Brownian thought space

Cognitive science, mostly, but more a sometimes structured random walk about things.

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Location: Rochester, United States

Chronically curious モ..

Monday, October 23, 2006

The Gender force

More and more it's becoming clear that stereotypes can have pretty nasty and insidious effects. It's quite one thing to say that there are, e.g., sex differences, and quite another to ask where they come from. Here's my basic philosophy: there cannot be any assumption of a difference at the individual level, even if there is any amount of evidence to the contrary at the population level. Think of it this way: if you look at the 1000 fastest times in the 100m dash, the 1000th fastest man (10.08 sec) is faster than the fastest woman (10.49 sec). So, if tomorrow you went to your local race track and there was one man racing one woman, whom would you bet on? If you were a little cautious, you might first try to find out what happened in past encounters; nothing ensures that that particular man is faster than that particular woman. Basically, what it boils down to is not having prejudices. Anyhow; one of the things about prejudices is that they can act against you: you classify yourself as type X, and behave as befits X. But it appears that not everyone believes this Insidious Theory of Stereotypes, so its nice to see a paper that shows this in an interesting way: Ilan Dar-Nimrod and Steven Heine at the U. British Columbia gave women 2 GRE-like maths tests, with a GRE-like verbal test squeezed between the two. The first maths test was a baseline for basic abilities. The comprehension test was the independent variable, with 4 groups: (G): said that sex differences in math abilities were due to genetic reasons, (E) said they were due to experiental factors, (S) talked of gender differences without referring to maths and (ND) talked nothing about sex differences. The dependent variable was the score in the 2nd maths test, corrected by the scores in the first. Women score worse on the 2nd test if they study passages relating to gender differences in general (S) than to gender-unrelated passages (ND). The interesting thing is in the two other groups: in the genetic-cause group (G), women perform as bad as in the S group; but in the experiental cause (E) group, women perform better: as in the ND group. What's nice is that while reading about gender differences in general or those related to math abilities in a genetic context are "bad", reading about differences for maths because of experiential effects actually result in better scores. It's as if the women think that if it's up to different experiential factors, it cannot be generalized. But what's a bit strange is that the authors conclude that mere exposure to scientific theories of gender differences (e.g. genetic causes) might be bad. But that doesn't explain why there are no differences between the G and S groups. Here's a possibility: according to the Insidious Theory of Stereotypes, identifying with a group and having a stereotype for that group is deleterious if you yourself are part of said group. But, there is an ameliorating effect if you then realize that the bad things happen not across the board, but in that subset categorized by, (in this case, for example,) different experiential factors. So, for me the message is not that scientific studies should be treated with caution etc. It's that the Insidious Theory is everywhere. As for treating scientific theories; mankind will just have to realize that even if homosexuality is (relatively) rare and rape is (relatively) common in the mammalian lineage, this scientific fact has no place in the functioning of the human society any more than does the fact that salt typically has a cuboid structure ad is made up of Na+ and Cl-... *** Ref: Ilan Dar-Nimrod and Steven Heine, (Oct 2006). "Exposure to Scientific Theories Affects Women's Math Performance" Science 314(5798), pg. 435

Wednesday, October 18, 2006

Glia in the nervous system

In a previous post I was wondering about the glial cells. Glial cells outnumber neurons 10-1 in the brain. The traditional view has been that glia are support cells, feeding and nourishing the real computing babies, the neurons. But, as even wikipedia says, the only noticeable difference is that they don't produce action potentials. And a recent review* in Current Opinions in Neurobiology has this to say:
Studies of C. elegans have revealed a connection between glial ensheathment of neurons and tubulogenesis, have uncovered glial roles in neurite growth, navigation, and function, and have demonstrated roles for glia and glia-like cells in synapse formation and function.
That's some more reason to think that simply considering the neurons for computing might be plain wrong. And what about stuff like input-driven plasticity? What role do glia play in that? I think it's too early to say, but it's not so far-fetched to imagine that glia might actuallyplay a role in setting up the initial structures in the brain...

Monday, October 16, 2006

Thesis Submitted!

Thursday, October 12, 2006

Chewing Gum experiment

Was (re)looking over the baby-sign language-babbling experiments by the group of Laura Ann Petitto at Dartmouth and I thought of a kooky expeirment to show that speaking recruits the left hemisphere in adults.
  • Give a bunch of people chewing gum, to chew
  • Get them to do some kind of task (like the Map Task?) which involves verbal and non-verbal communications.
  • Measure where the gum is during bouts of (1) verbal communication (2) non-verbal communication
The hypothesis predicts that during the verbal communication phase, the gum will be on the left side of the mouth... Simple. Direct. Easy to do. If you do do the experiment, I want authorship or I sue your @$$ ps: The exact route from the babbling babies to the C.G. Experiment is tortuous and I cannot recreate it. Here is a very cute baby video from supplementary material for one of these experiments.

Monday, October 09, 2006

Millenium scientists - India

Found this article from the December 27 issue of India Today, with the scientific Faces of the Millennium. The great thing at that time was how many people I knew, and how:
  • (1) Partha Majumdar - ISI, Calcutta; met at a conference on Mathematical Biology, Puri
  • (2) Jayant Udgaonkar - faculty at NCBS
  • (3) Samir Brahmachari - taught us molecular biophysics at the MBU, IISc
  • (4) Milind Watve - head of microbiology at Garware College, Pune, and partially to blame for my entering science.
  • (5) R Sukumar - my Ph.D. advisor at the CES, IISc
  • (6) Raghavendra Gadagkar - taught us behavioural ecology at the CES, IISc
  • (7) N. Balakrishnan - head of the SERC, IISc
So that's how I knew I was in good company.... :)

Friday, October 06, 2006

Microbiology, Garware College...

More pictorial evidence


Verbroke, n.: To not have anything to say, as in "I'm verbroke." Another new word, coined spontaneously in the context of a conversation with Pari.P.

Tuesday, October 03, 2006

Thesis: The Jury is formed

Help. Things are moving along, and it's getting scary down here. So the jury lineup looks like this:


Dick Aslin, Anne Christophe, Marina Nespor


Jacques Mehler, Tim Shallice, Mathew Diamond

Pierre Paul Broca

That's the man. And here's the article about Tan, on the superb Classic in the History of Psychology. Thanks Chris Green!