The human brain may have learned to comprehend the figure zero and apply it to our lives by making a primitive neural pathway more sophisticated. Better understanding this could help people who struggle to understand numbers after a stroke.
Zeros are used in many aspects of society, from astronomy and engineering to accounting and literature. To understand the figure鈥檚 origin, and at University College London used magnetoencephalography (MEG) to record the magnetic fields produced by 29 people鈥檚 brains while they completed two tasks.
In the first, they were asked to compare whether two consecutive patterns were made up of the same numbers of dots, from 0 to 5. In the second, they were shown 10 numbers, also from 0 to 5, each for 250 milliseconds. Half of these were orange and the rest blue. They were then asked to report which coloured numbers had the highest value.
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To compare the participants鈥� brain activity when they saw a 鈥�0鈥� with them seeing other numbers, the MEG data was fed into a machine learning algorithm.
杏吧原创s have long known that there are neurons in the brain that respond specifically to someone seeing a 鈥�1鈥� or a 鈥�2鈥� and so on until at least 鈥�9鈥�, says Barnett.
鈥淲e showed that the neural activity across different brain areas in response to 鈥�0鈥� was most similar to the activity underlying 鈥�1鈥�, compared to other numbers,鈥� he says. 鈥淲hat鈥檚 more, the neural activity for 鈥�0鈥� became less similar to brain patterns evoked by other numbers as these other numbers got larger, suggesting it has a place at the beginning of the neural number line 鈥� next to 鈥�1鈥�, and two less than 鈥�2鈥�, and so on.鈥�
The pair also looked for any similarities between the brain鈥檚 response to 鈥�0鈥� and a blank screen, finding that both activated the same brain activity pattern. This suggests that our understanding of the concept of zeros may have evolved from the perception of absences.
鈥淚f I鈥檓 an antelope on the savannah and I perform a quick visual scan to check if I can see any predators, the brain activity that leads me to decide 鈥榥o, I haven鈥檛 seen anything鈥� might be the precursor to the number zero in the brain,鈥� says Barnett. Humans and other animals seem to have the ability to understand absence, but people have built on this to utilise zeros, he says.
around 15 per cent were unable to accurately process numbers containing zeros in the following weeks.
鈥淥ur results may well contribute to a better understanding of this phenomenon and help inform potential treatments,鈥� says Barnett. 鈥淚t is also a good example of 鈥榗ortical recycling鈥�, where the brain co-opts existing circuits responsible for basic sensory functions in order to develop more complex cognitive capacities without having to create an entirely new set of neural circuits.鈥�
at Northeastern University in Boston, Massachusetts, says that despite the importance of zero in mathematics and various cultures, this study suggests it originates from the ability to notice absences, which we probably share with other animals.
bioRxiv
