People can swiftly recognize small quantities (ranging up to four) but face difficulty with larger numbers. Groundbreaking studies have found specialized neural pathways for the processing of small and large numerical values. These neural activities are evidenced by brain waveforms. Credits: Christian Burkert/Volkswagen Foundation/University of Bonn
Researchers from the University of Tübingen and the University of Bonn have unearthed evidence supporting the existence of two distinct numerical cognition mechanisms.
When faced with a visual of two to four apples, individuals can quickly ascertain the count. However, when presented with five or more apples, the time needed for accurate recognition increases, and errors become more frequent. A recent study, undertaken collaboratively by the University of Tübingen, the University of Bonn, and University Hospital Bonn, substantiates that the neural processing of smaller quantities is unlike that of larger numbers. These findings have been published in the esteemed journal Nature Human Behaviour.
Consider a scenario where one is shown a photograph of a string quartet and asked to indicate the number of individuals present. The count of four is almost instinctively and confidently provided. However, if the next visual features a septet and only a fleeting moment is given for recognition, the answer becomes less certain, often estimated incorrectly as eight, when the actual count is seven.
Two separate cognitive approaches to numerical identification seem to be in play. Smaller numbers are generally recognized with rapidity and accuracy, a phenomenon termed “subitizing” in academic circles. This method becomes less effective when there are five or more elements, taking longer to answer and the responses becoming less accurate.
By using ultra-fine electrodes implanted in the temporal lobes of patients with epilepsy, researchers have been able to visualize neural activities in different brain regions. Credits: Christian Burkert/Volkswagen Foundation/University of Bonn
There has been speculation within the scientific community that two different neural processing systems are at play— one precise for smaller numbers and another approximative for larger numbers. “The alternative theory is that our brain estimates numbers in all instances, but the margin of error for smaller numbers is negligible and thus goes unnoticed,” elucidates Prof. Florian Mormann of the Department of Epileptology at University Hospital Bonn, who also conducts research at the University of Bonn.
The Specificity of Neurons for Smaller Numbers
The recent study lends credence to the theory that different cognitive pathways exist for small and large numbers. Previous work by the same groups showed that specific neurons are responsive to individual numbers. For example, certain neurons fire predominantly for the number two, others for four, and yet others for seven. “These neurons also react to minor numerical variations but with reduced intensity,” adds Prof. Andreas Nieder from the University of Tübingen, another principal investigator of the study.
Test participants were shown varying numbers of dots on a screen briefly, following which they were asked to indicate if the number was even or odd. For counts less than five, responses were usually accurate and instantaneous. For higher counts, both the reaction time and error rate increased proportionally.
Long-term Implications
This body of research has far-reaching implications, potentially aiding in the future understanding of conditions like dyscalculia, which involves difficulty in grasping numerical concepts.
Citations: “Distinct neuronal representation of small and large numbers in the human medial temporal lobe” by Esther F. Kutter, Gert Dehnen, Valeri Borger, Rainer Surges, Florian Mormann and Andreas Nieder, dated 2 October 2023, published in Nature Human Behaviour. DOI: 10.1038/s41562-023-01709-3
Participating Institutions and Funding Sources: The study was a collaborative effort involving the University of Tübingen, the University of Bonn, and University Hospital Bonn. Financial backing for the research came from the German Research Foundation (DFG), the German Federal Ministry for Education and Research (BMBF), and the iBehave Research Network in the State of North Rhine-Westphalia.
Table of Contents
Frequently Asked Questions (FAQs) about numerical cognition
What is the main focus of the study?
The primary focus of the study is to understand how the human brain processes numerical quantities. It explores the existence of specialized neural pathways for recognizing small and large numbers.
Who conducted the research?
The research was conducted collaboratively by the University of Tübingen, the University of Bonn, and University Hospital Bonn.
What methodologies were used in the study?
Ultra-fine electrodes were implanted in the temporal lobes of epilepsy patients to visualize neural activities. Participants were also shown varying numbers of dots on a screen briefly and were then asked to indicate if the number was even or odd.
What are the key findings of the study?
The study found that humans have two distinct mechanisms for processing numbers: one for small numbers (up to four) and another for larger numbers. This has been termed “subitizing” for smaller numbers.
What journal was the research published in?
The research was published in the esteemed scientific journal Nature Human Behaviour.
Are there any implications for conditions like dyscalculia?
Yes, the findings could potentially lead to a better understanding of conditions like dyscalculia, which is a developmental disorder affecting numerical understanding.
Who funded the research?
The research was funded by the German Research Foundation (DFG), the German Federal Ministry for Education and Research (BMBF), and the iBehave Research Network in the State of North Rhine-Westphalia.
What do the terms ‘subitizing’ and ‘numerical cognition’ mean?
Subitizing refers to the rapid and accurate recognition of small numbers of items without counting. Numerical cognition is the study of how organisms understand numbers and quantities.
Are there any alternative theories to the findings?
Yes, an alternative theory suggests that the brain estimates all numbers but has such a low margin of error for smaller numbers that it goes unnoticed.
What is the future scope of this research?
The research opens up new avenues for understanding how numbers are processed in the human brain and could inform the treatment and understanding of numerical disorders like dyscalculia.
More about numerical cognition
- Nature Human Behaviour Journal
- University of Tübingen Research
- University of Bonn Research
- University Hospital Bonn – Department of Epileptology
- German Research Foundation (DFG)
- German Federal Ministry for Education and Research (BMBF)
- iBehave Research Network
- Dyscalculia Information
- Numerical Cognition Overview
