Very young children are taught that two apples plus three apples make up a collection of five apples. In a recent study, scientists at the Universities of Tübingen and Bonn have shed some light on the neurology behind such calculations. Their results have been published in the journal Current Biology.
Addition and Subtraction:
Press reports on the results talk grandly about the discovery of “math neurons,” but the actual study was confined to two simply arithmetical functions, adding and subtracting.
Five women and four men allowed the experimenters to put electrodes in the temporal lobe of their brains to record the activity of nerve cells. With the electrodes in place, they were given arithmetical tasks. “We found that different neurons fired during additions than during subtractions,” said Prof. Florian Mormann from the Department of Epileptology at the University Hospital Bonn.
Strange New Worlds:
One interesting finding: the cells in question were not responding to the printed symbol “+” or “-“. The same neurons fired when the subjects read a text asking for the difference between 3 and 2, as fired when they saw the equation “3-2=?”. The neurons were reacting to a task, not to a particular sign. This may be an important step toward an understanding of the neurological level of accomplishing such a task.