Archive for the ‘At the scale of one or more individuals’ Category

Forest for the trees?

Monday, April 17th, 2006

On Making the Right Choice: The Deliberation-Without-Attention Effect — Dijksterhuis et al. 311 (5763): 1005 — Science

I don’t know quite what to make of this. In fact, I just don’t understand what is going on. But I can definitely think of examples from my own life where this is true. Sometimes not thinking about a problem really does lead to its solution and it’s fascinating to think about why this may be.

Also, the authors draw a connection between what they call unconscious thought (as performed in their experiments) and insights that can come “after sleeping on it”; I’m not sure these phenomena are the same. I think sleep taps into deeper organization processes that are not available on the timescale of unconscious thought, as given in the experiment.

Abstract:

Contrary to conventional wisdom, it is not always advantageous to engage in thorough conscious deliberation before choosing. On the basis of recent insights into the characteristics of conscious and unconscious thought, we tested the hypothesis that simple choices (such as between different towels or different sets of oven mitts) indeed produce better results after conscious thought, but that choices in complex matters (such as between different houses or different cars) should be left to unconscious thought. Named the “deliberation-without-attention” hypothesis, it was confirmed in four studies on consumer choice, both in the laboratory as well as among actual shoppers, that purchases of complex products were viewed more favorably when decisions had been made in the absence of attentive deliberation.

Newsome Wants Electrode In Own Brain

Wednesday, February 15th, 2006

Stanford Neuroscientist Bill Newsome wants to implant an electrode in his own brain to study consciousness in ways that would be difficult with volunteer human subjects.

When considered alongside the story of Kevin Warwick who had a 100-electrode array implanted in his arm in 2002 in order to study electrical signals from his hand, one must wonder: is this a starting trend?

From the article:

TR: Do you really want to do this?

BN: Well, I’ve thought about it very carefully. I’ve talked to neurosurgeons, both in the United States and outside the country where the regulatory environment is less strict, about how practical and risky it is. If the risk of serious postsurgical complications was one in one hundred, I wouldn’t do it. If it was one in one thousand, I would seriously consider doing it. To my chagrin, most surgeons estimate the risk to be somewhere in between my benchmarks.

–Stephen

Personality in animals

Sunday, January 22nd, 2006

The Animal Self - New York Times

Interesting read on the return of personality psych (and the use of the term “personality”) to ethology.

Some tidbits:

It was back in 1991 that Anderson and Jennifer Mather, a psychologist from the University of Lethbridge in Alberta, Canada, first decided to undertake a joint personality study of 44 smaller red octopuses at the aquarium as a way to begin to codify and systematize what they thought they had been observing. Using three categorizations from a standard human-personality-assessment test - shy, aggressive and passive - their data would ultimately show that the animals did consistently clump together under these different categories in response to various stimuli, like touching them with a bristly test-tube brush or dropping a crab into the tank.

“The aggressive ones would pounce on the crab,” Anderson told me. “The passive ones would wait for the crab to come past and then grab it. The shy animal would wait till overnight when no one was looking, and we’d find this little pile of crab shell in the morning.”

Anderson and Mather’s resulting 1993 paper in the Journal of Comparative Psychology, entitled “Personalities of Octopuses,” was not only the first-ever documentation of personality in invertebrates. It was the first time in anyone’s memory that the term “personality” had been applied to a nonhuman in a major psychology journal.

And,

Alison Bell has done related experiments with sticklebacks. It has long been clear to researchers that fish that have lived for many generations in the proximity of dangerous predators are less bold and less aggressive than animals that have lived relatively risk-free. What Bell discovered is that those cautious tendencies outlast the presence of risk, even by a generation. When she moved sticklebacks who had always lived in a high-risk environment into a low-risk environment, she found that not only did they retain their cautious tendencies, but so did their offspring. Even fish raised from birth in a low-risk environment behave more fearfully if raised by a particularly vigilant father from a high-risk background.

“There’s definitely the effect of genetic difference,” Bell explained, “but there’s also the effect of what is experienced as they grow up. Genotype and environment interactions make it difficult to detect the effects of genes, because you have to take the environment into account. This is annoying to geneticists.” To scientists like Bell who are studying the interplay of genes and environment, however, it is of profound interest.

When Bad People Are Punished, Men Smile (but Women Don’t)

Sunday, January 22nd, 2006

When Bad People Are Punished, Men Smile (but Women Don’t) - New York Times

I think there has been studies similar to this before… here’s the relevant details:

Furthermore, researchers found that the brain’s pleasure centers lit up in males when just punishment was meted out.

The researchers cautioned that it was not clear if men and women are born with divergent responses to revenge or if their social experiences generate the responses.

fMRI evidence that human brain has (functional) small world properties

Wednesday, January 11th, 2006

A Resilient, Low-Frequency, Small-World Human Brain Functional Network with Highly Connected Association Cortical Hubs (Achard et al., 2006)

A study on network properties of the whole brain (functional connectivity data from fMRI)… interesting to see this type of work published in J. Neurosci. Building on previous fMRI/whole brain connectivity studies, the authors use a set of wavelet basis functions to estimate the correlations between different anatomical regions.

