Brain in Numbers for the Visuals

Who Has the Biggest Brain?

Here is a cute and addictive game that challenges your logic, memory, visual and your mathematic abilities.

Of course, this is not scientific and the score you get is arbitrary. However, even though it is just for fun, some of the games are variants of some valid neuropsychological tests I've encountered.

List of biggest brains:

You can try to guess which brain is from what animal on this website: Neuroscience for Kids - Brain Comparisons

Brain and Body Sizes

Evolution & the Brain

List of biggest brains proportional to the body:

Sources:

http://www.playfish.com/?page=game_braingame

http://faculty.washington.edu/chudler/compare2.html

http://serendip.brynmawr.edu/bb/kinser/Size1.html

The Musical Brain: Review of a Documentary

I just watched a documentary on CTV at 7h00 PM called "The Musical Brain". It was a very touching and smart introduction on the purpose and on the impact that music has in our lives, but also how music activates the brain and plays an important role in our general brain development. What is extraordinary about music and the brain is that they are both mysteries and will remain so for a long time if not forever. Also, music is an intangible pleasure that we cannot afford losing as it is as important in our lives as eating although biologically speaking we will not die from music starvation... or will we?

Apparently, adults that learned a musical instrument when younger had on average 7 IQ points more than the adults that didn't. The inference that these individuals are more intelligent can be argued since the IQ rating is not the best representative of intelligence. Another interesting thing was that Alzheimer patients in there final stage could not remember a single person, object or event anymore, but music recognition was intact!

One of the highlights of the documentary is Dr. Daniel Levitin (McGill Researcher and Teacher) who did an experiment on the famous musician and song writer Sting. The latter was intrigued about Levitin's Research and decided to participate, which implied putting him in an fMRI (Functional Magnetic Resonance Imaging) scanner of the Montreal Neurological Institute and Hospital. Of the interesting findings of Levitin's experiment, there was the results showing that the caudate was strongly involved in creating new songs. Furthermore, Levitin found activation in the visual cortex and uncommon activation of the corpus callosum (being the major commissure in the brain connecting the two hemispheres) during creation of a song. Levitin stated that as pitch is mostly analysed in the right hemisphere, language is mostly in the left and further suggested that as artist grow more experienced and older, there activation while playing or inventing music is more distributed. Also, in another laboratory, it was found that the medial temporal lobe was strongly activated during improvisation. In yet another experiment, pregnant women or more so the foetuses were exposed to a specific song and, later when the child was born, it was found that those young children were more attentive and expressive when shown that specific song. It is important to mention that at 20 weeks, the offspring inside it's mother uterus can hear, but it does not see.

One of the findings that I really picked upon and that I will for sure mention in the second post on oxytocin is that this hormone is also highly secreted when singing in groups, which increased bonding.

I will end this post with this song A Thousand Years by Sting (cannot chose my favorite since there are so many amazing ones by Sting):


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For the official summary of the documentary, refer to:
http://www.ctv.ca/servlet/ArticleNews/show/CTVShows/20090115/musical_brain/20090119
You can also read the book of Daniel Levitin "This is Your Brain on Music".

Hormones & Psychology: Oxytocin (Part 1)

I find it crucial to discuss the endocrine system (hormonal system) and its role in behavior. I am quite disappointed that it is not a mandatory subject covered when doing a major in Psychology. It is well known that the nervous system works with the endocrine system to elicit different behaviors. Where some are found to be typical of either gender (influenced greatly by the hormone levels), other behaviors are triggered by experience and the processes of cognition in the brain. The endocrine system is also concerned with the never-ending nature-nurture debate as some hormone secretions depend on your genetic make-up (i.e. predisposition) and others depend on more direct environmental factors and past learning. [We know both genetic factors and environmental are responsible for behavior, therefore we should now focus on to what extent.] In that matter, as the nervous system elicits fast responses depending on the external stimuli, the endocrine system concerns itself with more bureaucratic (i.e. slow cascades of responses) with a few exceptions of course.

