brain

All posts tagged brain

Mirror Neurons

Posted by Peter on October 12, 2015
Posted in: Book Reviews, The Human Mind. Tagged: , , .

Book review: The Myth of Mirror Neurons: The Real Neuroscience of Communication and Cognition, by Gregory Hickok.

This book criticizes hype from scientists and the media about embodied cognition, mirror neurons, and the differences between the left and right brain hemispheres. Popular accounts of these ideas contain a little bit of truth, but most versions either explain very little or provide misleading explanations.

A good deal of our cognition is embodied in the sense that it’s heavily dependent on sensory and motor activity. But we have many high-level thoughts that don’t fit this model well, such as those we generate when we don’t have sensory or motor interactions that are worth our attention (often misleading called a “resting state”).

Humans probably have mirror neurons. They have some value in helping us imitate others. But that doesn’t mean they have much affect on our ability to understand what we’re imitating. Our ability to understand a dog wagging its tail isn’t impaired by our inability to wag our tails. Parrots’ ability to imitate our speech isn’t very effective at helping them understand it.

Mirror neurons have also been used to promote the “broken mirror theory” of autism (with the suggestion that a malfunction related to mirror neurons impairs empathy). Hickok shows that the intense world hypothesis (which I’ve blogged about before) is more consistent with the available evidence.

The book clarified my understanding of the brain a bit. But most of it seems unimportant. I had sort of accepted mild versions of the mirror neuron and left-brain, right brain hype, but doing so didn’t have any obvious effects on my other beliefs or my actions. It was only at the book’s end (discussing autism) that I could see how the hype might matter.

Most of the ideas that he criticizes don’t do much harm, because they wouldn’t pay much rent if true. Identifying which neurons do what has negligible effect on how I model a person’s mind unless I’m doing something unusual like brain surgery.

Self Comes to Mind

Posted by Peter on November 20, 2013
Posted in: Book Reviews, The Human Mind. Tagged: , , .

Book review: Self Comes to Mind: Constructing the Conscious Brain by Antonio R. Damasio.

This book describes many aspects of human minds in ways that aren’t wrong, but the parts that seem novel don’t have important implications.

He devotes a sizable part of the book to describing how memory works, but I don’t understand memory any better than I did before.

His perspective often seems slightly confusing or wrong. The clearest example I noticed was his belief (in the context of pre-historic humans) that “it is inconceivable that concern [as expressed in special treatment of the dead] or interpretation could arise in the absence of a robust self”. There may be good reasons for considering it improbable that humans developed burial rituals before developing Damasio’s notion of self, but anyone who is familiar with Julian Jaynes (as Damasio is) ought to be able to imagine that (and stranger ideas).

He pays a lot of attention to the location in the brain of various mental processes (e.g. his somewhat surprising claim that the brainstem plays an important role in consciousness), but rarely suggests how we could draw any inferences from that about how normal minds behave.

The Intelligence Paradox

Posted by Peter on July 3, 2012
Posted in: Book Reviews, The Human Mind. Tagged: , , .

Book review: The Intelligence Paradox: Why the Intelligent Choice Isn’t Always the Smart One, by Satoshi Kanazawa.

This book is entertaining and occasionally thought-provoking, but not very well thought out.

The main idea is that intelligence (what IQ tests measure) is an adaptation for evolutionarily novel situations, and shouldn’t be positively correlated with cognitive abilities that are specialized for evolutionarily familiar problems. He defines “smart” so that it’s very different from intelligence. His notion of smart includes a good deal of common sense that is unconnected with IQ.

He only provides one example of an evolutionarily familiar skill which I assumed would be correlated with IQ but which isn’t: finding your way in situations such as woods where there’s some risk of getting lost.

He does make and test many odd predictions about high IQ people being more likely to engage in evolutionarily novel behavior, such as high IQ people going to bed later than low IQ people. But I’m a bit concerned at the large number of factors he controls for before showing associations (e.g. 19 factors for alcohol use). How hard would it be to try many combinations and only report results when he got conclusions that fit his prediction? On the other hand, he can’t be trying too hard to reject all evidence that conflicts with his predictions, since he occasionally reports evidence that conflicts with his predictions (e.g. tobacco use).

