Wiederhold, B. | Search bioRxiv

bioRxiv2025

Mental calculation: the fastest high-level cognitive ability of human beings?

While our senses transmit information at rates exceeding 106 bit/s, high-level cognitive processing is thought to be much slower, on the order of 10 bit/s regardless of the task1. It is unclear, though, whether this limit holds when the human mind is challenged. To test how fast one can process abstract information, we analyzed mental calculations, using data from international competitions and record-setting attempts. We discovered scaling laws relating task complexity and completion speed. High information rates were sustained for minutes, peaking at above 215 bit/s for the shortest calculations, split into 125 bit/s for conscious perception and 90 bit/s for algorithmic execution. These rates are well in excess of previous estimates for high-level mental abilities.

neuroscience↗

bioRxiv2025

The speed of information processing at memory competitions: limited by reading in short tasks and declining as a power law for longer times

As anyone who has tried to memorize a one-hundred-digit number can attest, acquisition of numerical information typically proceeds at less than one bit/s. If human memory operated at this speed in general, even a simple conversation would not be possible. Indeed, through techniques such as the memory palace, which translate numerical information into more natural contexts, memory athletes manage considerably higher rates. This suggests that memory, in its intended environment and under training, performs at substantial speed, which can be quantified in memory competitions. Analyzing the data reveals three phenomena. First, in short-duration tasks up to 42 bit/s have been achieved. Remarkably, competitors spend most of the time on reading, indicating that they form mental associations even more rapidly. Second, record performances show a remarkable concordance across time scales: the processing speed depends on memorization time as a power law. Third, despite dramatic improvements in scores and mnemonic strategies over the last decades, the differences in information rates across memorization tasks remain remarkably consistent.

neuroscience↗