Researchers at Stanford University School of Medicine claim to have identified a brain region which is uniquely responsible for mathematical thinking. Say hello to your intraparietal sulcus, or IPS: it’s what provides your numeracy (or lack of it). The IPS is activated when (and only when) you think about numbers, including imprecise quantitative terms such as “more than”.
One of the interesting aspects of this study is the unusual way the researchers obtained their data. Brain studies are usually carried out on patients lying immobile inside MRI scanners, which are huge, clunky, and noisy machines with giant magnets. Or they are carried out by electro-encephalography (EEG), in which multiple electrodes are placed on the scalp. These techniques do not allow the subjects to move around freely and engage in normal day-to-day activities, and EEG is also imprecise.
The Stanford study was carried out on a group of volunteers who were being evaluated for possible surgical treatment of recurring, drug-resistant epileptic seizures. Portions of their skulls were temporarily removed, and packets of electrodes were placed against the exposed brain surface. They remained hooked up to monitoring apparatus for up to a week, during which time they could chat to family and friends, drink tea, watch videos, and so on.
The electrodes acted like wiretaps, eavesdropping on several hundred thousand nerve cells and reporting back to a computer. The participants’ actions were also monitored by video cameras throughout the process, so that their external behaviour could be correlated with the behaviour of their neurons.
The researchers got a bit carried away when reporting their findings, and suggested this could lead to the technology of mind-reading. But there is a sizeable gap between detecting the presence of numerical thinking, and knowing the specific content of a thought. Also, as they themselves pointed out, this procedure cannot be used surreptitiously.