Siffre (Sleep and dreaming)SiffreSiffre (Sleep and dreaming)
Siffre (1975) Six months alone in a cave (textbook pg.245-247)
“Understand the aims, procedures and findings (results and conclusions), strengths and weaknesses of”
Background: Siffre wanted to know what his internal body clock would be like without external cues (zeitgebers) such as clocks and sunlight. NASA was interested in the research, as they wanted to find out what it would be like for astronauts in space who would also be living without daylight, in isolation.
| A | Siffre aimed to see what his natural sleep-wake cycle was, when there are no external influences such as light. Siffre also aimed to see how astronauts would cope when travelling through space, without external zeitgebers. |
| P | Siffre went to live in a cave in Texas, America in 1972 for 6 months. He had a tent with a bed, table and chair. He had food and water. The cave was in complete darkness, lit by artificial lighting only, which was controlled by the researchers. There was no natural light and no way of telling the time (no clocks). • When he was tired and believed it was “night time” he would phone the researchers to ask them to turn the lights off. • Every time Siffre woke up from his sleep, he would phone the researchers to ask them to turn the lights on. Siffre conducted several tests on himself during the time in the cave, such as: • Blood pressure • Memory tests • Cycling 3 miles on an exercise bike He had to clean the cave daily, as the dust would have been a big risk to his health. |
| R | • Siffre became depressed due the loneliness. • His memory was negatively impacted, as was his eyesight. • Siffre did not get the days and nights right – his sleep-wake cycles were longer than 24 hours, varying from 18 to 52 hours. |
| C | Zeitgebers are important for several reasons, and their absence can impact memory and mental health. Without external cues, the sleep-wake cycle (which is usually circadian) can sometimes double in length from 24 hours to up to 52 hours. |
| G | (-) The sample was only one individual – other people may have reacted differently and demonstrated different natural sleep-wake cycles. Previous research has found that people’s sleep-wake cycles are varied lengths without light. |
| R | (+) The procedure was somewhat standardised – the same equipment could be provided to another individual, and the same controlled set-up with lighting controlled by a researcher. |
| A | (+) The results were useful to astronauts – the study showed that isolation was not good for mental health and that astronauts would need companionship. |
| V | (-) Even though Siffre controlled when the lights were on/off, this would have impacted Siffre’s internal body clock and interfered with his ‘natural’ sleep-wake cycle. (+) The study was longitudinal, taking place over 6 months, which means they could collect a large amount of data, being confident in the final outcomes. Siffre did several tests like blood pressure monitoring, memory tasks etc. so there was a lot of data about the experience. |
| E | (-) Siffre experienced psychological harm such as loneliness, depression and suicidal thoughts due to the isolation. He also experienced worsening of his eyesight and memory difficulties. |
Siffre’s Study Key Term Glossary
| Zeitgeber | An external “time giver” such as lighting or clocks |
| Circadian rhythm | An internal bodily rhythm lasting 24 hours |
| Sleep wake cycle | A circadian rhythm consisting of a period of being awake followed by a period of being asleep (totalling 24 hours) |
| Need more help? Want to stretch your understanding? |
| https://neuron.illinois.edu/files/U3_L1_Supplement_Caveman.pdf https://en.wikipedia.org/wiki/Michel_Siffre |
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