He reports that fertility is heritable, and finds that puzzling. He gives a kin selection based argument saying that someone with many siblings ought to put more effort into the siblings reproductive success and less into personally reproducing. But I see no puzzle – I expect people to have varying intuitions about whether the current abundance of food will last, and pursue different strategies, some of which will be better if food remains abundant, and others better if overpopulation produces a famine.

He’s eager to sound controversial, and his chapter titles will certainly offend some people. Sometimes those are backed up by genuinely unpopular claims, sometimes the substance is less interesting. E.g. the chapter title “Why Homosexuals Are More Intelligent than Heterosexuals” says there’s probably no connection between intelligence and homosexual desires, but there’s a connection between intelligence and how willing people are to act on those desires (yawn).

Here is some evidence against his main hypothesis.

Neanderthal Brains and Eye Size

Posted by Peter on March 26, 2012
Posted in: Uncategorized. Tagged: , .

A post titled Neanderthals had differently organized brains reports evidence that Neanderthal brains did not have a larger volume devoted to intelligence (or at least that part of intelligence needed to handle social interactions in large groups) than humans.

A key fact is that “eye-socket size is correlated with latitude” – at least within a species.

Neanderthals were adapted to high latitudes, and had larger eye-sockets.

That suggests a relatively large part of their brain was devoted to the visual cortex, and it seems somewhat plausible to suspect that much of that involved low-level processing needed to make up for darker conditions at higher latitudes.

So Neanderthals’ larger skull size doesn’t imply any important advantage.

Stroke of Insight

Posted by Peter on March 4, 2009
Posted in: Book Reviews, The Human Mind. Tagged: , , .

Book review: My Stroke of Insight: A Brain Scientist’s Personal Journey by Jill Bolte Taylor.

This book provides a unique description of the differences between the left and right sides of the brain, because she experienced about as big a decrease in the functioning of her left hemisphere as anyone who has recovered enough to write about it. It’s a very quick read, but didn’t have as much information as I’d hoped.

She makes plausible claims (with minimal mysticism) that her stroke helped her experience nirvana and continues to help her choose to have the best parts of her brain dominate her personality. It makes me wish there were something better than the Wada test that would enable the rest of us to more safely experiment with such experiences.

It helps me understand what I’m not accomplishing when I try (with little success) to meditate, but it appears that her advice for how to do better only works for people who are starting with a mind that is less strongly dominated by the left brain than mine.

It’s important to remember that the parts of her brain that are reporting the benefits of her experience are the ones that survived. We have little information about how the parts of her brain that died would have evaluated the experience.

Adapting Minds

Posted by Peter on March 6, 2006
Posted in: Book Reviews, The Human Mind. Tagged: , .

Book Review: Adapting Minds : Evolutionary Psychology and the Persistent Quest for Human Nature by David J. Buller
This book makes a strong case that there are problems with claims put forth by leading Evolutionary Psychologists, but the problems are somewhat less important than the book tries to imply.
This is the most serious and careful attack on Evolutionary Psychologists so far. But it is often hard to tell to what extent the theoretical claims he attacks are reflect bad theories or whether some of them are just careless misstatements by people who are too focused on attacking the tabula rasa worldview to worry about criticisms from other viewpoints. For instance, it’s hard to believe that the Evolutionary Psychologists mean the word “universal” in the phrase universal human nature as literally as Buller takes it.
He presents strong arguments that Evolutionary Psychologists have overstated the extent to which dna encodes specialized mental modules, and presents detailed arguments that their empirical results have been sloppy and at least slightly biased against the idea of a general-purpose mind. But if Evolutionary Psychologists are willing to modify their theory to refer to somewhat less specialized modules whose features are influenced by dna in less direct and more subtle ways, then the features of their theories that they seem to consider most important will survive.
His analogy with the immune system illustrates how a system that looks at first glance like it requires some fairly detailed genetic blueprints can actually be caused by a general purpose system that learns most of its specializations by reacting to the environment.
This is not in any way an attack on the idea of using evolutionary theory to understand the mind. In fact, he even points out that Evolutionary Psychologists have been overly interested in questions asked by creationists rather than those that evolutionary theory suggests are important.
Ironically for a philosophy professor, his weakest arguments are the most philosophical ones. He correctly points out the problems with using an essentialist notion of species that is based on universal phenotypic characteristics, but then proposes a definition of species based on continuity and spatiotemporal localization that seems as essentialist and as far from what people actually mean by the word as the definition he criticizes. If I understand his definition correctly, it implies that recreating a Dodo from dna would produce a new species. He should study the philosophy of concepts a bit more (e.g. Lakoff or the neural net literature) and decide that the concept of species doesn’t need either type of essence, but can instead be a more probabilistic combination of several kinds of attributes.

