I recently wrote about why I quit watching football. I can no longer take pleasure in watching a sport where 1/3 of the players will end up with brain damage. I have been surprised since then at just how little I miss watching the games, and at how much more time I have on the weekend. Who knew!
Anyway, I found this TED Talk by Nancy Kanwisher. She uses fMRI scans to find and map activity in brain regions, and she shares what she and her colleagues have learned. It is a short talk and very interesting. As I watched it, I could not help thinking about how lucky most of us are not to hit our heads hard enough to damage our very-precious brains.
Our son, Jeff, is a biostatistician (at Columbia!) who has dealings with fMRIs. I’m his mother, so what those ‘dealings’ are is a mystery to me. So I asked him to try to explain to me what an fMRI really is:
Basically, an fMRI works by taking hundreds of full brain images in rapid succession — a couple of seconds apart for several minutes or longer. As the video says, these images should be slightly different from each other depending on what the subject’s brain is doing. Areas where neurons are firing need more oxygen, and this difference in oxygenation shows up in individual images. In the experiment, the subjects are shown pictures of faces or other objects; by the end of observation, there are many images under each condition and the researchers ask if, on average, on particular location in the brain has a different oxygenation level for faces than for other objects.
And then I asked what he, the biostatistician did with the data. He wrote:
The stats comes in when you try to decide which image locations are different under the two experiment conditions, after the fMRI data has been collected. Changes in blood oxygenation are typically small and there’s a lot of noise in the image, so it takes some effort to pick out areas that “light up”.
Hah! I almost understand a little bit of what my younger son does!
Last but not least, here’s a comic poking fun at TED, just for grins,…
I think I could come up with one or more NED talks :-). Really, aren’t the possibilities endless? Maybe we should start a trend, youtubing NED talks :-).