New Therapies for Stroke Victims Increase Neuroplasticity

By: Kevin O'Sullivan

            Twenty years ago, scientists believed most brain development occurred during a child’s first two years.  After a child turned two, the popular theory speculated that no new brain cells were developed, and any increase in neural function resulted from an increase in efficiency of neurological pathways. Scientists also believed that, during adulthood, the physiological structure of the brain remained mostly unchanged. Brain structure would only change after trauma to the head, poor health habits or other outside stimuli that would result in loss of brain cells. In short, popular medical theory thought the adult brain could only physiologically change for the worse.

            Today, most neurologists support the theory of neuroplasticity. By definition, neuroplasticity is the ability of the human brain to physiologically alter itself in response to stimuli. Simply, the theory suggests that our brains are physically shaped by our experiences. In theory, our brain function can not only deteriorate from our experiences, as suggested by scientists twenty years ago, but can also improve.

In the medical community, some doctors are trying to apply the theory of neuroplasticity to stroke patients.  After a stroke, one of the most common side effects in patients is loss of motor function. Upon examining an affected patient’s nervous system, doctors have found that neural re-organization has almost always occurred in patients who have lost some motor functions. If this neural re-organization were corrected, the patient could be expected to gain most, if not all, lost motor function backs.

One effective treatment doctors have found is nervous system stimulation. By administering low-volt electrical stimuli to both the brain and peripheral nervous system, doctors have found they have increased the plasticity of the neurons and improved some motor function. Why these electrical stimuli have been able to increase plasticity is not fully understood, but some scientists believe these improvements are associated with changes in synaptic activity, gene expression and increased neurotransmitter levels. With an increased understanding of neuroplasticity, non-invasive treatments reliant on electrical stimuli could become extremely effective in the near future. 

The synesthesia gene: why did it survive?

                                                                        By: Jenna Hebert

            Most of the blog’s readers have probably heard of synesthesia, a phenomenon in which “stimuli presented through one modality will spontaneously evoke sensations in an unrelated modality.” In other words, some people can see music, taste colors, and associate numbers or letters with colors. This raises some interesting questions: where did this trait come from? Why has it been conserved in the population? While it would certainly make listening to music or reading a vivid experience, synesthesia has no evolutionary advantages...right? To address this question, V.S. Ramachandran, a renowned neurologist at UC San Diego, investigated the neural basis of the disorder. He proposed that synesthesia is the result of an excess of neural connections between different modules in the brain. Supposedly, these different regions in the brain that are interconnected in the fetus do not completely separate, leading to cross wiring. While there is no definite proof that it has a genetic basis, the trait does tend to run in families suggesting that it is transmitted from parent to offspring.

Ramachandran considers several explanations for why the synesthesia gene was concerned. Since the disorder is not deleterious or advantageous, perhaps natural selection never selected for nor against the gene. It is also possible that everyone falls somewhere along a synesthesia spectrum, and those we identify as veritable synesthetes are at the tail end. A more interesting explanation considers the possibility that synesthesia might in fact be an advantageous trait. For example, the gene is frequent among artists, musicians, and other people who spend a significant amount of time on creative activities. Ramachandran suggests that because synesthesia results from cross-wiring between different modules in the brain, it is conducive to creativity and innovation. Creativity is, after all, combining ideas or things in novel ways. Another possible advantage to synesthesia is a prodigious memory. Because synesthetes associate things with more than one sense, numbers or letters are more salient. Daniel Tammet, for example, was able to memorize pi to 22,514 digits using synesthetic associations. Ramachandran also proposes that synesthetes have an enhanced sensory processing. Depending on the type of synesthesia, they perform better than control subjects at discriminating between similar colors and demonstrate increased tactile acuity. Synesthesia and its origins clearly present a fascinating mystery to neuroscientists, and I am eager to see what future research will find.

David Brang, V. S. Ramachandran. “Survival of the Synesthesia Gene: Why Do People Hear Colors and Taste Words?”

