Sleep Deprivation

Digit Span


[IMAGE]

The task

Subjects are given telephone numbers of different lengths. They start with three six-digit numbers, and they are required to repeat these immediately. Provided they get two of the three right, the procedure is repeated with a 7 digit telephone number. This procedure continues using telephone numbers of 8, 9, 10 digits etc, until the subject gets 2 or 3 of the numbers wrong. The subject is said to have a digit span equal to the longest length of the telephone numbers that were successfully repeated.

Results

As can be seen by the bar chart above the digit span averaged 7 digits before sleep deprivation, and 7.8 seconds after sleep deprivation. This difference was found to be significant using a Wilcoxon T test (T=50, N=21, two-tailed, p less than 0.05). Non-sleep deprived controls were tested twice, 24 hours apart. There was no significant difference between the subjects two digit spans. The average on the first day was 6.8 and 6.5 on the second day.

Research conducted by Catherine Blenkinsop and Vicki Walker.

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Gary Sturt
sturtg@colchsfc.ac.uk

Copyright © 1998 Gary Sturt
This Home Page was created by WebEdit,25 March 1998
Most recent revision 25 March 1998