17th Joint Symposium on Neural Computation – UCLA
Saturday, May 22, 2010
9:00 am – 5:00 pm
Registration: $35 http://www.jsnc.caltech.edu/
Want to run your research computations on Amazon’s cloud computing service?
No word as to when the next grant applicatiion deadline is, but it looks like an ongoing program.
Thanks to Brad Aimone, who got about $3000 worth of compute time for his research project, for alerting us to this.
When we learn new information we use only a tiny fraction of the neurons in our brain for that particular memory trace. In order to allow the molecular study of those specific neurons we combined elements of the tet system with a promoter that is activated by high level neural activity (the cfos promoter) to generate mice in which a genetic tag can be introduced into neurons that are active at a given point in time. The tag can be maintained for a prolonged period, creating a precise record of the neural activity pattern at a specific point in time. Using fear conditioning we found that the same neurons activated during learning were reactivated when the animal recalled the fearful event. We also found that these neurons were no longer activated following memory extinction, consistent with the idea that extinction modifies a component of the original memory trace.
Replay of behavioral sequences in the hippocampus during sharp wave ripple complexes (SWRs) provides a potential mechanism for memory consolidation and the learning of knowledge structures. Current hypotheses imply that replay should straightforwardly reflect recent experience. However, we find these hypotheses to be incompatible with the content of replay on a task with two distinct behavioral sequences (A and B). We observed forward and backward replay of B even when rats had been performing A for >10 min. Furthermore, replay of nonlocal sequence B occurred more often when B was infrequently experienced. Neither forward nor backward sequences preferentially represented highly experienced trajectories within a session. Additionally, we observed the construction of never-experienced novel-path sequences. These observations challenge the idea that sequence activation during SWRs is a simple replay of recent experience. Instead, replay reflected all physically available trajectories within the environment, suggesting a potential role in active learning and maintenance of the cognitive map.
CNN News ran a segment last month on the meaning and impact of intelligence on a person’s life, as measured through a test such as the Wechsler Adult Intelligence Scale which gives an “IQ.” Dr. John Gabrieli of MIT displays brain scans that show functional differences between brains of low IQ and high IQ subjects while completing intelligence tests in an MRI scanner. The higher IQ brain shows less activity than the lower IQ brain during the same task, indicating that smarter brains are more efficient.
The findings on IQ mentioned in the report are remarkable. The standing debate on the importance of IQ is also on display here. Researchers have found that 25% of what makes one successful can be attributed to IQ -but Dr. Gabrieli points to findings that increases in IQ are linked to “a better paying job, a healthy future, more stability in your family life.” This makes the prospect of “training intelligence” to increase IQ scores all the more alluring and relevant. A demonstration of a computer working memory task that is used to “train intelligence” is featured in the segment.
Watch the segment here:
Read more about the working memory task featured in the segment:
-A Neurodudes Reader