Tübingen neuroscientists discover brain processes which lead to the concept of “zero” on the number line
Zero is a magic number. It stands for emptiness, for nothing – and yet it is considered one of the greatest cultural achievements of humankind, making the breakthrough for science and mathematics. It took a long stretch of human history for zero to be recognized and appreciated.
Even children understand that zero itself is a number only after they have learned to count other numbers. It is not easy for human beings to comprehend an empty set as an abstract numerical value. University of Tübingen neuroscience researchers headed by Professor Andreas Nieder now have some answers as to how and where brain cells depict a zero amount as a part of the number line.
The researchers trained two rhesus monkeys to assess the number of dots on a computer screen from zero to four. In the test, the monkeys judged “no dots” as the number closest to one, thereby giving it quantitative significance at the start of the number line.
While this was happening, the researchers measured the activity in two parts of the monkeys’ brains, the parietal lobe and the frontal lobe, which is the next place neural signals are sent. The researchers had shown in the past that these two regions play a key role in the processing of quantities. “A comparison of the two brain regions showed an initial amazing transformation in the way empty sets are portrayed by neurons,” says Andreas Nieder.
Nerve cells in the parietal lobe registered the lack of countable dots as a missing visual stimulus, without quantitative significance and therefore fundamentally different from numbers. But at the next level at which processing takes place, the frontal lobe, the neurons treated the absence of elements as an empty set among other countable sets, with the greatest similarity to the number one. “Not until it gets to the frontal lobe does the empty set become abstracted as a value on the number line, analogously with the behavior of the animals,” says Nieder.
The new findings provide information on how and just where the brain actively translates an absence of countable stimuli into a numerical category. “For a brain which has evolved to process sensory stimuli, conceiving of empty sets is an extraordinary achievement,” Nieder says.
“This is the first sign of the ability to formulate concepts independently of experience and beyond what is perceived, just as required for a complex number theory.” That the nerves in the prefrontal cortex are capable of making that step confirms the tremendous significance of this area of the brain for abstract thought – which is frequently disrupted in neuropsychiatric disorders.
Araceli Ramirez-Cardenas, Maria Moskaleva & Andreas Nieder: Neuronal representation of numerosity zero in the primate parieto-frontal number network. Current Biology.
Online: 21 April 2016, DOI: http://dx.doi.org/10.1016/j.cub.2016.03.052
Professor Andreas Nieder
University of Tübingen
Institute of Neurobiology – Animal Physiology
Phone: + 49 7071 29-75347
Dr. Karl Guido Rijkhoek | idw - Informationsdienst Wissenschaft
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction