Lack Of Sleep Affects Performance
July 28, 2012

Lack Of Sleep Can Hamper A Person’s Performance And Speed

redOrbit Staff & Wire Reports - Your Universe Online

Bad news for anyone not getting the recommended eight hours worth of sleep every night: Researchers from Brigham and Women's Hospital (BWH) in Boston have found that the longer a person stays awake, the more trouble he or she will have performing certain types of tasks.

As part of the study, which was published in Thursday's online edition of the Journal of Vision, researchers from the hospital collected and analyzed data from visual search tasks from a dozen subjects over the course of one month.

During the first week of the study, all of the participants were granted between 10 and 12 hours of sleep each night to ensure they were well rested. For the remaining three weeks, they were scheduled to sleep the equivalent of 5-6 hours per night, and in an attempt to replicate the effects of jet lag, their sleep times were scheduled on a 28-hour cycle, not a 24-hour one.

The study participants were then given computer tests centered on visual search tasks, and the BWH researchers monitored how quickly the subjects could locate important information, as well as how accurately they could identify it. They discovered that the longer the participants had been awake, the longer it took them to identify the important data on the test, and that during the 12am to 6am time period, the participants (who were not aware of the time of day at any point in the study) performed their tasks less quickly than they did during the daytime hours.

"Our team decided to look at how sleep might affect complex visual search tasks, because they are common in safety-sensitive activities, such as air-traffic control, baggage screening, and monitoring power plant operations," Dr. Jeanne F. Duffy, senior author of the study and an associate neuroscientist at BWH, said in a statement. "These types of jobs involve processes that require repeated, quick memory encoding and retrieval of visual information, in combination with decision making about the information."

"This research provides valuable information for workers, and their employers, who perform these types of visual search tasks during the night shift, because they will do it much more slowly than when they are working during the day," she added. "The longer someone is awake, the more the ability to perform a task, in this case a visual search, is hindered, and this impact of being awake is even stronger at night."

The participants' performance on the accuracy portions of the test remained fairly constant throughout, even when they were slower to identify the relevant information as the week progressed. However, the hospital said that self-rated levels of sleepiness only got slightly worse during the second and third weeks, even as the subjects' performance on the visual search aspects of the trials became "significantly slower."

According to Duffy, this suggests that a person's perceived levels of exhaustion and the amount that their performance actually suffers due to a lack of sleep do not always correlate.