One Week of Developing Intelligence

I have been meaning to comment on some of Chris Chathams' postings this week, so now that I have a moment, I will take the time to comment on the entire week of develintel posts.

Monday, March 27: Roboticist Mark Tilden currently works for Wowwee Toys. Prior to working in the toy business, however, Mark led quite a different life: as a physicist at the Defense Department's Los Alamos National Laboratories, he was responsible for building autonomous, distributed and parallel-processing robots. Mark also worked at NASA, where he seems to have been intimately involved in the design of the Mars rovers.

A dominant theme in Mark Tilden's robotics research is embodiment. Many of his robots don't possess a central microprocessor - instead, they rely entirely on the non-linear coupled oscillations of electrical activity between as few as 12 transistors, connected in parallel. These patterns drive activity in the sensor and motor layers, and are "constantly attempting phase lock synchronization among variable pulse trains," according to Tilden's 2003 article in Robotics and Autonomous Systems. Read more at the source.

Tuesday, March 28: Today, Chris reviewed the book "The Three Pound Enigma" by Shannon Moffett. Unlike so many popular science books, "The Three Pound Enigma" has something for novices and experts alike. Clear explanations of everything from fMRI technology & K-complexes to anterograde amnesia & dissociative identity disorders will dazzle the layperson, and yet Moffett also provides something for the professional audience: a glimpse into the personalities of some of the field's most successful scholars, sufficiently detailed to give additional insight on their (in)famous theoretical perspectives. Read the rest of Chris' review here.

Wednesday March 29: Today, Chris looks at the way that the brains of more intelligent children (IQ 121-145) develop over the childhood and early adolescent years. .... the developmental trajectory of thickness changes are significantly related to IQ, such that those with the highest IQs (121-145) show an initial reliatively thin cortex, which rapidly thickens, and then thins again by 11 or 12 years of age.

"Brainy children are not cleverer solely by virtue of having more or less gray matter at any one age. Rather, IQ is related to the dynamics of cortex maturation,” said Rappoport, one of the authors on the study. A similar sentiment was expressed by Shaw, the lead author: "The story of intelligence is in the trajectory of brain development.” This relationship was strongest for prefrontal cortex thickness, which is often thought to be the seat of planning, strategizing, and other "executive functions."

Thursday March 30: Today, Chris elaborates on the ideas introduced yesterday, on neuronal proliferation and pruning. ....the best pruning strategy is actually advantageous as compared to a fully connected "infant" network. In other words, an optimally pruned network will have more neurons than an unpruned network, although they both have roughly the same number of synapses or amount of synaptic efficacy.

....In botany, pruning induces "rejuvenation" at the pruned nodes. Perhaps neural pruning results in an overall decrease in cortical thickness, which is equivalent to why pruned plants will receive more sunlight, and yet also increases the efficacy of existing circuits, in the same way that pruned plants will yield more flowers and fruit. Read more here, including Chris' suggestions for utilising the pruning concept in artificial intelligence research.

Friday, March 31: Today, Chris presents a wrap-up of brain blogging for the week from other blogs (including the ever humble Al Fin). From brain-machine interfaces, to transcranial magnetic stimulation, to the double deficit of dyslexia, Chris summarizes the brainblog scene for the last week of March.

That was a very good week of developing intelligence, courtesy of Chris Chatham. But then, you will find the same high quality of reporting on cogsci topics from Chris pretty much every week.