This is Your Brain On Awesome Thoughts on the world from a student of the mind

23Sep/10

Yaakov Stern on sleep deprivation

Here's a really interesting video on sleep deprivation as explained by Yaakov Stern, a neuropsychologist at Columbia University in New York City.

Dr. Stern is interested in investigating the interconnected nature of the brain, explaining activity and behavior by looking at how different regions of the brain communicate with one another and send information.

Everybody knows that sleep deprivation can often lead to an inability to perform daily tasks, especially mentally-demanding ones, but what kinds of processes in the brain might account for this difference in behavior?

Dr. Stern investigated this question by looking at the activity within different networks in the brain.  He recorded brain activity in a group of participants, then recorded again after they had been sleep deprived.  Interestingly, there were a few circuits that showed significantly decreased activity after sleep deprivation, and this activity correlated strongly with a decrease in performance.  Such a finding suggests that these networks might be the underpinnings of the effects that sleep deprivation has on brain and behavior.

However, he didn't stop there.  In order to answer this question more thoroughly, Dr. Stern applied a technique called Transcranial Magnetic Stimulation (TMS) to artificially stimulate these areas of the brain in sleep-deprived individuals.  Amazingly, he found that applying stimulation to the areas most affected by sleep deprivation caused a significant increase in behavioral performance on cognitive tasks, relative to those who got no stimulation.  Furthermore, the subjects that showed the sharpest reduction in activity after sleep deprivation benefited the most from this TMS treatment.  Such a finding is a rare correlation between behavior and neural activity, and it suggests a promising future for research into these neural networks.

There are a number of questions that one might ask surrounding this issue - whether other kinds of activities (such as drug use or hunger) affect these areas as well, whether we can pharmacologically increase the activity in these areas of the brain, or whether we can enact long-term changes in some other manner.  However, before embarking on these scientific inquiries, I think it best that we make sure to get a good night's sleep.

9Jul/10

How to Facilitate Motor Memory

I think this website, This Is Your Brain on Awesome, should be about getting your brain on awesome.  Almost like a how-to guide for squeezing the most out of your melon.  Usually, this would probably involve applying some sort of exogenous brain stimulation.  I'm partial to noninvasive electromagnetic stimulation myself, but to each his own.

With that in mind, here's a tip on how to get started getting your brain on awesome - shut down your prefrontal lobes when trying to learn new motor memories.

Two main categories of learning you'll often hear people refer to are declarative and procedural.  Declarative memories can be likened to facts you know about the world - for example, we all know that driving through the entire state of Kansas on I-70 is worse than Chinese water torture and the best parts of Kansas City are actually in the state of Missouri; procedural memories, on the other hand, tend to be more automated and motor in nature - like driving a car or tying your shoe.

A recent study published in the Journal of Cognitive Neuroscience (Galea et al., 2009) demonstrated that using transcranial magnetic stimulation to inhibit the dorsolateral prefrontal cortex led to increased consolidation of procedural skills.  Put more simply, what this may mean is this: by temporarily shutting down a region of the brain important for higher order cognitive function directly after performing a motor memory type task, you will see an increase in the retention of that motor memory.  The group that published the paper suggests this effect may be caused by disrupting dorsolateral prefrontal cortical functioning, which eliminates or reduces it as a resource competitor in the brain, "leaving more resources to be recruited by the procedural memory system".  By what mechanism this works isn't exactly clear, as other lines of evidence dealing with the prefrontal cortex function suggest inhibiting the prefrontal cortex could be releasing an inhibitory control that derives from that area (called disinhibition).  Regardless, the main findings still stand and make sense in light of the consolidation competition hypothesis, which suggests that memory systems interact on a competitive level with each other, especially when it comes to the consolidation stage.

So, to start getting your brain on awesome, here's what you may want to do: pull out the old guitar that's sitting in its case collecting dust, hook up some excitatory brain stimulation over your motor cortices (there is evidence this is beneficial - I'll write about those later), and practice until your fingers can't take it anymore.  Then, immediately after, apply inhibitory brain stimulation over your prefrontal cortices for a little while.  With this approach, you may be maximizing plasticity in the motor regions of the brain during skill acquisition and minimizing interference from declarative memory systems during memory consolidation.

Consider your brain juiced!  You'll be shredding like Yngwie Malmsteen in no time... but you're on your own when it comes to finding the cool outfits and necessary jewelry.