Numbers and the Brain: Neural Implications of Reading Numbers as Arabic Numerals vs. Words

Reading Arabic numerals vs. verbal numerals changes neural processing and affects speed and accuracy in understanding the meaning of numbers.

Editing is not a completely standardized field, as each style guide offers its own recommendations on various topics. One such topic is the issue of how to deal with numbers in writing. Some style guides prescribe the use of Arabic numerals (e.g., 1,2,3), some prescribe spelled-out verbal numerals (e.g., one, two, three), and others prescribe a mixture of these two formats. Understanding how the brain processes different formats of numbers may help editors determine how to portray numbers.

THE RESEARCH

In “Distinct Neural Mechanisms for Reading Arabic vs. Verbal Numbers: An ERP Study,” researchers  Alice Mado Proverbio, Marco Bianco, and Francesco De Benedetto from the Milan Center for Neuroscience address the neural processing of numbers. In this study, each of the 16 participants saw 720 numbers presented in pairs of either two Arabic numerals or two verbal (i.e., spelled out words) numerals. Participants determined whether the numbers in each pair were identical to each other (e.g., 27 and 27 are the same but 36 and 98 are not) while electroencephalogram (EEG) data was collected. The researchers tracked and analyzed the participants’ response times and accuracy.

The researchers found that participants had significantly higher accuracy and significantly faster response times with Arabic numerals. Additionally, EEG data revealed that initial brain activity for Arabic numerals occurred in both brain hemispheres (suggesting a more efficient pathway to processing meaning), while activity for verbal numerals was initially concentrated in the left hemisphere. Together, these results “[indicate] that the Arabic format type was the most advantageous, as it promoted a much faster and reliable access to numeric meaning (semantic content)” (Proverbio et al. 2018, 4485). 

Furthermore, the data suggests that understanding verbal numerals is a more demanding process than understanding Arabic numerals: Heightened activity in areas of the brain related to comprehension was seen later when participants processed verbal numerals than when they processed Arabic numerals, and a comparison of EEG deflections at these points indicates that the brain used more resources to interpret verbal numerals. These differences imply that fully processing verbal numerals requires additional steps and energy.

THE IMPLICATIONS

Based on this study, neural processing appears to differ between Arabic numerals and verbal numerals. The data suggests that people process Arabic numerals faster and more accurately. This knowledge is relevant to the field of editing: As editing professionals construct and revise style guides, they can consider how formatting numbers affects comprehension. While style guides influence which number system to use, editors could consider updating in-house style guidance to recommend using Arabic numerals to ensure faster and better understanding for readers. As the editing industry makes changes in line with research from other disciplines such as neuroscience, written materials will become more optimized for efficiency and comprehension.

To learn more about the differences in how the brain processes Arabic and verbal numerals, read the full article:

Proverbio, Alice Mado, Marco Bianco, and Francesco Benedetto. 2020. “Distinct Neural Mechanisms for Reading Arabic vs. Verbal Numbers: An ERP Study.” The European Journal of Neuroscience 52 (11): 4480–9. https://doi.org/10.1111/ejn.13938.

—Abigail Christensen, Editing Research

FEATURE IMAGE BY BEASTERNCHEN

Find more research

Read Peter Walla and Philipp Klimovic’s (2025) article to find out more about the way presentation affects how numbers are processed in the brain: “Time Course of Brain Activity Changes Related to Number Study.” Applied Sciences 15 (2). https://doi.org/10.3390/app15020530.

Take a look at Manuel Carreiras, Philip J. Monahan, Mikel Lizarazu, Jon Andoni Duñabeitia, and Nicola Molinaro’s (2015) paper to get a better understanding of the differences between verbal and numerical processing in the brain: “Numbers Are Not Like Words: Different Pathways for Literacy and Numeracy.” NeuroImage 118: 79–89. https://doi.org/10.1016/j.neuroimage.2015.06.021.

Take a look at Jie Liu, Han Zhang, Chuansheng Chen, Hui Chen, Jiaxin Cui, and Xinlin Zhou’s (2017) study to discover how the brain processes arithmetic principles: “The Neural Circuits for Arithmetic Principles.” NeuroImage 147: 432–46. https://doi.org/10.1016/j.neuroimage.2016.12.035.