Why Doctors Should Read More Books

By: Beatriz Gadala-Maria

A not-so-recent article in the New York Times addressed a question that I think runs through the mind of most science majors, “Why the humanities?” In our fast-paced academic environment, we are quick to dismiss those classes that may seem pointless in our future careers (i.e. the infamous Writing Seminar) and tempted to fill sector requirements with easy classes that will boost our GPAs but do little for our academic growth. After all, when will a doctor incorporate classic literature into her career?

It turns out that reading novels (and even watching movies) is more beneficial than we would have imagined. It has been proven that, “individuals who frequently read fiction seem to be better able to understand other people, empathize with them and see the world from their perspective.” Movies, but not television, have a similar effect on our brains. This phenomenon is explained by an overlap that exists between brain networks used to understand stories and those used in interactions with other individuals, especially interactions that involving the thoughts and feelings of others. Stories and dramas ultimately act as simulations that help us understand the complexities of real life. This understanding can lead to greater empathy in human interactions, an important skill in any future career. For students who want to be doctors or psychiatrists, this empathy can be particularly critical in interactions with future patients.

Literature has many other beneficial and interesting effects on our brain. Besides stimulating the areas commonly associated with speech and language, such as Broca’s Area and Wernike’s Area, similes and metaphors have the power to stimulate areas in our brain associated with scent and taste, depending on what they describe. In a Spanish study conducted in 2006, when participants read words such as “coffee” and “perfume” their primary olfactory cortex (the area in our brains associated with smell) lit up in an fMRI. In another study, when participants read metaphors dealing with sensation, their sensory cortex became activated. Similarly, phrases regarding motion lead to activation of motor cortices. For our brain, these neurological events are undistinguishable from those that occur when we actually experience what we read about. Neuroimaging technology has proven that literature and fiction are more powerful than we previously could have ever imagined, making the humanities more relative to our everyday lives and future science careers than we would have previously considered. 

London taxi drivers’ memory is spectacular! Or is it?

By: Jesus Fuentes

I have always been pretty amazed with memory. Although we often forget things and are commonly limited with exact details, the mere fact that we are able to process and retain moments of our life is amazing to me. That is one of the things that drew me to neuroscience. Another thing that amazes me is people with incredible memory. A prime example is London taxi drivers, as their memorization process of the intricate streets of London stands of such great depth and complexity that is usually takes 3-4 years to complete. The process is known as acquiring “The Knowledge”.

            In the study, they sought to further investigate what seemed a contradictory result. For their incredible ability to memorize London streets and have superior navigational skills, these same drivers found significant difficulties in attaining new object-location knowledge containing a spatial component. . I learned that as the hippocampus is associated with memory, there is also a give and take with its capacity to processing new information. As the taxi driver’s acquired “The Knowledge”, there was an increase in posterior hippocampal grey matter but also a decrease in anterior hippocampal grey matter. Hence, the drivers had difficulties with anterograde memory involving spatial component. What the study proposed that there was two possibilities to the taxi drivers’ difficulties in incorporating new memory: 1) they had a general problem with forming new association in general 2) had a primary problem with processing new spatial information. Their results confirmed that compared to the controls after a variety of rigorous tests, the drivers had significantly lower results than controls in the tests regarding location-object memorization. Hence, they were able to rule out that the first possibility, but still left with many questions. However, there is still no confirming evidence that the hippocampus had a limited capacity for memory, nor a direct explanation for the give and take of memory associated with the hippocampus grey matter. As with a lot of neuroscience, there is still so much left to be discovered.

When I first read this, it seemed really abnormal. How could people with the ability to memorize something so complex have worse memory than non-taxi drivers about memorizing new things? One would think that having been able to memorize something so detailed and demanding would find acquiring new knowledge relatively easy. However, I realized it made sense in way. As amazing our brains are, there are always limitations to our natural abilities. Just as every action has a consequence, every gain has a cost. The idea and intrigue provoked by the unknown in neuroscience is amazing, and this particular example concerning hippocampus plasticity is a perfect reflection of that.

Sources Referenced:

http://journals.lww.com/neuroreport/Abstract/2012/10240/Exploring_anterograde_associative_memory_in_London.4.aspx

Get Some Sleep First

By: Helen Kim

I think many students here will be interested in the results of a new study conducted at Lancaster University. Researchers have found that sleeping on a difficult problem is actually very helpful in finding its answer. 

