Saturday, August 20, 2005

Fall Book Selection

This fall we'll be reading Micheal Tomasello's The Cultural Origins of Human Cognition [Amazon $20.95]. Tomasello presents an alternative to the idea from Evolutionary Psychology (along with Chomskian nativism) that we evolved to use a special language organ in the brain. Instead, Tomasello argues, by contrasting human theory-of-mind abilities with those of primates and autistic children that we can see that the broad-based cognitive mechanisms that provide for cultural learning generally can be used specifically to promote language learning in humans.

UPDATE [08.26.05] We will meet every other Wednesday at noon in SC 200, beginning September 14 (discuss first chapter).

We can use this blog to post discussion items, background information, and interesting links relevant to the book (or anything neuro-). Another online discussion of this book is led at the Mixing Memory blog.

Wednesday, August 17, 2005

"Francis and I co-opted this catchy term"

Reaching the end of the Quest, I thought I would revisit my previous post where I picked over a half page section of Koch's book. Yes, things are clearer now.

First, the nature of the Quest is clear. It is a quest for neurons that spike in primates when scientists observe those primates indicating their awareness of (mostly visual) stimuli. Yes, this approach takes first person accounts seriously, but of course when the scientist observes someone else's first person account, it is a third person account. And in the scientific papers (though not in the semipopular books spinning off therefrom) it is always somebody else (some monkey, etc. )

Second, it is clear Koch's zombie is not the philosophers' zombie, by definition. "Francis and I co-opted this catchy term for the set of rapid, stereotyped sensory-motor behaviors that [not "which"?!] are insufficient, by themselves, for conscious sensations." So in the paragraph I wrote about earlier (section 14.3), the statement that we cannot have a zombie executive summarizer just means that executive summarizing is not a rapid, stereotyped sensory-motor behavior. Yep.

Third, it is clear Koch's qualia are not the philosophers' qualia, by definition. Qualia are "a symbolic form of representation of all this vast ocean of explicit and implicit information". Qualia are not "first-person feels" or anything like that. ("Why qualia feel the way they do remains an enigma [p. 310].")

So in fact, we are in a Dennett-friendly science zone here. Koch's quest is solid cognitive neuroscience. As he leads us on his quest he shows us some fascinating neuro facts, and everything culminates in a theory on the neural implementation of (heterophenomenological) visual awareness and executive summarizers.

Good.

But, this is not quite the whole story of the Quest. Koch redefines some terms (zombie, qualia, even consciousness), stripping them of their heavy philosophical baggage and philosophical grandeur, leaving them as modest, clear cog neuro terms. Alright. But then, as he gives us his theory, he often speaks as if he was giving us a theory of the terms in their original, grand philosophical meanings. For example, on p.318 (which is a rephrasing section 14.3), he writes, "Some simple creatures may be nothing but bundles of zombie agents. Thus, it might not feel like anything to be a snail or a roundworm." He's acting as if his down-defined term "zombie" carries the philosophical weight of the philosopher's zombie. There's a big hunk of philosophy that must be embedded in that "Thus."

This way of writing culminates on the penultimate page (p.326) in the ultimate conceit, that he is on his way to creating an objective theory of consciousness that will disturb some people, being dehumanizingly objective. Well, I think explaining our executive summarizers and condensed sensory representations in neural terms will not be terribly upsetting to anybody, but he wants to somehow leave the impression that he's out to explain "consciouness" and "qualia" in their most profound sense. And he believes his cog neuro theory will give answers to philosophical questions.

Will they? As we read on p.317, "philosophy does not have an impressive record of answering questions" decisively (though this cannot be brought up in "polite, academic company"). We should listen to philosophers, he tells us, but not be distracted by their answers.

And, here, we see, for all those five years he spent writing the book, he has missed the point. He and the philosophers are not asking the same questions. His book makes it seem like he is asking the same questions (and, unlike those silly philosophers, he's finally getting some answers!). But this is only because he and Francis "co-opt" philosophical terms. If he had just done that, that could be fine, good science. But he conintually pretends their original philosophical import is still there.

Why? Part of it must be marketing, selling one's work as directly answering Age-Old questions. (Are spiny stellate cells involved in summarizing visual stimuli? Not an Age-Old question. Let's rephrase...) Of course, these modest questions can lead along a path --a quest!-- to answer truly deep questions, but a good writer will keep the distinctions sharp and the path clear. Is this a harsh judgement? This is a blog, so of course I can be harsh. I must admit that the "not in polite company" remark about philosophers, like many other catty remarks throughout the book (not to mention the lookit-me rock climbing bits), have left me cold.

That being said... [change of tone] the book truly is an exciting and informative tour of the neural landscape. "Recommended!"