Also includes some analyses on resiliency of the system (via a metric like “largest connected cluster”) to random and targeted attack (ie. node deletion). It would be neat if they also did some analysis of common stroke damage. I would think that a stroke probably doesn’t qualify as a “targeted attack”, in the traditional sense, but, due to the predefined structure of the major circulatory structures (eg. circle of Willis), there are likely regions that are near the most commonly blocked arteries, etc. Perhaps someone with some medical qualifications could weigh in here?

There is also a nice discussion of why the human brain does not appear to be a scale-free network: That nodes do not seem to follow the “rich-get-richer” rule of preferential attachment. Evolutionarily recent structures like prefrontal seem to be among the hubs of the system and older structures like limbic regions do not dominate. Here’s a picture of the connectivity map from the paper:
Connectivity map

Full abstract after the jump.
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The Most Dangerous Idea (Apparently)

Friday, January 6th, 2006

So, Edge has a new question for 2006 for its All-Stars of Academia to answer: What is your dangerous idea? (Suggested to Edge by Steven Pinker, who perhaps got the idea from a colloquium series at his old haunting grounds.)

Offhand, one might expect a broad range of perceived dangerous ideas, varying by research interests and such. What’s surprising is that many of the luminaries think that the “most dangerous idea” is this particular, same idea: As neuroscience progresses, popular realization that the “astonishing hypothesis” — that mind is brain — will create a potentially cataclysmic upheaval of society as we know and have profound (negative) moral implications as people claim less responsibility for their actions.

Of course, this just isn’t true. But, would you believe that
Paul Bloom,
VS Ramachandran,
John Horgan,
Andy Clark,
Marc Hauser,
Clay Shirky,
Eric Kandel,
John Allen Paulos,
and, in a more genetic context, Jerry Coyne and Craig Venter
are all very worried about this issue? (And I didn’t even read 50% of the Edge dangerous ideas… there might be even more… ) Is this really the most dangerous idea out there to all of these talented thinkers?

I feel strongly that science and morality have always been separate domains and that any worry that, by “debunking” the mind, we automatically become immoral machines is just ridiculous. Through this scientific knowledge, we might gain some humility, maybe better see our close relatedness to nonhuman primates and place in nature, etc., but we’re not going to flip out and become crazed zombies. This just isn’t going to happen.

Does anybody else think that this just isn’t a truly dangerous idea (although certainly an “astonishing” one, in the Crick sense)? Or am I wrong here?

Samples of academic worrying after the jump.
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Humans imitate humans more than chimps do

Wednesday, December 14th, 2005

This nytimes article describes an experiment in which

1) In front of chimps, human researchers demonstrate opening a box, but they throw in some unnecessary steps. The box is constructed so that an onlooker can figure out which steps are unnecessary just by watching. The chimps learn to open the box, but skip the unnecessary steps.
2) In front of human children, the researchers do the same thing. The children learn to open the box, but are careful to do exactly what the demonstrator did, including the unnecessary steps.

The children’s awareness of which steps were unnecessary in condition (4) is shown by having some children who do not get to see a demonstration of how to open the box. These children are able to figure out how to open it (without the unnecessary steps, of course).

Thus, human children, as compared to chimps, are more likely to imitate exactly what they see.

Victoria Horner, Andrew Whiten. Causal knowledge and imitation/emulation switching in chimpanzees (Pan troglodytes) and children (Homo sapiens), Animal Cognition, Volume 8, Issue 3, Jul 2005, Pages 164 - 181

Bees Recognize Human Faces??

Tuesday, December 13th, 2005

This is really weird!

Somebody debunk this before it blows my mind.

–Stephen

His Holiness’s Message: Better living through chemicals (or electrodes)

Saturday, November 12th, 2005

His Holiness has spoken. He wants neuro-drugs to take and electrodes stuck in his brain so that he doesn’t have to spend hours meditating each day. (Enlightenment now!) If you want to do hot stuff, study physics or brain science. His interest in neuroscience stems from a long-standing interest in body hair. Yes, body hair. Americans need to figure their own way through this whole intelligent design business. Not all antidepressants are alike; for instance, the Dalai Lama is against tranquilizers. Definitely against tranquilizers. And, perhaps most surprisingly, His Holiness, approves of animal research — when it’s done right and with respect.

Minute-by-minute liveblog follows after the jump.
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On the function of sleep

Tuesday, November 8th, 2005

The nice NYT article on the function of sleep follows on a recent NIH-funded Nature insight series.

Some interesting facts from the NYT article:

  • Sleep patterns vary greatly. Some bats sleep 20 hours, giraffes get 2 hours. (hmmm… grad students might be evolving toward giraffes…)
  • Sleep has recently been found to occur in invertebrates too. Alternatively stated: Sleep is evolutionarily very old.
  • Slow wave sleep is also found in fruit flies. (Divergence from fruit flies for us was 600 million years ago.)
  • Some people don’t have any REM sleep. Behaviorally, these people are entirely normal, implying that it’s purpose might not be as obvious as one had thought (ie. required for the preservation of new memories, etc.)
  • If you put a bunch of ducks in a row, the ones on the inside will sleep more often with both eyes closed. The ones on the outside will sleep with one eye open and it is (always?) the eye facing outward from the huddle. They are able to “sleep” one half of the brain at a time and, apparently, this sleeping with one eye open was lost in higher mammalian evolution. Fascinating.