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




Monday, 26 October 2020
Behaviour as a control loop located outside the organism

With his famous Chinese Room Argument, philosopher John Searl raised an important question: can a computer understand Chinese (or French or English)? Probably not, if the results of some of today’s computer-translation programs are any indication. Unlike computers, we human beings can usually grasp the meaning of things fairly effortlessly, while a computer cannot. Many neuroscientists believe that to explain why, we must look more closely at the biological substrate of the brain, and in particular its long evolutionary history.

Indeed, the concept of embodied, situated cognition answers this question neatly: meaning can come only from the environment in the broad sense, which includes the body. The classic example is a mobile bacterium swimming through an aqueous medium in which there is a gradient of sucrose molecules. The bacterium moves through this medium randomly until sucrose receptors in its cell membrane sense these molecules. It then naturally begins to swim up this gradient, toward the source of the sucrose, to get more of it.

One important point to note here is that although the sucrose is a physical and chemical entity that exists in the bacterium’s environment, the status of sucrose as food for the bacterium does not follow automatically. That status is not intrinsic to the sucrose molecule but is instead a relational characteristic, connected to the metabolism of the bacterium that can assimilate this molecule and draw energy from it. The sucrose has value as food not in and of itself, but only in relation to an organism that can use it to maintain its homeostasis (its internal equilibrium and structural integrity) and stave off the second law of thermodynamics, that is, entropy.

Thus the particular positive or negative meanings that occur in the world are the result of the possible interactions between organisms and their environment. The meaning and value of things do not pre-exist in the physical world, but are instead manifested (or “enacted”) by organisms. That is why we can say that by definition, living is a process that creates meaning.

And that is why we can also redefine what a behaviour is, in light of all that. On the one hand, as we have just seen, there are countless feedback loops in our metabolism that enable our bodies to maintain their internal equilibrium, among other ways by digesting the food that they take in. But our behaviours also play a role in this homeostasis, by enabling our bodies to find this food in their environment. A behaviour can therefore be redefined as an extension of an organism’s physiological control mechanisms outside its own body. In other words, behaviour can be thought of as another control loop, but this time outside of the organism (rather than just an input-output process).

Uncategorized | Comments Closed


If you have a comment, please e-mail it to me, and I will post it here.