Mosaic genetic methods (not news)

Mosaic (genetics) – Wikipedia, the free encyclopedia.

This has been done for quite awhile but I thought I’d post about it because I think it’s a neat idea — genetically manipulate experimental subjects so that only some cells have the mutation, while others are wild-type.


When Will We Be Able to Build Brains Like Ours?

When Will We Be Able to Build Brains Like Ours? – by Terry Sejnowski –

Terry Sejnowski discusses the recent ‘catfight’ that erupted between Dharmenda Modha of IBM and Henry Markram of the EPFL over claims from Modha that his group had successfully modeled the brain of a cat.

Dr. Sejnowski provides a summary of the quest to describe the nervous system using computational models and introduces a central question: What level of abstraction is appropriate?

“Looking at the same neuron, physicists and engineers tend to see the simplicity whereas biologists tend to see the complexity. The problem with simplified models is that they may be throwing away the baby with the bathwater. The problem with biophysical models is that the number of details is nearly infinite and much of it is unknown. How much brain function is lost by using simplified neurons and circuits?”

Despite the differing approaches, both Modha and Markram say we’ll have a model human brain by 2019. Sejnowski claims that these will be impoverished brain models, “at best these simulations will resemble a baby brain, or perhaps a psychotic one”, but he does remain hopeful in his closing remarks:

“And gradually, as it increasingly mimics the workings of our brains, the world around us will become smarter and more efficient. As this cognitive infrastructure evolves, it may someday even reach a point where it will rival our brains in power and sophistication. Intelligence will inherit the earth.”

Submitted By: Dan Knudsen

The Moral Life of Babies – NYTimes

The Moral Life of Babies –

Paul Bloom talks about research on the morality of small children, and ways in which their morality is similar to and different from adults. Concise descriptions of supporting experiments is given throughout.

Basically, babies prefer nice people over mean people, but prefer people who punish mean people over people who reward mean people. But babies are not impartial; for example, they give favorable treatment to other babies who are wearing the same tee-shirt as themselves.

Also has some content about the cognition of babies in general. Experiments show that, at various young ages, “..babies think of objects largely as adults do, as connected masses that move as units, that are solid and subject to gravity and that move in continuous paths through space and time,” and “…expect people to move rationally in accordance with their beliefs and desires…”, and “…know that other people can have false beliefs”.