Details of the study and the results were published just last week in Memory and Cognition. The study was conducted on 27 men and 34 women, who were separated into three groups. First, each group was given a set of simple and difficult verbal insight problems. Then, the groups had a second attempt at the problems they could not solve. One group attempted the problems immediately after the first attempt. Another group began its second attempt after spending a period of time sleeping. The third group began its second attempt following a period of time without sleeping.

The results of the study say the group that spent some time sleeping in between the two attempts solved more difficult problems than the other two groups. However, the results also showed that sleep did not affect the number of easy problems solved.

Professor Padraic Monaghan from Lancaster’s Department of Psychology (Centre for Research in Human Development and Learning) best summarizes the significance of these results: "We've known for years that sleep has a profound effect on our ability to be creative and find new solutions to problems. Our study shows that this sleep effect is greatest when the problems facing us are difficult. Sleep appears to help us solve problems by accessing information that is remote to the initial problem that may not be initially brought to mind. Sleep has been proposed to 'spread activation' to the solution that is initially distant from our first attempts at the problem. The advice stemming from this and related research is to leave a problem aside if you're stuck, and get some sleep if it's a really difficult problem.”

So to the sleep-deprived students here at Penn, the next time you have trouble with a problem set, consider getting some sleep in, and come back when you’re refreshed and ready!

Sources Referenced:

http://www.sciencedaily.com/releases/2012/10/121012074741.htm

Orangutans With A Voice

By: Jennifer Brodsky

I went to the Philadelphia Zoo this summer and spent an hour watching the orangutans.  The young male was climbing all over his mother and swinging back and forth on a fire hose.  He reminded me of a small child and, apart from the obvious appearance differences, seemed he really could be human. 

Zookeepers have used sign language to communicate with their orangutans for some time now.  Using their hands, orangutans can express simple wants and needs.  This is no doubt fascinating, but what if we could actually communicate with them, beyond the pointing of a hand?  Well, recent studies in several zoos all over the nation suggest that we can. 

The six orangutans living in Miami’s Jungle Island use iPads to expand their vocabularies and just have a little fun!  The program’s manager, Linda Jacobs, says there were immediate positive results following the introduction of iPads.  Other than the senior orangutans who weren’t very enthusiastic, all the others have shown instant interest and understanding.  The toddlers enjoy many of the free apps that human toddlers like, such as drawing and finger painting.  The older females enjoy looking at themselves and watching videos of male orangutans.

Orangutans share 97% of our DNA and, therefore, are very closely related to humans along with Gorillas, Chimpanzees, and Bonobos.  Great apes have significantly high volumes of cerebellum, ranging from 50-70 cc compared to other monkeys who average at about 8 cc (Humans have around 140 cc).  The cerebellum is involved in movement and cognition.  As James K. Rilling explains in his essay Human and NonHuman Primate Brains: Are They Allometrically Scaled Versions of the Same Design, “Connections with motor areas would increase the speed and skill of movement, while connections with cognitive areas would improve the speed and skill of thought.” (Rilling 69).  This explains how the great apes are able to not only learn at a higher level than other monkeys, but are able to learn quickly.

Jacobs sees a bright future in the use of iPads for communication.  Using apps made for children with Autism, the orangutans are building an impressive vocabulary.  By pointing at words and pictures they are learning how to form sentences and answer questions.  Once an orangutan-proof case is found, the zoo will be able to set up screens in the enclosures and out of them, so that the public can ask questions and build a better understanding of this endangered species.  Jacobs, however, makes a point to note that the project is not for the entertainment of guests.  Orangutans have proven themselves very intelligent, and they need mental stimulation to keep busy.  Through this enrichment we may just find that these great apes have a lot to say.

http://www.youtube.com/watch?v=3KGrXZ5pWko

Sources used:

http://tampa.cbslocal.com/2012/05/09/orangutans-at-miami-zoo-use-ipads-to-communicate/

http://courses.biology.utah.edu/bramble/5360/readings/rilling_06.pdf