People who are more aware of their own heart-beat have superior time perception skills

What underlies our sense of time? A popular account claims an internal pacemaker emits regular pulses, which are detected by an accumulator. The amount of accumulated pulses represents the amount of time that's passed.

Trouble is, this is all very theoretical and no-one really knows how or where in the brain these functions are enacted. One suggestion is that the pulses are based on bodily feedback and in particular the heart-beat. Consistent with this is a recent brain imaging study that showed activity in the insular (a brain region associated with representing internal bodily states) rose linearly as people paid attention to time intervals (pdf). Now a behavioural study by Karin Meissner and Marc Wittmann has built on these findings by showing that people who are more sensitive to their own heart-beat are also better at judging time intervals.

Thirty-one participants listened to auditory tones of either 8, 14, or 20 seconds duration. After each one, they heard a second tone and had to press a button when they thought its duration matched the first. Counting was forbidden during the task and a secondary, number-based memory task helped enforce this rule. Heart-beat perception accuracy was measured separately and simply involved participants counting silently their own heart-beats over periods of 25, 35, 45 and 60 seconds.

The take away message is that the participants who were more in tune with their heart-beats also tended to perform better at the time estimation task. A further detail is that physiological measures taken during the encoding part of the task showed that as time went on, the participants' heart-rate slowed progressively, and their skin conductance (i.e. amount of sweat on the skin) reduced. Moreover, the rate of change in a participant's heart-rate (but not skin conductance) was linked with the accuracy of their subsequent time estimates.

'These results suggest that the processing of interoceptive signals [i.e. of internal bodily states] in the brain might contribute to our sense of time,' Meissner and Wittmann concluded.

The new findings add to past research showing that patients with cardiac arrhythmia are poorer than controls at time estimation tasks, and that drug-induced speeding or slowing of the autonomic nervous system (including heart-rate) affects people's under- or over-estimation of time intervals.
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Meissner, K., and Wittmann, M. (2011). Body signals, cardiac awareness, and the perception of time. Biological Psychology, 86 (3), 289-297 DOI: 10.1016/j.biopsycho.2011.01.001

Tourette's Syndrome associated with superior timing control

Children with Tourette's Syndrome, the neurodevelopmental condition characterised by involuntary motor and verbal tics, have superior timing abilities compared with their healthy age-matched peers, a new study suggests.

Carmelo Vicario and colleagues tested nine children with Tourette's (average age 11 years) and 10 controls (average age 12) on timing perception and timing production. The former involved the children judging whether two circles were on screen for the same length of time or not. The latter task involved the children noting the time that a circle appeared on-screen and then pressing the space key on a key board for the same duration. Half the trials involved intervals in the sub-second range (from 310ms to 500ms), the other half were longer than a second, up to 1900ms.

There was no difference between the groups on timing perception or sub-second timing production. However, the children with Tourette's were more accurate at the longer 'supra-second' version of the timing production task.

Vicario's team aren't entirely sure why the children with Tourette's showed this advantage. However, past research suggests that tic suppression is associated with activity in the dorsolateral prefrontal cortex and the supplementary area - two areas which are also known to be involved in control of timing. Consistent with this, the children with less severe tics, perhaps by virtue of their greater control over those tics, also tended to be the children who most excelled at the timing production task.

The children were also tested on other factors that could be relevant, including attention and working memory, but scores on these tasks didn't correlate with performance on the timing tasks.

This new finding of enhanced timing control in Tourette's comes after a 2006 study that found children with the condition exhibited superior self-control in an eye-movement task. A study published in 2007, meanwhile, reported Tourette's was associated with superior grammatical abilities.

'The present data are in support of an enhancement of cognitive control processes in Tourette's Syndrome children, probably facilitated by effortful tic suppression,' the researchers said.
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Vicario, C., Martino, D., Spata, F., Defazio, G., Giacchè, R., Martino, V., Rappo, G., Pepi, A., Silvestri, P., & Cardona, F. (2010). Time processing in children with Tourette’s syndrome. Brain and Cognition, 73 (1), 28-34 DOI: 10.1016/j.bandc.2010.01.008

Doubt cast on the maxim that time goes faster as you get older

Time gets faster the older you are. Or does it? When William Friedman and Steve Janssen asked 49 New Zealand undergrads (average age 21) and 50 older adults (average age 68) to say how fast time passed for them, including the last week, month and year, very few differences emerged. Most participants felt time passed quickly but it was only when considering the speed of the last ten years that the older adults said time had gone by more quickly than the younger participants, and even here the effect of age was small.

This finding, and another like it involving German and Austrian participants published in 2005, casts doubt on some of the classic explanations for time speeding up with age, including William James' suggestion that time feels slower when younger because it is packed with more memorable events. If true, you'd expect the effect to apply over time periods shorter than ten years.

