How Much Control Do We Have Over Our Brains?

There is a significant trend in neuroscience, and maybe even more so among the commentators who use that science to justify their political or social beliefs, of denying that we are really responsible for our own behavior. The usual argument goes like this: when a person does X, their brain scans light up in a certain way. People with brain damage to that area don't do X, or do it differently. Therefore we don't really have control of ourselves, our decisions or beliefs are just a function of our anatomy. I have written critically about these Just-So Science Stories here. Other writers (ok, better writers), in a political context, have pointed out that some liberal social scientists have started using this same approach to define conservatism as a disease.


However, just because science can be manipulated to support certain dubious conclusions doesn't mean there isn't a lot of interesting work being done in understanding how the brain works. And one such finding has to do with how a parasite in our brains might be responsible for our positive reactions to the scents of certain wines and perfumes. As writer Patrick House puts it:

Why is it that the elite French perfumers (known as “noses”) and sommeliers (“upturned noses”) of the world spend so much of their time inhaling cat effluvia from expensive glass bottles? A guess: It may have to do with a mind-control parasite called Toxoplasma gondii. The tiny protozoan may be getting into our brains and tricking us into liking cats—not to mention certain perfumes and wines.

In a recent study, Czech scientists gave men and women towels scented with the urine of various animals—horses, lions, hyenas, cats, dogs—which they rated for “pleasantness.” Turns out, men who tested positive for Toxo found the smell of cat urine more pleasant than men without Toxo. For Toxo researchers like me, this was a shock but not entirely surprising. Why? Toxo does approximately the same thing to rats.

You'll have to read the article to get the full theory of why Toxo does what it does, but the implications are staggering: a single-celled organism might be altering way our brain processes information from our senses. Think of it: could we find a bacteria that lowers the speed at which our neurons fire, influencing how fast we remember or respond to stimuli? Could we find a parasite that alters our hearing our sight?

Or think of the commercial issues. Some perfume and wine companies would presumably do better if more people were infected by Toxo. Maybe Chanel will start working with animal adoption organizations to try to get cats into more homes, increasing their likely customer base.

If we begin to discover that some significant portion of the way we perceive the world is influenced by outside organisms, will we attempt to purge them all to standardize the way the human mind works? Will we search for those with favorable impacts and try to infect everyone with them? Could this be the next frontier in pharmaceutical development? Or is this a one-off, and our mental machinery is basically unaltered by microscopic invaders? I guess we just have to wait and see.