Sunday, August 14, 2005

Books for Fall

We need to find a book to discuss this fall. A couple of ideas have surfaced, and I'm sure there are others. If you have ideas, comment on this post or email me.

Daniel Dennett, Sweet Dreams [Amazon] An accessible reworking of Dennett's views on consciousness. He pays special attention to zombies and qualia.

Michael Gazzaniga, The Ethical Brain [Amazon] Gazzaniga talks about issues like stem cell research, the uses and abuses of neuroscience in making ethical decisions, and a neuroscientific take on how we form moral judgments.

At Mixing Memory they've chosen Michael Tomasello's book The Cultural Origins of Human Cognition for an online reading group. [Amazon] They provide a blog entry with background and context to the book, which presents an alternative to the idea from Evolutionary Psychology that we evolved to use a special language organ in the brain. Instead, Tomasello argues, by contrasting human theory-of-mind abilities with those of primates and autistic children that we can see that the broad-based cognitive mechanisms that provide for cultural learning generally can be used specifically to promote language learning in humans. (Here and here are background papers.)

There are also some interesting books on evolution and the brain (or human cognition). William Calvin, A Brief History of the MInd; Merlin Donald, Origins of the Modern Mind, Donald again, A Mind So Rare, and Nicholas Humphrey, A History of the Mind.

I think the Quartz/Sejnowski book Liars, Lovers, and Heroes should also be on the list. It's a very readible defense of the plasticity of the brain.

Friday, August 05, 2005

Dispensing with Consciousness

Following Mark's lead, this post starts with a Madonna lyric [sic], her take on a famous quale: "Pain is a warning that something's wrong" ("The Power of Goodbye", Ray of Light, 1998). I want to briefly comment a passage seemingly composed at the same level of reflective rigor, section 14.3 of Christof Koch's The Quest for Consciousness. This note gathers up some thoughts spinning out from Wednesday's NKU Cog Neuro Reading Group, where we were discussing Chapters 14 and 15. I must qualify this note by saying that I have not read ahead, so this is a mere snapshot of my developing response to Koch's book.

Koch's four-paragraph section bears much of the philosophical weight of the book, of his Quest, and gives us a chance to see his argumentation at work. Entitled "Why the Brain Is Not Just a Bundle of Zombie Agents," it looks like it will deliver a concise answer. Let's see.

At this point in the book, the reader will have learned that brains employ a multitude "zombie agents" to handle many perceptual and motor tasks that lie beneath our attention. (The identification of zombie agents is not unproblematic. A single neuron, for example, seems to fulfill the requirements for zombie agenthood, but that is another story.) So the section heading leads us to ask, if the brain is not just a bundle of zombie agents, what else does it contain?

Paragraph 1: Consciousness, of course. Here we find Koch stating that to "dispense with consciousness" is to dispense with "conscious planning." Well, that's a safe inference! But he's not saying that would dispense with "planning," of course, so we have learned nothing at this point.

Paragraph 2. Here Koch states that "breeding zombie agents for all possible input/output combinations is probably inefficient." What could this mean? My brain's zombie agents can handle all possible (natural) inputs. What zombie agents (and artificial neural nets) do is reduce the dimensionality of information, construct representations, tag items by relevance, and so on. But not only is the statement hard to understand, it seems to be a non sequitur. Why would dispensing with consciousness necessitate breeding zombie agents for all I/O combinations? A few sentences later we see him saying that this would require "something that coordinates their actions." At first glance, this might seem to be consciousness, but, as written, the full-I/O zombies together with this coordinator, are what is rejected as too big and inflexible. Compared to what? Compared to "zombie agents with a more flexible conscious module." How did the word "conscious" slip in that phrase? The claim is merely that it is better (more fit in a Darwinian sense) to have a brain architecture that is more flexible rather than less. (Wow.) Nothing in this paragraph argues that consciousness gives that extra flexibility. The term is slipped in quietly just as in the last paragraph: "planning" became "conscious planning", "flexible module" becomes "flexible conscious module".

Paragraph 3. This is a three sentence interjection, to reassure us that he is not saying that such a nonconscious architecture is impossible; he is merely asserting that it is unlikely to have emerged through evolution.

Paragraph 4. He puts forth an analogy: the contrast (which he exaggerates) between specialized low-powered embedded dedicated processors (e.g. in mobile phones) with expensive "power-hungry" CPUs in personal computers. He says truly adaptive robot (or other artifact) will make use of both. In fact, what would make a robot truly adaptive has been the subject of decades of research in evolutionary computing and AI, and one thing that is clear is that having a strict separation of two classes of discrete digital proceessors is at best irrelevant or at worst maladaptive. And, alas, there is no logical connection to the question of the title of this section. The paragraph can only be read as analogizing zombie agents to the little processors in your cell phone, and consciousness to the Pentium 4 your desktop. This is not helpful to his story!

