How do we perceive time? One typical way of understanding this is called the “pacemaker model.” The model is based on the idea that there is a ticking pacemaker and accumulator in our mind and that when a certain number of ticks have accumulated in the pacemaker, we feel that a certain amount of time has passed.
Fun times seem to pass quickly because the pacemaker ticks faster than usual, making time accumulate in a shorter period than it does. This is only a hypothetical conceptual model; we do not have a pacemaker in our minds. However, there is a trend in research to try to understand human time perception by assuming the existence of such a pacemaker.
fMRI that measures brain structure and function. The brain is scanned with this instrument to study the brain’s perception of time and other aspects of the brain. Image credit: University of Tokyo
There are brain waves with different frequencies, such as alpha and beta waves, that may be related to what accelerates and decelerates the pacemaker. Brain cells are activated while brain waves of various frequencies are synchronized. The timing of the synchronized activity is likely associated with the speed of the pacemaker.
Dopamine levels increase with enjoyment
While our brains have visual and auditory cortices that process sounds and images, no regions dedicated solely to temporal information processing have been found in our brains. From another perspective, all brain regions can influence the pacemaker’s speed.
In the brain, the subcortical areas control breathing and regulate body temperature while the cerebral cortex is responsible for higher cognitive functions such as information processing and thinking. Both cortices are also involved in temporal information processing.
Among these areas, the basal ganglia are the most influential. They are involved in the release of the neurotransmitter called dopamine. If we lack dopamine, we cannot perceive time properly. The amount of dopamine increases when we feel happy.
Image of the brain scanned by fMRI. Image credit: University of Tokyo
Many things are still not fully understood about how humans perceive time, which is what I am researching. My laboratory conducts psychological experiments and functional magnetic resonance imaging (fMRI) for the analysis of brain activity in order to understand the mechanism of time perception, ranging from a few seconds to a few minutes at the longest.
For example, when electrodes for electroencephalography are attached to the back of the head for measurement, alpha wave components at around 8 Hz to 12 Hz are often observed. We apply electrical current externally to the electrodes to accelerate or decelerate the synchronized neural activity forcibly. This allows us to measure how time perception is affected.
Basic research is not about predicting “what will be useful to the world.” Rather, it is about finding the answers to the mysteries that lie before us through experiments. That is the fun and joy of the process.
Author: Yuko Yotsumoto, Professor, Graduate School of Arts and Sciences
Source: Tokyo University of Science