Anyone who has sat through a boring meeting knows that five minutes can seem like an hour. Yet, time can seem to fly by when you are working hard on a project for a deadline. These two experiences are both related to psychological time measurements, which researchers have studied since the beginning of experimental psychology. Over time, scientists have shown that internal time-keeping is far from absolute.

Timing, the Brain, and Fighter Pilots

Since the early 1800s, psychologists have been testing how humans interpret time. Experiments dealing with duration, or length, attempt to explain the old adage, “Time flies when you’re having fun.” In these duration experiments, scientists ask participants to estimate the amount of time they spend completing an activity. The scientists change different aspects of the activity, such as difficulty and length, and look for correspondence between variable aspects and the time estimates of the participants.

Many modern experiments rely on the theory that the cerebral cortex is the part of the brain responsible for keeping track of time. In these experiments, the difficulty level of the activities is changed to require greater use of the cerebral cortex. Hypothetically, as the difficulty increases, less brain power can be used to keep track of time, and time estimates should be small.

In fact, research has shown that people with damaged cerebral cortexes have difficulty keeping track of time.

“There is some evidence that patients with lesions of the cerebral cortex can have deficits in timing, which often express themselves as language deficits,” says David Eagleman, Professor of Neuroscience at the University of Texas at Austin. “In children, cortical timing problems can actually lead to learning disabilities.”

On the other hand, some people are better able to keep track of time, which may correspond to enhanced use of the cerebral cortex.

“Some related studies on the ability to keep track of many moving objects at the same time show that, for example, NBA basketball players and Israeli jet fighter pilots are much better than normal people,” said Eagelman. Whether the enhanced time-keeping ability is genetic or learned is unknown.

Prospective vs. Retrospective

Don’t think about giraffes.

If you are now thinking about giraffes, then you are illustrating one of the difficulties of the cerebral cortex-based experiments. If participants are told ahead of time that they are going to make time estimates, then these participants may think about time, and thus use more of the cerebral cortex for time-keeping than they otherwise would. To deal with this problem, psychologists have differentiated between two kinds of time estimates, prospective and retrospective.

In prospective time estimates, participants know ahead of time that they are going to be asked to estimate time.

In retrospective time estimates, participants do not know that they will be asked to estimate time at the end of the activity.

The Results

In 1990, William Friedman published a review of 70 time experiments, including a list of phenomena that occur during duration time estimates. The first of the Friedman phenomena is that people underestimate time while completing attention-demanding tasks. Most experimental research shows that this phenomenon occurs because people’s attention is diverted from time-keeping when they are engaged in challenging activities. While time may fly when you are having fun, Friedman also points out that time slows down during periods of high expectation, nervousness, fear, or anticipation.

Friedman also states that time goes by quicker as you age. Researchers have shown that the relationship between age and time perception is logarithmic, meaning that people measure time relative to their age.

Even memory can affect how you perceive time. Friedman states that a time period seems longer if remembered in detail, and shorter if remembered only in outline. Similarly, many events during a time period lead to overestimates of duration. Friedman explains these phenomena with people’s tendency to assume that it takes longer for many events to occur than for a few to occur.

Friedman acknowledged that some of these phenomena have more experimental support than others.

In a recent study, University of Alberta scientists Anthony Chaston and Alan Kingstone showed that time flies for people whose attention is actively engaged, supporting the first Friedman phenomena.

In the Chaston-Kingstone experiment, groups of participants searched through various images looking for certain objects, referred to as a “Where’s Waldo” type activity. These searches are called “conjunction searches” because they utilize the cerebral cortex.

The two researchers found that even in prospective time measurements, people increasingly underestimate time as the difficulty of the activity increases. In other words, time flies when you’re busy.

Chaston and Kingstone’s findings are important because of society’s focus on time. As Richard A. Block and Dan Zakay explain, “A person must encode temporal properties of important events…For example, driving a car requires a person to estimate durations in order to engage in appropriate actions at a correct time.”

Also importantly, Chaston and Kingstone’s results show that even when someone knows ahead of time they are going to estimate duration, time still flies while completing more difficult tasks.

In a recent press release, Chaston stated, “The results were super clean.” “We have created a new and powerful paradigm to get at the link between time and attention.”

Block, RA and Zakay, D. (1994). Prospective and retrospective duration judgements: A meta-analytic review. Psychonomic Bulletin & Review, 4 (2), 184-197.

Chaston, A and Kingstone, A. (2004). Time estimation: The effect of cortically mediated attention. Brain and Cognition, 55, 286-289.