Sleep Deprivation Can Threaten Competent Decision-Making, Judicial Sleepiness Regarded With High Level Of Negativity

Main Category: Sleep / Sleep Disorders / Insomnia
Article Date: 04 May 2007 - 12:00 PDT

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Gambling is a risky activity that can potentially result in the loss of a significant amount of money. Sleep deprivation can adversely affect a person's decision-making at a gambling table by elevating the expectation of gains and making light of one's losses following risky decisions.

To understand the neural underpinnings of risky decision making under conditions of sleep deprivation, Vinod Venkatraman and colleagues of Duke University studied healthy volunteers as they underwent functional magnetic resonance imaging (fMRI), the use of MRI to measure the haemodynamic response related to neural activity in the brain or spinal cord of humans.

The authors found that the nucleus accumbens, an area in the brain involved with the anticipation of reward, becomes selectively more active when high risk-high payoff choices were made under conditions of sleep deprivation. Further, the number of high risk decisions did not increase with sleep deprivation, but the expectation of being rewarded for making the high risk gamble was elevated. Allied to this finding was the observation that there was an attenuated response to losses in the insula, a part of the brain involved with evaluating the emotional significance of an event.

According to the authors, the new findings build on prior research that has shown that sleep-deprived participants choose higher-risk decks and exhibit reduced concern for negative consequences when performing a variant of the Iowa Gambling Task. While well-rested participants learn to avoid high-risk decks and to choose from the advantageous decks, sleep-deprived participants tend to continue to choose from the risky decks as the game progresses.

Michael W.L. Chee, one of the authors of the study, noted that disadvantageous decisions were not actually made, but the brain showed response patterns suggesting that going down that path might be the next step. Herein lies the added value of brain imaging - potentially being able to foretell the likelihood of making disadvantageous decisions, added Chee.

"Most of us know of people who have stayed up all night on a gambling table, taking crazy risks that did not make sense and who lost more than they had because they did not walk out when it was sensible to," said Chee. "Understanding why we make poorer choices when sleep deprived is important not only because of the increasing numbers of persons affected, but also because there exist today unprecedented opportunities to incur damaging losses by means such as online gambling. This work is one of many evaluating the neural correlates of decision making but the first to apply such methods to sleep deprived individuals."

A High Level of Negativity Towards Judicial Sleepiness

While sleepiness among judges and other members of the judiciary is not uncommon, it is viewed unfavorably by the media, society and the judicial system as a whole.

Ronald R. Grunstein, MD, PhD, of Sydney, Australia, conducted an in-depth qualitative review of media and Internet reports on judicial sleepiness.

One of the more well-known cases that Grunstein pointed out is a story that was first reported by the Daily Telegraph, a Sydney morning newspaper, in March 2005, which involved Ian Dodd, a 56-year-old judge in Sydney who had been reported to the State Judicial Commission for allegedly repeatedly falling asleep while listening to witness testimony and legal arguments. The Daily Telegraph, in a sequence of investigative articles, reported a lengthy list of Judge Dodd's sleep episodes between 2002-2004 that appeared to affect court proceedings. In late 2004, Judge Dodd obtained a medical consultation regarding his sleepiness, was diagnosed with obstructive sleep apnea, and was apparently treated effectively. There were no reported sleep episodes following commencement of treatment. However, the investigation that resulted from the ongoing press reports about his sleepiness during trials ultimately forced the judge to retire, a move that seemed to end the media frenzy.

In April 2005 and July 2006, Grunstein researched and found an additional 14 recent cases of judicial sleepiness similar to the Dodd case had been reported by the media in recent years.

According to Grunstein, these examples highlight the role of the media seeking a disciplinary approach to occupational sleepiness.

"Judicial sleepiness is clearly seen by the community as undermining their confidence in the judicial process. Regulatory processes and health screening to ensure the fitness for duty of the judiciary, legal counsel, and even juries, including the active monitoring of the judiciary for sleepiness and sleep disorders, may be required to ensure that confidence is maintained in the judicial system in the future," said Grunstein.

Chronic Fatigue Syndrome Impairs a Person's Slow Wave Activity During Sleep

Chronic fatigue syndrome (CFS) has been associated with altered amounts of slow wave sleep, which could reflect reduced electroencephalograph (EEG) activity and impaired sleep regulation. CFS is also associated with a blunted slow wave activity (SWA) response to sleep challenge, suggesting an impairment of the basic sleep drive and homeostatic response.

The study, authored by Roseanna Armitage, PhD, and colleagues at the University of Michigan, focused on 13 pairs of identical twins discordant for CFS. Analyses, which were restricted to the first four non-REM periods each night in order to show comparability, revealed that SWA, or other sleep EEG measures, did not differ between the CFS and healthy twins during a regular night's sleep. According to Armitage, it was only after a "challenge" to sleep regulation was introduced (keeping them awake an extra four hours) that the CFS twins exhibited significantly less SWA power in the first non-REM period of recovery sleep and accumulated a smaller percentage of SWA in the first non-REM period than their twin counterparts.

"CFS shares symptoms with depression, and some experts have suggested that it is not a distinctly different disorder," said Armitage. "We have also conducted studies of SWA response to sleep challenge in depression, and the results are very different. Depressed women did not show a blunted SWA response to sleep challenge. The present CFS study included only women, and none had current depression. Therefore, our results cannot be explained on the basis of depression."

BiP Levels in Animals Can Determine the Amount of Recovery Sleep Needed Following Prolonged Wakefulness

Microarray studies have identified numerous genes that change in response to prolonged wakefulness. Determining which transcriptional changes translate into protein changes that are critical for recovery during sleep loss, however, can be challenging. Immunoglobulin binding protein (BiP), a key indicator of endoplasmic reticulum (ER) stress, is instrumental in determining the amount of recovery sleep following enforced wakefulness.

The study, conducted by Nirinjini Naidoo, PhD, and colleagues at the University of Pennsylvania, focused on a Drosophila head and brain. The authors discovered that there are substantial increases in the molecular chaperone BiP in Drosophila head and brain after modest periods of sleep deprivation. These increases decline progressively during recovery sleep. However, even after 24 hours following sleep deprivation, there is still a small but significant increase in BiP.

According to Naidoo, changes in BiP levels also affect the amount of recovery sleep following sleep deprivation, although the precise mechanism by which this occurs remain to be elucidated.

"Acute sleep deprivation leads to cellular stress and possibly to low level brain injury," said Naidoo. "Activation of the unfolded protein response is one protective mechanism against such injury. If protective mechanisms, such as the unfolded protein response, are attenuated, then following sleep deprivation, animals need to sleep more to recover."

Experts recommend that adults get between seven and eight hours of sleep each night to maintain good health and optimum performance.

Those who think they might have a sleep disorder are urged to discuss their problem with their primary care physician, who will issue a referral to a sleep specialist.

SLEEP is the official journal of the Associated Professional Sleep Societies, LLC, a joint venture of the American Academy of Sleep Medicine (AASM) and the Sleep Research Society.

SleepEducation.com , a Web site maintained by the AASM, provides information about the various sleep disorders that exist, the forms of treatment available, recent news on the topic of sleep, sleep studies that have been conducted and a listing of sleep facilities.

http://www.aasmnet.org
http://www.SleepEducation.com

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