What is important to know about the connection between the nervous system and the endocrine system is that they communicate through the hypothalamus (a structure deeper in the brain that is not called a gland but that does secrete many hormones as well).When the hypothalamus secretes a hormone to release in the body or to trigger a cascade of other hormones in the body, this hormone has to pass by the gate called the pituitary gland in order to end up in the blood stream. Substances in the brain are highly controlled and separated from other substances in the rest of the body by the brain-blood barrier (a preventive measure in order to protect the brain from harmful substances). However, you might have guessed that drugs do end up fooling this barrier in order to elicit their effects on the brain. By now, I probably suffocated you with biology… In any case, I would like to discuss, now all that being said, about the hormone oxytocin and its role in behavior.

I haven’t yet done or found a good literature review on the subject of oxytocin. However, I would use a great book published recently on that matter (see its source below). Basically, oxytocin is made by the hypothalamus and secreted by the pituitary gland in the blood stream. Also, when I first learned about oxytocin, I was very intrigued that this hormone is one of the few exceptions that generate a positive feedback on its control center: the hypothalamus. In other words, upon secretion of oxytocin, high levels of this hormone will trigger even more release of that hormone. This being in contrast with most hormones that have a negative feedback on the brain, meaning that a high level of those hormones will trigger the brain to release less precursors (being hormones that will transform in another hormone) or other releasing hormones (hormones that trigger the release of another hormone). One of the major roles of oxytocin is of course during labor when you can understand the importance of a positive feedback as the contractions are getting stronger and more frequent. The second major role is the one of triggering the release of milk once the baby is born (mammary growth, milk production and release being controlled by the other hormones such as progesterone and prolactin). Here is a nice picture of the process of milk release by the mammary glands which is also called the oxytocin reflex or milk ejection reflex.

These bodily reactions are, as you noticed, automatic behaviors that any mother will go through and have no control over. However, some new research found that oxytocin has an important role in more complex behaviors. I would resume on this in a later post…
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BOOK SOURCE:

Neave, N. (2008). Hormones and Behaviour: A Psychological Approach. Cambridge, New York: Cambridge University Press.

I recommend you read Chapter 1 of this book since it is one of the best written summaries about the nervous system that I have read. It is concise, straightforward and covers the basic you need to know to get around in articles about the brain. Believe me I am quite annoyed with revisions and introductions on that matter and it is the first time I’ve read this part without being bored to death or pulling my hairs out.

Introduction: Brain Topography

Here's a simple brain map of the left side I have drawn for you to give you a sense of the main gyri (convolutions of the cortex of neurons on top of the brain) and sulci (crevices made in the cortex between convolutions). Basically, the brain is mostly made of glial cells that provide support and protection to the neurons that are responsible for communication within the body and picks up information from the environment via our senses. The cortex is a layer of those neurons, but also we find ganglions or areas dense in neurons deeper in the brain. In general, the deeper or further area from the cortex, the most basic the function of that area. As a contrast, the cortical areas carry further processing and associations between new information received by the senses, common knowledge and other experiences of our past. There has been and still is the debate on whether functions in the brain are localized (organized in modules) or distributed (the brain processing all information uniformly). Nowadays, that debate seems quite useless, because as we learn more about the brain from brain injuries and disorders, we see that there is to a certain extent some processes done in specific areas. However, we are far from phrenology (the study of bulges on the skull to determine one’s personality) introduced by Gall at the beginning of the 19th century[1].

I would like to finish this post by wishing you all very nice holidays and don't stop thinking. Here's a haiku (Japanese poem of 5-7-5 syllables) I have written a while ago inspired by the brain's cortex. Hope you enjoy :)

The brain's cortex:

paper fan folding our sky's

glittering knowledge.

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[1] Phrenology. (n.d.). The Oxford Companion to the Body. Retrieved December 24, 2008, from Answers.com Web site: http://www.answers.com/topic/phrenology