Friedman and Janssen's initial study also undermined a novel explanation for time speeding up known as 'telescoping'. This is the idea that time feels faster when we look back on past events and discover that we underestimated how long ago they occurred. Earlier in the study, the researchers had asked their participants to estimate when 12 newsworthy events from the past had occurred, including Saddam Hussein's capture in 2003. By giving them false feedback on their accuracy, the researchers exaggerated or reduced the telescoping effect but this didn't have any effect on participants' subsequent ratings of how fast time goes by.

A second study, conducted on the internet, tested a novel explanation for time seeming faster to some people than others: feeling rushed. Nearly two thousand Dutch participants aged between 16 and 80 rated the speed of time and how rushed they felt in life. Once again, very few age differences emerged, with only the ten-year period being judged to have passed more quickly by older participants.

Age accounted for four per cent of the variance in how quickly participants said the last ten years had passed and just one per cent of the perception of time's speed in general. By contrast, how busy and rushed people reported feeling accounted for ten per cent of the variance in subjective speed of time. Consistent with this, women reported feeling more rushed than men, on average, and they perceived time to go by more quickly.

Quite why the idea that time speeds up with age is so widely believed requires further study, the researchers said. 'Another significant question,' they continued, 'is why age differences in the subjective speed of time are found when adults are asked to consider the last ten years but not present or only very weak when they report on the last year or more recent intervals.' The effect over ten years, they suggested, could simply be the self-fulfilling effect of the cultural belief that time speeds up with age.

'The answers to these questions,' Friedman and Janssen concluded, 'may shed light on a topic that has engaged philosophers and psychologists for more than 100 years.'
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Friedman, W., & Janssen, S. (2010). Aging and the speed of time. Acta Psychologica, 134 (2), 130-141 DOI: 10.1016/j.actpsy.2010.01.004

Time flew by ... I must have been enjoying myself

Have you ever been in the cinema and felt the time drag? It's happened to me. A glance at my watch and then the thought that I can't be enjoying the film all that much or else the time would surely have flown. My experience matches the findings from a series of studies by Aaron Sackett and colleagues. The folk psychology belief 'time flies when you're having fun' is so powerful and ubiquitous, the researchers say, that whenever we feel an event has passed more quickly than we expected, we infer that we must have been enjoying ourselves, and vice versa for events that drag.

The researchers first had dozens of undergrads look through passages of text and underline any words with adjacent repeats of a particular letter. Crucially, the researchers told the participants that the task would last ten minutes, but in reality it lasted either five minutes or twenty minutes, thus creating the illusion of time flying or dragging, respectively. A sneaky switch of stop-watches helped create the illusion. Afterwards, the participants who'd experienced the sense of the time flying rated the task as far more enjoyable than did the participants who'd experienced the sense of time dragging.

Further experiments showed that provoking the feeling of time flying led participants to be more tolerant of an irritating noise, and led them to enjoy their favourite song more than usual. This last finding was important because there was a possibility that it would feel unpleasant for a pleasurable activity to end earlier than expected.

If people really do use the 'time flies when you're having fun' adage to evaluate their own enjoyment, then challenging or encouraging the truth of the adage ought to affect the kind of findings described above. That's exactly what Sackett's team found. When participants read a scientific article challenging the 'time flies' adage, speeding up their subjective sense of time no longer increased their enjoyment of a word-based task.

It was a similar story when participants were given an alternative explanation for why time might have raced by. Participants were given ear plugs, which they were told could speed people's time perception. Again, the illusion of time flying didn't lead these participants to enjoy a task more, presumably because they attributed the sense of time flying to the ear plugs rather than to their enjoyment.

'Taken together, these findings have important implications for understanding and changing hedonic experience,' the researchers said. The Digest got in touch with lead author Aaron Sackett, Marketing Professor at the University of St. Thomas, to ask him how this might apply in the real world. He said the first thing to do is minimise people's access to accurate time cues. Next, alter their subjective time perception. There are numerous ways to do this. For example, physiological arousal speeds time perception so a free coffee at the start of a long queue could work (as long as no clocks were in sight). Even music that's incongruent with the context (e.g. Chinese music in an English restaurant) has been found to speed time. Finally, you need the surprise moment, when people are alerted to the true passage of time. That provokes in people the sensation of time having flown, followed by the gratifying inference that they must therefore have been enjoying themselves.
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AM Sackett, LD Nelson, T Meyvis, BA Converse, & AL Sackett (2010). You're having fun when time flies: The hedonic consequences of subjective time progression. Psychological Science : 10.1177/0956797609354832