Working memory is like a neural memo-pad. People with higher working memory capacity can hold more items in mind whilst solving a concurrent problem or performing a distracting task. There’s been some excitement lately about the possibility that working memory can be improved through training, with knock-on benefits for IQ and academic attainment. A new study suggests such training should come with a footnote: “Improving your working memory could affect your perception of time“.
James Woehrle and Joseph Magliano divided 99 students into two groups according to whether they had high or low working memory capacity. Next, the students solved subtraction problems in their heads. They were told the maths was their primary task but an extra challenge was to solve the problems for a certain duration, as judged by their own internal sense of time: either two minutes or four minutes.
The intriguing finding is that time went faster for the students with higher working memory capacity. When tasked with doing the maths for four minutes, they tended to work for longer, estimating that the time was up later than the low working memory participants.
What was going on? Why should having more working memory speed up the passage of time? Woehrle and Magliano said the finding was consistent with a popular account of time estimation, which posits that pulses are released by an internal pacemaker and accumulate in a counter. More pulses in the counter suggests more time has passed. Crucially, this process is gated by attention. When we pay attention to time, each pulse makes it into the counter and the passage of time feels slower. By contrast, if our attention is focused elsewhere, fewer pulses make it into the counter, as if less time has passed than really has (i.e. giving the subjective feeling of time having flown).
According to Woehrle and Magliano’s Working Memory Capacity Hypothesis – the students in the current study with more working memory were able to allocate their attention almost entirely on the primary maths task. This benefited their maths performance but meant they were less vigilant of pulses accumulating in their internal clock. By contrast, the low working memory students couldn’t help but allocate some attention to the secondary time-keeping task, making them more aware of the passage of time. As a consequence the low working memory students’ time perception was actually more accurate but their maths performance suffered. The researchers said this evidence could have “profound implications in academic situations … low working memory students may ‘think’ too much about how much time they put into their school work.”
The new findings complement previous research showing that greater working memory capacity is associated with more accurate time perception, when time perception is the primary task. In this case, having more working memory allows for greater vigilance of the internal pacemaker and counter. Indeed, in the current study, the time perception of the higher working memory group was superior in a control condition in which they only had to estimate the passage of time.
Woehrle, J., and Magliano, J. (2012). Time flies faster if a person has a high working-memory capacity. Acta Psychologica, 139 (2), 314-319 DOI: 10.1016/j.actpsy.2011.12.006