Category: Brain Science

Recent research published in the September 3, 2010 issue of Science shows that social cliques (clustered ties with a high degree of separation between clusters) are more effective at spreading behaviors across social networks than less tightly knit social groups that provide shortcuts across social space.

This finding is surprising since you might think that behavior would spread faster the broader the individual contacts across social space. On the other hand, a social clique is natural for a human so perhaps it’s not surprising that it’s optimal for spreading behavior (assuming that spreading new behaviors as rapidly as possible improves the chances for survival).

The paper, titled “The Spread of Behavior in an Online Social Network Experiment,” also reported that adoption of a behavior became increasingly likely the second, third, and fourth time an individual received a recommendation from a social network friend. More recommendations didn’t affect adoption.

Wouldn’t it be interesting to see if those with really large clusters of social network friends (for example, individuals with thousands of Facebook friends) move out of the optimal social clique configuration. Perhaps collecting as many social network friends as you can get changes recommendations into noise?

It seems reasonable to assume that two minds working to solve a problem are better than one. Recent research published in a paper titled “Optimally Interacting Minds” in the August 27, 2010 issue of Science calls this assumption into question.

The research showed when two people with similar abilities collaborate through communication that indeed they do perform better than either one would on their own. However, when the two people have different abilities the collaboration performs worse than the best performer would on their own.

This suggests that you should not try to solve a problem as a team with a person with lesser or better abilities than you have. If you’re working on a problem team up with someone with similar abilities. Otherwise, delegate the problem to someone with better abilities.

Three recently published papers provide data for building models of whisker related thalamocortical input to excitatory neurons in a cortical column of rat primary somatosensory cortex. All three papers were published in the October 2010 issue of Cerebral Cortex.

The first article in the series “Dimensions of a projection column and architecture of VPM- and POm-axons in rat vibrissal cortex” describes the spatial distribution and anatomical dimensions of thalamocortical input to the primary somatosensory cortex.

The second article in the series “Number and Laminar Distribution of Neurons in a Thalamocortical Projection Column of Rat Vibrissal Cortex” presents the dimensions of a whisker related thalamocortical projection onto rat primary somatosensory cortex. In addition, the paper provides estimates of the number of excitatory and inhibitory found within the volume of the thalamocortical projection and within each of the layers of the cerebral cortex. Finally, the authors provide an estimate of the number of action potentials elicited in this volume of cortex during the first 50 ms and 100 ms after stimulating a whisker.

In the third and final article in the series “Cell Type–Specific Thalamic Innervation in a Column of Rat Vibrissal Cortex” the authors provide quantitative estimates of the amount of synaptic input from specific thalamocortical projections onto specific excitatory neuron types in the rat primary somatosensory cortex.

These data will be very useful for those building computer models of the whisker related rat thalamicortical projections and primary somatosensory cortex.

Other related blog posts:

Wiggling Whiskers for a Living?

Wiggling Whiskers: Directional Tuning