The God Gene

Posted by Peter on October 18, 2005
Posted in: Book Reviews, The Human Mind. Tagged: , , .

Book Review: The God Gene : How Faith Is Hardwired into Our Genes by Dean H. Hamer
This book is entertaining but erratic. To start with, the title is misleading. The important parts of the book are about spirituality (as in what Buddhists seek), which has little connection with God or churches. He does a moderately good job of describing evidence that he has identified a gene that influences spirituality. He makes plausible claims that spirituality makes people happy (that part of the book resembles the works of Csikszentmihalyi and Seligman). He makes a half-hearted attempt to argue that spirituality has evolutionary advantages which isn’t very convincing by itself, but in combination with the sexual selection arguments in Miller’s book The Mating Mind it becomes moderately plausible.
About halfway through the book, he runs out of things to say on those subjects and proceeds to wander through a bunch of marginally related subjects.
His descriptions of psilocybin, prozac, and ecstasy were interesting enough to make me want to learn more about those and similar drugs.
His claims that placebos are effective seem very exaggerated (see this abstract).

Accelerating Change Conference

Posted by Peter on September 26, 2005
Posted in: Artificial Intelligence, Health, Science and Technology, Virtual Worlds. Tagged: , , .

I was somewhat disappointed by the latest Accelerating Change Conference, which might have been great for people who have never been to that kind of conference before, but didn’t manage enough novelty to be terribly valuable to those who attended the first one. Here are a few disorganized tidbits I got from it.
Bruno Olshausen described our understanding of the neuron as pre-newtonian, and said a neuron might be as complex as a pentium.
Joichi Ito convinced me that Wikipedia has a wider range of uses than my stereotype of it as a dictionary/encyclopedia suggested. For example, its entry on Katrina seems to be a better summary of the news than what I can get via the traditional news media.
Cory Ondrejka pointed out the negative correlation between the availability of violent video games and some broad measure of U.S. crime. He hinted this might say something about causation, but reminded people of the appropriate skepticism by noting the correlation between the decline in pirates and global warming.
Someone reported that Second Life is growing at an impressive pace. I’ve tried it a little over a somewhat flaky wireless connection and wasn’t too excited; I’ll try to get my iBook connected to my dsl line and see if a more reliable connection makes it nicer.
Tom Malone talked about how declining communications costs first enabled the creation of large companies with centralized hierarchies and are now decentralizing companies. His view of Ebay was interesting – he pointed out that it could be considered a retailer with one of the largest number of employees, except that it has outsourced most of its employees (i.e. the people who make a living selling through Ebay). He also mentioned that Intel has some internal markets for resources such as manufacturing capacity.
Daniel Amen criticized modern psychiatry for failing to look at the brain for signs of physical damage. He provided strong anecdotal evidence that the brain imaging services he sell can sometimes tell people how to fix mental problems that standard psychiatry can’t diagnose, but left plenty of doubt as to whether his successes are frequent enough to justify his fees.
T. Colin Campbell described some evidence that eating animal protein is unhealthy. He didn’t convince me that he was a very reliable source of information, but his evidence against casein (a milk protein) sounded fairly strong.
One odd comment from Robin Raskin (amidst an annoying amount of thoughtless sensationalism) was that kids don’t use email anymore. They send about two emails per day [i.e. they’ve switch to IM]. The idea that sending two emails per day amounts to abandoning email makes me wonder to what extent I’m out of touch with modern communication habits.
An amusing joke, attributed to Eric Drexler:
Q: Why did Douglas Hofstadter cross the road?
A: To make this joke possible.