eyes, ears, nose, tongue and skin — are the body’s border patrols, coast guards, observatories, and foreign intelligence agencies. The muscles and internal organs, meanwhile, are monitored by the home ministry’s police and bureaucrats, always on the look-out for any domestic turbulence. (The stomach, for instance, is known to be a hotbed of labor unrest.)

The neural citadel enables an information economy — a marketplace of ideas, as it were. Most of this information is manufactured within the brain and internally traded, but some of it — perhaps the most important information — is exported from the brain in the form of executive orders, requests and the occasional plaintive plea from the citadel to the sense organs, muscles, glands and viscera. The purpose of the brain is definitely subject to debate — even within the citadel — but one thing most people can agree on is that it must serve as an effective and just ruler of the body: a government that marries a harmonious domestic policy — unstressed stomach cells, unblackened lung cells, radiant skin cells and resilient muscle cells — with a peaceful and profitable foreign policy. (The country is frustratingly dependent on foreign countries, over which it has limited control, for its energy and construction material.)

The citadel is divided into various neighborhoods, according to the types of information being processed. There are neighborhoods subject to strict zoning requirements that process only one sort of information: visions, sounds, smells, tastes, or textures. Then there are mixed use neighborhoods where different kinds of information are assembled into more complex packages, endlessly remixed and recontextualized. These neighborhoods are not arranged in a strict hierarchy. Allegiances can form and dissolve. Each is trying to do something useful with the information that is fed to it: to use older information to predict future trends, or to stay on the look-out for a particular pattern that might arise in the body, the outside world, or some other part of the citadel.  Each neighborhood has an assortment of manufacturing strategies, polling systems, research groups, and experimental start-up incubators. Though they are all working for the welfare of the country, they sometimes compete for the privilege of contributing to governmental policies. These policies seem to be formulated at the centers of planning and coordination in the prefrontal cortex — an ivory tower (or a corporate skyscraper, if you prefer merchant princes to philosopher kings) that has a panoramic view of the citadel. The prefrontal tower then dispatches its decisions to the motor control areas of the citadel, which notify the body of governmental marching orders.

~

The essay is not just about the metaphor though. There are bits about dopamine, and addiction, and also some wide-eyed idealism. 🙂 Check the whole thing out at 3 Quarks Daily.

For the record, there is a major problem with personifying neurons. It doesn’t actually explain anything, since we are just as baffled by persons as we are by neurons. Personifying neurons creates billions of microscopic homunculi. The Neural Citadel metaphor was devised in a spirit of play, rather than as serious science or philosophy.

What are the limits of neuroscience?

[My answer to a recent Quora question.]

There are two major problems with neuroscience:

  1. Weak philosophical foundations when dealing with mental concepts
  2. Questionable statistical analyses of experimental results

1. Neuroscience needs a bit of philosophy

Many neuroscientific results are presented without sufficiently nuanced  philosophical knowledge. This can lead to cartoonish and potentially harmful conceptions of the brain, and by extension, of human behavior, psychology, and culture. Concepts related to the mind are among the hardest to pin down, and yet some neuroscientists give the impression that there are no issues that require philosophical reflection.

Because of a certain disdain for philosophy (and sometimes even psychology!), some neuroscientists end up drawing inappropriate inferences from their research, or distorting the meaning of their results.

One particularly egregious example is the “double subject fallacy”, which was recently discussed in an important paper:

“Me & my brain”: exposing neuroscience’s closet dualism.

Here’s the abstract of the paper:

Our intuitive concept of the relations between brain and mind is  increasingly challenged by the scientific world view. Yet, although few  neuroscientists openly endorse Cartesian dualism, careful reading  reveals dualistic intuitions in prominent neuroscientific texts. Here,  we present the “double-subject fallacy”: treating the brain and the  entire person as two independent subjects who can simultaneously occupy  divergent psychological states and even have complex interactions with  each other-as in “my brain knew before I did.” Although at first, such  writing may appear like harmless, or even cute, shorthand, a closer look  suggests that it can be seriously misleading. Surprisingly, this  confused writing appears in various cognitive-neuroscience texts, from  prominent peer-reviewed articles to books intended for lay audience. Far  from being merely metaphorical or figurative, this type of writing  demonstrates that dualistic intuitions are still deeply rooted in  contemporary thought, affecting even the most rigorous practitioners of  the neuroscientific method. We discuss the origins of such writing and  its effects on the scientific arena as well as demonstrate its relevance  to the debate on legal and moral responsibility.

[My answer to the earlier question raises related issues: What are the limits of neuroscience with respect to subjectivity, identity, self-reflection, and choice?]

2. Neuroscience needs higher data analysis standards

On a more practical level, neuroscience is besieged by problems related to bad statistics. The data in neuroscience (and all “complex system” science) are extremely noisy, so increasingly sophisticated statistical techniques are deployed to extract meaning from them. This sophistication means that  fewer and fewer neuroscientists actually understand the math behind the statistical methods they employ. This can create a variety of problems, including incorrect inferences. Scientists looking for “sexy” results can use poorly understood methods to show ‘significant’ effects where there really is only a random fluke. (The more methods you use, the more chances you create for finding a random “statistically significant” effect. This kind of thing has been called “torturing the data until it confesses”.)

Chance effects are unreproducible, and this is a major problem for many branches of science. Replication is central to good science, so when it frequently fails to occur, then we know there are problems with research and with how it is reviewed and published. Many times there is a “flash in the pan” at a laboratory that turns out to be fool’s gold.

See these article for more:

Bad Stats Plague Neuroscience

Voodoo Correlations in Social Neuroscience

The Dangers of Double Dipping (Voodoo IV)

Erroneous analyses of interactions in neuroscience: a problem of significance.

Fixing Science, Not Just Psychology – Neuroskeptic

The Replication Problem in the Brain Sciences


Quora: What are the limits of neuroscience?