And so we reach the end of the section. The problem is not an invalid argument. The problem is that we are led to expect an argument but what we get is incoherent, a kind of free association on a theme. The "Why" in the section heading is unanswered. ...

So, I fear something has gone wrong. Like some of Penrose's books, we have a superbly written semi-technical introduction to a scientific field --engaging, up-to-date, rich in detail-- yet at its core are strong claims about deep issues that simply do not hold up. One wishes he were not so hard on philosophers and their "eristic" argumentation; certainly some of their precision and rigor would have been useful here!

Neuroscience minor website

This is my first blog post ever. To quote Madonna (as is the secret desire of all pointy headed liberal academics), "Like a virgin".

Anyway, Tony, our website developer extraordinare, has put together a website for the NKU Neuroscience minor. It is located on the web at:

http://ky-brin.nku.edu/NEUROSCIENCE.htm

It will likely move to the NKU Psychology Department website (www.nku.psych) sometime soon, but it's at our KY-BRIN site right now.

Tuesday, June 28, 2005

Grandmother Cells?

Does a single neuron code for Bart Simpson's face? Mind Hacks reports on an article in Nature suggesting some evidence for 'grandmother cells.'
This week's edition of the science journal Nature reports that single brain cells may be specialised for recognising specific faces.

This is an interesting finding, as it provides support for a derided hypothesis known as the 'grandmother cell' theory, that was thought up to ridicule attempts to reduce human experience down to smaller and smaller components of the brain.

Neuroscience often develops by trying to understanding how smaller parts of the brain support larger processes. Bologist Jerry Lettvin argued that we can't expect everything to reduce down to the smallest level, as some things will be distributed across the brain.

It is unlikely, he argued, that there is a single brain cell to represent each person we know, a neuron that is active when we see our grandmother, for example.

This has since been used as an argument against any theory that is seen as over-simplifying how things are represented in the brain.

But now, a team led by neuroscientist Rodrigo Quian Quiroga has identified neurons which do seem to be active for individual faces.

He implanted harmless electrodes into the temporal lobes of volunteers undergoing surgery for epilepsy.

Quiroga then showed the participants pictures of famous faces, and discovered some cells were only active for individual faces in the set - Halle Berry, or even members of The Simpsons.

Of course, it's impossible to say whether these cells are truly selective for an individual face out of all the ones a person may know, but this level of selectivity is a great surprise for those who thought individual cells would be active for very general features of the visual world.

Friday, June 24, 2005

Koch Discussion

We meet next Wednesday at noon in SC 200 to discuss Koch, chs 8-10.

You can watch Kock's video lectures, based on the text, at http://www.klab.caltech.edu/cns120/videos.php

Wednesday, June 15, 2005

Koch discussion continues

The Quest For Consciousness discuss group meets next Wednesday, June 21, at noon in SC 200. We'll discuss chs. 5-7.

Here are a number of additional online articles you might find useful:

David Chalmers, "What is a Neural Correlate of Consciousness?" in Neural Correlates of Consciousness: Empirical and Conceptual Issues, Metzinger, ed.

A. Noe and E. Thompson, "Are there Neural Correlates of Consciousness?" from Journal of Consciousness Studies

Ned Block, "How to Find the Neural Correlates of Consciousness"

Thursday, June 09, 2005

Welcome to Neuroscience at NKU

Look to this web log for news, information, commentary, book reviews, and anything even remotely related to the study of neuroscience at Northern Kentucky University. Members of the blog include faculty and students interested in addressing a broad range of topics on the Mind-Brain from a variety of disciplinary perspectives.

Koch Links

Koch has a website for his book The Quest for Consciousness with some sample chapters and information about the author.

Some Crick-Koch articles:
"A Framework for Consciousness" in Nature Neuroscience 6(2):119-126, 2003.
"Consciousness and Neuroscience" in Cerebral Cortex, 8:97-107, 1998.
"The Problem of Consciousness" in Scientific American, Sept. 1992

Also, here are some links to online reviews of Koch's book.

Interview with Koch
Hameroff review
Chris Frith review
Bernard Baars review
Martinez-Conde review
Jeremy Wolfe review
Searle review in NYRB (01.13.05) [requires password]
Harnad-Searle exchange in NYRB (06.23.05)

Discussion Group Meeting

The next CNS discussion group meeting is Wednesday, June 14 at 12:00 in SC 200. We'll discuss Koch's The Quest for Consciousness, chapters 3 and 4.