ABSTRACT
The nonsomniacs seem to have little difficulty in staying awake for long periods without harm, but this is not true for everyone. Such is the force of the pressure to sleep that few people ever stay awake for more than a single night in a whole lifetime. Psychologists have attempted to assess the effects of sleep deprivation objectively using batteries of standard tests only to discover that it is not very easy. Sleep deprivation undermines people's ability to maintain concentration on a task which they could otherwise carry out quite well. This effect is quite marked for boring tasks but may be absent if the task is important or interesting. Motivation does not disappear completely, it is merely reduced. It can still be revived by an exciting game or the arrival of a friend whose company is much enjoyed. Sleep may combine with other avoidance motives according to the situation.
