different numbers until they had done it 20 times. In eachinstance, the man performed worse than the eight volunteers. His ability to judge the passage of time was somehow impaired.
A brain scan indicated some damage to the right frontal lobe, which as the name implies is near the front of the brain on the right. This gives us a clue as to the next area of the brain implicated in time perception, an area we would normally associate with the ability to hold something in mind known as working memory. It is this skill that allows you to read through a recipe, then remember the list of ingredients while you go to the cupboard to fetch them. The very front of the frontal lobe, the pre-frontal cortex, which is located behind the forehead, seems to be particularly crucial.
The involvement of this area of the brain in time-keeping is backed up by the curious new finding that children with Tourette’s syndrome have recently been found to be better than other children at judging durations of just over a second. 22 Suppressing their tics involves activity in the prefrontal cortex and experts have found those children with Tourette’s who were particularly good at suppressing their tics did even better on the timing tasks. This suggests that their need to use this region of the brain to control their tics brings an added advantage in terms of time perception.
So far we have looked at two areas of the brain associated with time perception – the cerebellum, low down at the back of the brain for those millisecond judgements, and the frontal lobe, behind the forehead, for durations of seconds. But what happens when we try to judge muchlonger durations of hours or even days without access to a clock or any clues as to day and night?
THE PERFECT SLEEP
Do glaciers carve their way through caves underground in the same way as they gouge through mountains above the ground? This was the question that the French speleologist Michel Siffre set out to answer when he planned an underground expedition in 1962. But having made his initial arrangements, he began to ponder a quite different question, one which was to revolutionise another field of study entirely.
He would make the trip as planned, taking all the standard equipment such as tents, ropes, lanterns and food, but would leave one item behind – his wristwatch. Instead of recording glacier measurements, he would systematically record his perceptions of time passing. He wanted to explore the natural rhythms of the body untainted by outside cues. The longest attempts to do this had at that point lasted only seven days, with both American and Soviet astronauts taking part in Cold War isolation studies to assess how people might survive in fall-out shelters after a nuclear attack. Michel had done the same, volunteering to spend a week in silent darkness in an experiment at an air force base in Ohio. Now he wanted to try it out for far longer, in more extreme conditions.
The authorities were not keen on letting a 23-year-old embark on such a risky expedition. But Michel was determined and he had form when it came to persuasion, havingconvinced a professor at the Academy of Sciences in France to take him on as a geology student when he was only 15. The difference this time was that he was putting his life at risk.
The location Michel had selected for his experiment was the Scarasson Cavern, a cave created from hundreds of horizontal layers of ice, which, unusually for a subterranean glacier, wasn’t linked to a glacier on the surface. To reach the ice cave Michel would need to descend a 130-foot shaft, part of which was S-shaped, meaning that if he were to slip on the ice and break his arm it would be impossible to haul him out; a minor fracture would result in death. Assuming he made it safely down into the cave, he planned to spend two months down there in complete isolation. He offered to sign disclaimers, freeing the authorities from any legal responsibility for his safety, but they
A brain scan indicated some damage to the right frontal lobe, which as the name implies is near the front of the brain on the right. This gives us a clue as to the next area of the brain implicated in time perception, an area we would normally associate with the ability to hold something in mind known as working memory. It is this skill that allows you to read through a recipe, then remember the list of ingredients while you go to the cupboard to fetch them. The very front of the frontal lobe, the pre-frontal cortex, which is located behind the forehead, seems to be particularly crucial.
The involvement of this area of the brain in time-keeping is backed up by the curious new finding that children with Tourette’s syndrome have recently been found to be better than other children at judging durations of just over a second. 22 Suppressing their tics involves activity in the prefrontal cortex and experts have found those children with Tourette’s who were particularly good at suppressing their tics did even better on the timing tasks. This suggests that their need to use this region of the brain to control their tics brings an added advantage in terms of time perception.
So far we have looked at two areas of the brain associated with time perception – the cerebellum, low down at the back of the brain for those millisecond judgements, and the frontal lobe, behind the forehead, for durations of seconds. But what happens when we try to judge muchlonger durations of hours or even days without access to a clock or any clues as to day and night?
THE PERFECT SLEEP
Do glaciers carve their way through caves underground in the same way as they gouge through mountains above the ground? This was the question that the French speleologist Michel Siffre set out to answer when he planned an underground expedition in 1962. But having made his initial arrangements, he began to ponder a quite different question, one which was to revolutionise another field of study entirely.
He would make the trip as planned, taking all the standard equipment such as tents, ropes, lanterns and food, but would leave one item behind – his wristwatch. Instead of recording glacier measurements, he would systematically record his perceptions of time passing. He wanted to explore the natural rhythms of the body untainted by outside cues. The longest attempts to do this had at that point lasted only seven days, with both American and Soviet astronauts taking part in Cold War isolation studies to assess how people might survive in fall-out shelters after a nuclear attack. Michel had done the same, volunteering to spend a week in silent darkness in an experiment at an air force base in Ohio. Now he wanted to try it out for far longer, in more extreme conditions.
The authorities were not keen on letting a 23-year-old embark on such a risky expedition. But Michel was determined and he had form when it came to persuasion, havingconvinced a professor at the Academy of Sciences in France to take him on as a geology student when he was only 15. The difference this time was that he was putting his life at risk.
The location Michel had selected for his experiment was the Scarasson Cavern, a cave created from hundreds of horizontal layers of ice, which, unusually for a subterranean glacier, wasn’t linked to a glacier on the surface. To reach the ice cave Michel would need to descend a 130-foot shaft, part of which was S-shaped, meaning that if he were to slip on the ice and break his arm it would be impossible to haul him out; a minor fracture would result in death. Assuming he made it safely down into the cave, he planned to spend two months down there in complete isolation. He offered to sign disclaimers, freeing the authorities from any legal responsibility for his safety, but they
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