How the brain works

Last month I reported on a finding that estrogen acts through calpain, a protein crucial to learning and memory, that acts as a neurotransmitter in the brain. Now a new study has found that BDNF activates calpain, and when it does, the spine structure changes in ways similar to those that occur during learning. When activation was blocked with calpain inhibitors, the addition of BDNF had no effect. All this implies that all the great benefits of BDNF for learning and memory are in fact due to calpain.

A paralyzed patient implanted with a brain-computer interface device has allowed scientists to determine the relationship between brain waves and attention. Recordings found a characteristic pattern of activity as the subject paid close attention to the task. High-frequency beta oscillations increased in strength as the subject waited for the relevant instruction, with peaks of activity occurring just before each instructional cue.

Why do women tend to be better than men at recognizing faces? Two recent studies give a clue, and also explain inconsistencies in previous research, some of which has found that face recognition mainly happens in the right hemisphere part of the face fusiform area, and some that face recognition occurs bilaterally. One study found that, while men tended to process face recognition in the right hemisphere only, women tended to process the information in both hemispheres.

A rat study has revealed that as the rats slowly learned a new rule, groups of neurons in the medial frontal cortex switched quite abruptly to a new pattern corresponding directly to the shift in behavior, rather than showing signs of gradual transition. Such sudden neural and behavioral transitions may correspond to so- called "a-ha" moments, and support the idea that rule learning is an evidence-based decision process, perhaps accompanied by moments of sudden insight.