It looks like my goal of world domination have gotten a few steps closer, if two of the popular press articles I posted in the webliography are any indication.

The two articles form a theme of sorts about control.  One of the articles talks about how scientists hacked into a monkey’s brain to control its movements.  There have been reports in the literature describing procedures by which monkeys can control objects in the real world with their brains.  This is usually achieved by an implant of some sort that can be affected by certain patterns of electrical activity in the surrounding brain tissue that then sends a signal to a device in the real world.  This research seems promising for a variety of things, particularly people with paralysis or prosthetic limbs,   Imagine being able to control the prosthetic not only with the muscles near it, but also with your brain to some extent.

Schematic of brain showing the ventral tegmental area (VTA).

Schematic of the brain showing the ventral tegmental area.

Researchers have figured out an elegant way to influence the decision making process of monkeys.  They implanted electrodes into the ventral tegmental area (VTA) of the brain, which is one of the places (as you will learn more about in the coming weeks) that produces dopamine and is involved in reward circuitry of the brain.  Then, they conducted a simple preference test by showing monkeys two pictures of random objects and had them indicate which one they liked better.  This initial preference test was their control procedure since they were interested in what choices the monkeys made without any interference from the experimenters.  Once this was done, they demonstrated that by sending brief electrical bursts through the electrodes implanted in the monkeys brains the researchers could get the monkeys to reliably switch their preferences for pictures.  Now, this doesn’t mean an evil mustache-twirling mastermind, or the government, or the NSA are going to take over your mind or anything like that, though that possibility is certainly there.  But this does build on some fascinating research from the 1950s that helped to further our understanding of the role the brain plays in motivating our specific choices.  The fact that this can be manipulated artificially is an interesting finding.

Long-term potentiation

A schematic of a regular synapse and one that has undergone stimulation to produce a long-term potentiation (LTP).

In the other interesting article, researchers were able to turn memories off and on.  This was done in genetically engineered rats using light pulses that strengthened or weakened synapses in the hippocampus.  This is another thing you’ll be learning about (in Week 5 I think).  One of the amazing things about our nervous system is that it is dynamic and is constantly changing due to our experiences.  It’s why we can learn new things.  One of the ways memories are formed is through strengthening and weakening of synapses, or long-term potentiation (LTP) and long-term depression (LTD).  This strengthening and weakening can be achieved through everyday use, such as when you memorize information for this class, or become classically or operantly conditioned to perform a response to a specific stimulus.  It can also be artificially induced, using different frequencies of light pulses that stimulate the synapse.  If you can find the right frequency of pulses (high or low) you can make the synapse stronger or weaker.  This is the mechanism by which the researchers in this particular study were able to manipulate memory in the rats. They were able to turn a conditioned fear off and on using light pulses to the hippocampus.

Both of these studies are interesting for a couple of reasons.  First, they tie together a lot of the information you’ve already learned in the course, particularly how synapses and neurotransmitters work, as well as brain structure (VTA and hippocampus) and shows how they all work together to produce complex behavior.  The added layer that makes this particularly fascinating to me is the fact that researchers can control behavior through selective brain stimulation, an idea that is exciting and a little terrifying.  I will admit it does conjure up images of a MatrixThe Matrix-like culture where people’s thoughts and behaviors are controlled by others by directly accessing their brains.  It’s easy to see how something like that could be abused at some future point, though we’re a long way from that.

I can see some tremendous potential for good, here, too.  In particular, imagine what the treatment of extreme phobias, Alzheimer’s disease, PTSD, and other types of problems related to memories would look like if we had the ability to either enhance memories or take some memories away at will.  It’s tempting to shrink from an idea like that, because our memories are what make us who we are, and common sense tells us we might be better off learning to just cope with them.  But imagine memories so awful, so debilitating and disturbing, that it becomes difficult or impossible to cope with them, and they begin to affect every aspect of your life.  I’ve never suffered from PTSD, but I imagine it can be quite horrible, and if conventional treatment doesn’t help then perhaps being able to suppress the memories, at least for a little while so that other coping mechanisms can be acquired and strengthened might offer some people a desperately needed reprieve.  And being able to counter the synapse weakening amyloid beta proteins in the brains of people with Alzheimer’s Disease seems like a promising idea worth investigating.

It’s a little harder to see the benefits of influencing choice.  One can easily envision unscrupulous advertisers using something like this to force people to choose their products, but again, I doubt that would ever happen.  I think the significance of this centers on the issue of motivation.  They were able to manipulate motivation, and got monkeys to choose things they might not otherwise choose.  Though it’s a stretch, this might be something beneficial to people suffering from depression or inactivity of one sort or another.  The idea is interesting, anyway. I wouldn’t mind being able to give my brain a little zap to get me motivated.

References

Arsenault, J.T., Rima, S., Stemmann, H., Vanduffel, W. (2014). Role of the primate ventral tegmental area in reinforcement and motivation.  Current Biology, 24(12), 1347–1353 DOI: http://dx.doi.org/10.1016/j.cub.2014.04.044

Nabavi, S., Fox, R., Proulx, C.D., Lin, J.Y., Tsien, R.Y., and Malinow, R. (2014). Engineering a memory with LTD and LTP.  Nature, doi:10.1038/nature13294

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