Archive for the ‘Networks’ Category

Determining research trends from Neuroscience abstracts

Wednesday, October 17th, 2007

In this paper at arXiv, Yin et al. report on an analysis of the abstracts from the SfN meetings from 2001 to 2006. It sounds like their analysis uncovered several interesting trends: Two they mention in their abstract are that 60% of authors appear in only one year’s abstracts over the studied period, and that systems neuroscience seems to be on the rise relative to cellular and molecular neuroscience.

-John O’Leary

Age-dependent brainwashing in bees

Monday, July 23rd, 2007

Apparently, when not busy blowing our minds, bees occupy themselves by…

…brainwashing their youth

…and/or mysteriously disappearing from the face of the earth

Keeping an eye on species poised to take over the world,
Davie

Williams syndrome nytimes article

Monday, July 9th, 2007

http://www.nytimes.com/2007/07/08/magazine/08sociability-t.html

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WNYC’s Radio Lab is Back for Season 3

Monday, May 14th, 2007

Read on for a guest-posted ad for WNYC’s radio lab (http://www.radiolab.org)

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A ubiquitous human parasite that shapes human culture?

Thursday, August 10th, 2006

In the provocative-hypothesis-of-the-week department:

Kevin Lafferty, a parasitologist, has put forth the idea that a fairly ubiquitous parasite (infecting O(10%) of Americans, and up to 2/3 of people in places like Brazil) is responsible for some of the diversity of human culures (1). The parasite uses common housecats to increase its transmission to the next host in the life cycle, and has a subtle effect on human personality, with some studies claiming that it even causes neuroticism, and even schizophrenia. (One clinical report (2) claims that “subjects with latent toxoplasmosis had higher intelligence [and] lower guilt proneness.” Hmm!)

Anyway, Lafferty noted that toxoplasmosis varies in prevalence from world region to world region, and then tries to draw correlates between these prevalences and local cultures:

“Drivers of the geographical variation in the prevalence of this parasite include the effects of climate on the persistence of infectious stages in soil, the cultural practices of food preparation and cats as pets. Some variation in culture, therefore, may ultimately be related to how climate affects the distribution of T. gondii, though the results only explain a fraction of the variation in two of the four cultural dimensions, suggesting that if T. gondii does influence human culture, it is only one among many factors.”

I wonder how one could test this hypothesis? Look for recent immigrants from one culture to another, who have lower Toxoplasmosis incidence? (Preferably finding populations that go in opposite directions, as a control.) Track culture change vs. migration vs. climate change?

Unlikely, perhaps. But nice that people are still thinking big :)

Ed

(1) Lafferty, K
Can the common brain parasite, Toxoplasma gondii, influence human culture?
Proceedings of the Royal Society B: Biological Sciences
doi:10.1098/rspb.2006.3641

Picked up by the popular press here

(2) Flegr J, Havlicek J.
Changes in the personality profile of young women with latent toxoplasmosis.
Folia Parasitol (Praha). 1999;46(1):22-8.

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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Neuroscience family tree

Tuesday, November 1st, 2005

Some folks have created NeuroTree to document the advisor-advisee relationships (i.e., “so-and-so was a grad student of that guy, and that guy postdoc’d with someone else”) of neuroscience. With this information, one can draw “family trees” like this.

Here is the FAQ.

Importantly, this is a collaborative effort, so add your name if it’s not there already.

-John O’Leary

Evolutionary psychology of gossip

Wednesday, August 17th, 2005

Have You Heard? Gossip Turns Out to Serve a Purpose - New York Times

From the article:

Gossip not only helps clarify and enforce the rules that keep people working well together, studies suggest, but it circulates crucial information about the behavior of others that cannot be published in an office manual. As often as it sullies reputations, psychologists say, gossip offers a foothold for newcomers in a group and a safety net for group members who feel in danger of falling out.