Much of human behaviour is governed by common processes that unfold over varying timescales. New research, published in the journal PNAS, has found that human brain activity can stretch in time in a process called "temporal scaling".
Temporal scaling explains our ability to perceive, decide, and act flexibly in time. It happens when people try to produce or perceive precise temporal intervals (e.g. between two beats of a metronome or when we recognise the same music played faster or slower). It also happens when we make decisions – the brain activity for a slow decision looks like a stretched version of the brain activity for a fast decision.
Although temporal scaling has already been shown in monkeys using invasive brain recordings, the team of University of Oxford researchers found temporal scaling in humans using non-invasive scalp recordings (electroencephalography or EEG).
The practical implications for this research are exciting since it may provide a new way to measure brain activity relevant for understanding disordered timing. For example, patients with Parkinson's disease tend to underestimate the passage of time. The exact cause is unclear, but could relate to inaccurate temporal scaling.
Cameron Hassall, who led the research alongside senior investigator Laurence Hunt, said, "We're very encouraged about the implications of this research and our next step is to use our method to study music. Music is interesting because there is timing between notes, but also between groups of notes or measures. Our method could help us understand how the brain deals with both types of timing."
Read the paper. Hassall CD, Harley J, Kolling N, Hunt LT. Temporal scaling of human scalp-recorded potentials. Proc Natl Acad Sci U S A. 2022 Oct 25;119(43):e2214638119. doi: 10.1073/pnas.2214638119. Epub 2022 Oct 18. PMID: 36256817.
Image caption: Decisions occur over different timescales. For example, choosing a candy can be a fast decision or a slow decision. Decision-related brain activity appears to stretch or “scale” across time for slower decisions. The method used in this research separates stretched activity from non-stretched activity (e.g., the activity that occurs when you see the candies).