September 2011 Archives

David Eagleman is coming on Tuesday of this week to give a lecture, among the many things he writes about synesthesia is one. Synesthesia is the autonomic pairing of senses, a rare phenomena occurring in 1 in everyone 20-25,000 people (the current estimate is that about 1 in 23 have some light form). These correlations are most commonly seen in people who pair a letter or number to a color but cases have been reported where sounds was paired to colors, a numerical order (day of the week or the time of day) paired with personalities, or even the pairing of words with tastes. Eagleman has wrote a book entitled Wednesday is Indigo Blue and if you are interested it is available through ebrary academic complete through the library portal.

Neurologically speaking the V4 area of the brain is generally given credit for visual synesthesia but most believe it is not solely due to this area alone. Others believe the phenomena is caused by synapses not trimming enough at young ages, so the body correlates two things together that don't necessarily belong together. However, due to the large variety of synesthesia that exists it is likely we are really dealing with several different neurological happening (depending on the case) and giving them an umbrella term to function under. Genetically all forms of synesthesia are believed to be linked to a currently unknown gene as it does run in families. The gene was originally thought to linked to the X as it could skip generations but recent data has also shown cases of father to son transmission. Basically, a whole lot is known about the condition but a lot more could be known.

If you would like to read some more here a journal article, wiki link or go check out Wednesday is Indigo Blue.

When given the option of either kicking your grandmother down a flight of stairs or selling her car because you know she is too forgetful to know it was gone, one might find it difficult and uncomfortable to make a decision. Why? The question is simple, it is really only flipping a coin in many ways. In either choice grandma looses and get hurts. What about a third option where no one gets hurt, that will make this easier. So, you can kick grandma down the stairs, sell her car for your gain, or have sex with her dead body by her request. I am still finding it difficult to make a choice.

The reason pinning these questions against each other is so difficult is because they don't work on the same areas of the brain. The first example one would be causing harm, the second is being dishonest, the third fills one with disgust and all three activate separate neuropathways. After the brain has invoked all these different pathways it sends the message up to the frontal lobe so it can figure it out. As a result, we are left in conflict, mostly because we are trying to sort out all the different signals.

Carolyn Parkinson and colleagues, recently published an article that explained the differences in activation. The approached used by her team is interesting because it addresses all levels of morality, things being natural or not neutral (stealing from grandma is wrong but what about finding out you didn't pay for the dog food on the bottom of your cart once you get home.) and all the different types of situations used above.

If you would like to read about the specifics of the study including what regions were activated and how they tested the subject (some of the questions at the bottom are pretty silly), the link is posted below
MIT Press Journal

Science fiction is often more fiction than science, but when flipped fiction becomes a way broadcasting scientific facts and advancements with a cool twist, presenting knowledge with a unique and fascinating approach. Rob Spence, a Canadian film maker, does this in a video put out to promote a Deus Ex, a recently released video game. Spence draws parallels between the video game's main character who is a cyborg and where neuroscience actually is by interviewing in human cyborgs. The game is set 15 year in the future but it is not terribly far off (in a lot of respects) to things that are happening today.

The individual responsible for closer than usual understanding of science in the video game is Will Rosellini, a doctoral student at The University of Texas's neuroscience program. Rosellini who studies similar things to that in the video game and owns a company which develops medical solutions to neurological problems was a consultant to the video game and talks about the experience in an interview.

I thought the video was interesting because it illustrated some fundamentals of neuroscience in a way people with no interest in neuroscience or science could understand and enjoy. While not going too far into specifics (of the neuroscience that is) I believe the video does address the nervous system and perception as something that exists and are not separate from the body. The film maker draws a distinction between this video game and the Matrix/Inception style of science fiction which is based more on dualism than anything real. I like it when science and creativity meet and I think it is good when popular culture illustrates science as science. If you like to check out the video, it is posted below.

Duex Ex video

This week I watched a video by Ed Boyden, a neuroscientists at MIT and expert in optogenetics. Boyden's lab works on implanting optic transmitters and receivers in animal brains in order to control certain parts of behavior. The propose of this research is to discover the function of certain transmitters and how to treat disorders associated with them.
Boyden's lab starts the process by infecting an animal's brain with adeno-associated viruses (AAV) which targets certain cells and creates photoactived gated channels in the targeted cells. These channels act similar to sodium channels in that they produce an action potential but because they are photo activated, they can be stimulated by light being pumped into the brain. AAVs are useful because they act like most viruses, inserting their genetic material into the DNA of infected cell but they are not known to cause any diseases in humans, so it is safe to say this research is relent. Next, optic fibers are placed into the brain to induce the photo-stimulated cell whenever an external forces chooses (is the light on up there?). Now, a circuit has been created, on one end light that is controlled, on the other cells targeted by AAV to be stimulated.
Using these circuits Boyden's lab has reversed classical conditioning. The reversing of classical conditioning is of interest because it could be used to treat extreme phobias or more importantly to treat posttraumatic stress syndrome. The reversal is accomplished by taking whatever stimulus triggers the fear and pairing it with a flash of light in the brain triggering dopamine synapses target by the AAV, essentially rewarding the person for having experienced the stimulus. The use of this technique is really just high tech operant conditioning but is impressive because it works quickly and without electricity (which tends to favor only a few well working cells as opposed to all).
I decided to blog about this video because the class spent this week talking about ways to simplify the complexity of nervous systems. Being able to target one type of animal brain cell and stimulate it quickly and in a fairly controlled manner would enable researchers to create controls, consequently enabling the simplification of more complex brains (to some degree that is). I also found the video pretty cool and if you want to check it out the link is below.

Ed Boyden: A light switch for neurons