When performing calculations, some neurons are energetic when including, others when subtracting.
The mind has neurons that fireplace particularly throughout sure mathematical operations. This is proven by a current examine performed by the Universities of Tübingen and Bonn. The findings point out that a few of the neurons detected are energetic solely throughout additions, whereas others are energetic throughout subtractions. They don’t care whether or not the calculation instruction is written down as a phrase or an emblem. The outcomes have now been printed within the journal Current Biology.
Most elementary faculty kids most likely already know that three apples plus two apples add as much as 5 apples. However, what occurs within the mind throughout such calculations continues to be largely unknown. The present examine by the Universities of Bonn and Tübingen now sheds gentle on this concern.
Some neurons within the mind grow to be energetic particularly as well as duties, others in subtraction. Credit: Christian Burkert/Volkswagen-Stiftung/University of Bonn
The researchers benefited from a particular function of the Department of Epileptology on the University Hospital Bonn. It focuses on surgical procedures on the brains of individuals with epilepsy. In some sufferers, seizures all the time originate from the identical space of the mind. In order to exactly localize this faulty space, the docs implant a number of electrodes into the sufferers. The probes can be utilized to exactly decide the origin of the spasm. In addition, the exercise of particular person neurons could be measured by way of the wiring.
Some neurons hearth solely when summing up
Five girls and 4 males participated within the present examine. They had electrodes implanted within the so-called temporal lobe of the mind to file the exercise of nerve cells. Meanwhile, the contributors needed to carry out easy arithmetic duties. “We found that different neurons fired during additions than during subtractions,” explains Prof. Florian Mormann from the Department of Epileptology on the University Hospital Bonn.
It was not the case that some neurons responded solely to a “+” signal and others solely to a “-” signal: “Even when we replaced the mathematical symbols with words, the effect remained the same,” explains Esther Kutter, who’s doing her doctorate in Prof. Mormann’s analysis group. “For example, when subjects were asked to calculate ‘5 and 3’, their addition neurons sprang back into action; whereas for ‘7 less 4,’ their subtraction neurons did.”
For the examine, tiny electrodes have been implanted within the brains of 5 girls and 4 males to measure the exercise of particular person neurons. Credit: Christian Burkert/Volkswagen-Stiftung/University of Bonn
This exhibits that the cells found really encode a mathematical instruction for motion. The mind exercise thus confirmed with nice accuracy what kind of tasks the test subjects were currently calculating: The researchers fed the cells’ activity patterns into a self-learning computer program. At the same time, they told the software whether the subjects were currently calculating a sum or a difference. When the algorithm was confronted with new activity data after this training phase, it was able to accurately identify during which computational operation it had been recorded.
Prof. Andreas Nieder from the University of Tübingen supervised the study together with Prof. Mormann. “We know from experiments with monkeys that neurons specific to certain computational rules also exist in their brains,” he says. “In humans, however, there is hardly any data in this regard.” During their analysis, the two working groups came across an interesting phenomenon: One of the brain regions studied was the so-called parahippocampal cortex. There, too, the researchers found nerve cells that fired specifically during addition or subtraction. However, when summing up, different addition neurons became alternately active during one and the same arithmetic task. Figuratively speaking, it is as if the plus key on the calculator were constantly changing its location. It was the same with subtraction. Researchers also refer to this as “dynamic coding.”
“This study marks an important step towards a better understanding of one of our most important symbolic abilities, namely calculating with numbers,” stresses Mormann. The two teams from Bonn and Tübingen now want to investigate exactly what role the nerve cells found play in this.
Reference: “Neuronal codes for arithmetic rule processing in the human brain” by Esther F. Kutter, Jan Boström, Christian E. Elger, Andreas Nieder and Florian Mormann, 14 February 2022, Current Biology.
DOI: 10.1016/j.cub.2022.01.054
The study was funded by the German Research Foundation (DFG) and the Volkswagen Foundation.
