After providing all the funding for The Brain from Top to Bottom for over 10 years, the CIHR Institute of Neurosciences, Mental Health and Addiction informed us that because of budget cuts, they were going to be forced to stop sponsoring us as of March 31st, 2013.

We have approached a number of organizations, all of which have recognized the value of our work. But we have not managed to find the funding we need. We must therefore ask our readers for donations so that we can continue updating and adding new content to The Brain from Top to Bottom web site and blog.

Please, rest assured that we are doing our utmost to continue our mission of providing the general public with the best possible information about the brain and neuroscience in the original spirit of the Internet: the desire to share information free of charge and with no adverstising.

Whether your support is moral, financial, or both, thank you from the bottom of our hearts!

Bruno Dubuc, Patrick Robert, Denis Paquet, and Al Daigen

Thursday, 28 May 2020
Dancing (like playing music) alters your brain if you do it a lot

The various brain-imaging techniques that have been available for some decades now have made it possible to observe the structural anatomical changes that occur in the brains of people who engage regularly in a given a activity, such as dancing or playing music. Today I want to talk about research on these changes that has been conducted recently by Falisha Karpati of McGill University in Montreal. In her 2017 study entitled “Dance and music share gray matter structural correlates”, she compared the brains of professional dancers with those of professional musicians, on which more research had previously been done. In her 2018 study, “Structural Covariance Analysis Reveals Differences Between Dancers and Untrained Controls, she compared the brains of professional dancers with those of control subjects who had no dance training. In these two studies, Karpati found that dancing or playing music for eight hours every day does indeed make one’s brain different from those of people who do neither.

But different in what way? The changes that Karpati observed consisted in thickening of certain areas of the cerebral cortex, a layer of neurons that is normally only 2 to 3 millimetres thick. And (although Karpati’s studies don’t mention this fact directly), many other studies have shown that one of the aspects of the neuronal plasticity responsible for this thickening appears to be the development of new dendrites in cortical neurons that are activated frequently.

As Karpati explains in a short video interview, among all the parts of the cerebral cortex that may be activated when someone dances or plays music, there are two particular areas whose volume she found to be appreciably greater in dancers and musicians than in her control subjects. The first of these areas was the right superior temporal gyrus (see illustration above), which is involved in many functions, including integration of auditory, visual, somatosensory and other sensory inputs as well as sensory and motor integration, all of which are, of course, important aspects of dance and music.

The other area was the left dorsolateral prefrontal cortex, which has a special relationship to dancing. This part of the brain becomes active when someone is observing body movements with the goal of reproducing them (and may involve the activity of mirror neurons). It also becomes active when someone engages in motor mental imaging (either imagining themselves performing a movement or trying to predict what movement another person is going to make).

So, as the reporter asks Karpati in the interview, did dancing a lot really cause these areas of the dancers’ cortexes to thicken, or did these individuals become dancers because they were born with these parts of their cortexes more developed than other people’s, which made it easier for them to achieve a high level of dance performance?

Karpati thinks that the answer may be: a bit of both. She did not study the same individuals before and after they became professional dancers, so she has no way of proving either possibility. But she does note that other longitudinal studies have shown that practicing dance for an extended time does increase the volume of these brain structures. Other studies have shown that subjects who were not dancers but in whom these brain structures were larger did in fact learn more quickly how to dance. But this does not tell us whether these brain structures had been larger from birth. They may also have grown larger at least partly as the result of other motor learning that these individuals did in which these structures were activated.

As Karpati says toward the end of her interview, we now have a good idea of the changes that the brain undergoes after repeated dance practice. We also now know the activation patterns in the brains of people watching other people dance (and even how these patterns differ according to whether the people watching know how to dance the particular dance they’re watching). The next step will be to record the overall brain activity of people while they are actually dancing. That would scarcely be practical with the bulky equipment now used to do magnetic resonance imaging. But new technologies such as near-infrared spectroscopy use equipment so light that it can be incorporated into a headband that someone can wear while dancing. Thus we might well soon be able to watch the cortexes of dancers at work in real time (the cortexes, mind you, and not the entire brain, because one of the limitations of this technology is that it cannot capture images any deeper into the brain).

Uncategorized | Comments Closed

Tuesday, 19 May 2020
Neural correlates of mathematical beauty

This week I’d like to tell you about a study published in 2014, entitled “The experience of mathematical beauty and its neural correlates”.

We know that mathematicians have long talked about experiencing genuine aesthetic pleasure at the sight of certain mathematical formulas. We also know from several brain-imaging studies that activation of field A1 of the medial orbito-frontal cortex (mOFC) is one of the most common neuronal correlates of the more conventional, sense-based experience of beauty (for example, in someone’s face, or in a landscape, or in a piece of music). Hence the authors of this study (neuroscientist Semir Zeki and his colleagues) decided to investigate whether the aesthetic pleasure that mathematicians derive from such a seemingly abstract source as a mathematical formula activates this same area in their brains. And the answer seems to be yes. … (more…)

Pleasure and Pain | No comments

Tuesday, 21 April 2020
The rubber-hand illusion

The sense that you have a body and can distinguish what’s part of it from what’s not is with you all the time. It’s so familiar that it’s hard to imagine not having it. Yet several experiments, such as the rubber-hand-illusion experiment described in this post, show that this sense is actually a complex construct that your brain assembles from the myriad pieces of sensory information that it receives constantly. (more…)

The Emergence of Consciousness | No comments

Wednesday, 8 April 2020
Spectacular advances in two-photon microscopy and two-photon calcium imaging

What if I told you that scientists had just succeeded in recording the simultaneous activity of 12 000 neurons in the cortex of a mouse as it moved freely around its cage, and that they had done so at the cellular level, down to a frequency of 17 Hertz? Would you say something like, “So what?” or “Who cares?” or “Why don’t you tell me in language I can understand?” In this post, I’m going to try to meet that last challenge. (more…)

From the Simple to the Complex | No comments

Tuesday, 17 March 2020
A Chair Doesn’t Have To Be Electric To Be Dangerous

Moving is good for your brain. We all know this instinctively, because of the way we just feel better after walking, dancing, playing soccer or engaging in other physical activity. But too often, we forget, because we have too much work to do, too many e-mails to answer, too many TV series to stream and so on. As a result, all too many of us end up spend all too many hours sitting every day. Scientists who study this issue use the term “sedentariness” to describe this pattern in which people remain seated and expend very little energy for long periods. And the scientists’ studies have shown that there is a meaningful distinction between how sedentary someone is and how much physical activity they engage in every day or week. (more…)

Body Movement and the Brain | No comments