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
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences