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




Tuesday, 9 January 2018
The Baseball Batter’s Predictive Brain

For some years now, cognitive scientists have increasingly come to regard the human brain as a machine for making predictions. In other words, these scientists think that our brains spend most of their time trying to figure out what is going to happen next so that they can take action accordingly. The great adaptive value of such a process is immediately obvious.

The theoretical framework underlying this view of things is extensive and fairly new, although it has roots in 18th-century philosophy. Some authors even describe it as a paradigm shift, the same term that has been applied in turn to the cognitivist, connectionist and embodied dynamic approaches over the past half-century. But these models involve Bayesian probabilities and cannot be readily expressed in simpler terms, much to my own dismay (I’d like to write about them more often in this blog, but don’t always manage to).

In any case, recently I came across a video that’s scarcely two minutes long and at first glance has nothing to do with this new paradigm but actually presents its fundamentals in a highly concrete way by addressing the following question: how do professional baseball players manage to hit a fastball? The adjective “professional” is important here, because it’s what make this seemingly simple question so complicated. When a professional pitcher throws a fastball, it is travelling about 95 miles (150 km) per hour at the time of release and has only 55 feet (slightly less than 17 m) to go before reaching the catcher’s mitt. This means that the ball covers this distance in just 400 milliseconds.

As the video explains, the batter’s visual system needs nearly 100 milliseconds to process any stimulus. If the batter decides to swing, it will then take 25 milliseconds for the motor commands from the batter’s brain to reach the batter’s muscles, and an average of 150 milliseconds for the batter to swing the bat. Subtract those three numbers from 400, and that leaves the batter only 125 milliseconds to decide whether to swing at the pitch. That’s an extremely short reaction time—as the video points out, it takes you 300 to 400 milliseconds just to blink your eyes. So how, then, do professional baseball players still manage to hit fair balls so often?

The answer can be summed up in a single word: anticipation. As the video explains, this anticipation takes at least two forms. First, the batter can try to get a head start by beginning to swing when there is still very little information about the path that the ball is going to travel. But the batter can’t start to swing too early, because after about 50 milliseconds, the bat’s inertia will make it impossible for the batter to check (stop) the swing.

The other form of anticipation at work here is the one that involves the “predictive brain”: our spontaneous ability to predict what is likely to happen on the basis of our past interactions with the world, which are encoded in the brain as a priori models. In the present case, the brain can anticipate the position of a moving target from cues inside an extremely short time window. This principle is well illustrated in the video by the “flash drag” effect, in which the direction in which the background is moving causes the viewer to perceive the positions of the red and blue dots incorrectly (offset in the direction in which the background is moving rather than in their true position).

And the same phenomenon is at work when a batter successfully uses the bat to make contact with the the ball. The batter’s brain starts to anticipate the ball’s trajectory before it has even left the pitcher’s hand, simply from the dynamics of the pitcher’s movement. Then the ball’s trajectory over the first few metres after the pitcher releases it provides further information that the batter’s brain can use to predict the ultimate position of this moving object. The bottom line: with a lot of training, a professional baseball player’s brain can successfully perform a task that would appear to be physically impossible!

Body Movement and the Brain | No comments


Tuesday, 19 December 2017
Blog posts in French in December 2017 – Part II (English posts return in January 2018)

As I wrote two weeks ago, Al Daigen, who has translated all the of content for The Brain from Top to Bottom from French into English and who continues to translate selected posts from this website’s blog, will be taking a well earned vacation in December 2017. Since my English is not up to his high standards, I’m not going to try to replace him. But to make sure you don’t have to go too long without hearing from me, I want to let those of you who can read French know about 8 posts based on the lectures that I gave this fall at the “Université du troisième âge (UTA)” and that I think you will enjoy. (more…)

From the Simple to the Complex | No comments


Wednesday, 6 December 2017
Blog posts in French in December 2017 (English posts return in January 2018)

Al Daigen, who has translated all the of content for The Brain from Top to Bottom from French into English and who continues to translate selected posts from this website’s blog, will be taking a well earned vacation in December 2017. Since my English is not up to his high standards, I’m not going to try to replace him. But to make sure you don’t have to go too long without hearing from me, I want to let those of you who can read French know about 14 posts based on 14 lectures on embodied cognition that I gave last fall at the Université du Québec à Montréal and that I think you will enjoy. Unfortunately, the rest of you will either have to wait until Al’s translations of recent posts begin appearing here again on January 8, 2018, or try your luck with Google Translate, which has improved a fair bit in recent years, thanks to “deep learning” technology.

Body Movement and the Brain | No comments


Tuesday, 21 November 2017
Conceptual evolution in some explanations in neuroscience

This website and this blog have been around long enough now (over 15 years and nearly 7 years, respectively) to have witnessed the ongoing evolution and refinement of certain concepts in the neurosciences. We all know that science evolves, but it can be interesting to see how. That’s what I’d like to show today, using an example of conceptual evolution. This example relates to the amygdalae—the two almond-shaped groups of neuronal nuclei on either side of the brain that were associated with human fear reactions very early in the history of neuroscience. Indeed, studies such as those by Joseph LeDoux have shown that when a threatening stimulus is presented to rats or humans, the neurons in each amygdala in their brains become highly active.

But as brain-imaging studies became more common, they showed that the activity in someone’s amygdala could also increase in other situations as well (for example, when that person was extremely hungry or saw a loved one suffering). (more…)

Emotions and the Brain | No comments


Thursday, 26 October 2017
The Brain, The Body and the Environment: We Need All Three To Make Thinking Possible

The third and final session of my course at UPop Montréal started by asking whether our brains really process our most abstract concepts in the way proposed by cognitivist theory: that is, as arbitrary symbols that have nothing to do with the sensory modalities by which these “inputs” are entered. But as early as the 1960s, experiments with the mental rotation of objects seemed to suggest that, on the contrary, when we perform “high-level” mental manipulations of this kind, we employ the sensory regions of our brain to do so. (more…)

Body Movement and the Brain | No comments