Sleep on Life Satisfaction and Cognitive Function

¶ … Sleep on Life Satisfaction and Cognitive Function

Popular literature is replete with articles presenting evidence of the many harmful effects of sleep deprivation and the general consensus is that modern society works too much and sleeps too little. To be accurate, many empirical studies do exist that demonstrate the ill effects of insufficient sleep (Shekleton, 2010). Where these studies once predominantly emanated from the field of applied psychology -- in other words, from animal studies -- today the literature contains many juried articles from reputable laboratories and sleep clinics whose research is carried out with human beings ("National Sleep Foundation," 2005). The case for the physiological importance of sleep deprivation has been made, but as Groeger, et al. (2004) argues "actual data that show that society is sleep deprived do not exist." And what sleep data there is about the impact of sleep quality and amount on perceptions about life quality is based on samples too small and too particular to be representative of the population as a whole (Groeger, et al. (2004). In the conclusions of their cross-sectional study, Groeger, et al. (2004) were strongly supportive of the impact of sleep on subjects' perceptions of the quality of their lives, finding that "whether directly or indirectly, sleep indeed has a major impact how we perceive our quality of life. It is of interest, and adds still more complexity to any putative involvement of mood as an intervening variable, that the data do not imply that more sleep is always better" (Groeger, et al., 2004). The current moods of subjects during their interviews were not assessed by Groeger, et al. (2004); however, the researchers did acknowledge that the responses obtained could be influenced by the moods of the subjects.

The interview questionnaire used by Groeger, et al. (2004) was retrospective in nature, and used closed ended questions, or Loiter scale rating. Given the literature on memory, instrumentation used in the cross-sectional study may well have been inadequate to the task of accurately measuring the daytime effects of sleep variation.

Cognitive research on memory has demonstrated that recall is influenced by the recency effect and the primacy effect. That is, when recalling lists of words, for instance, those words that were presented toward the end of the list are retained at more frequently than words presented at the beginning or middle of a list (recency effect) and those words that were presented at the beginning of the list are presumed to be more important (primacy effect). The seminal research of Miller and Campbell (1959), recorded trial proceedings that were characterized by different argument sequences were analyzed regarding how the order of "for" or "against" message content persuaded judgment. When the first and second messages were proximal, followed by a delay of a week before the judgment, a primacy effect occurred -- the first message prevailed in the judgment. When there was a delay between the first and second message, but the second message and the judgment were proximal, a recency effect occurred -- and the second message prevailed in the judgment ("ChangingMinds.Org," 2011).

Certainly, subjects in the Groeger, et al. (2004) study could be expected to recall the approximate times of going to bed and arising, particularly if they reliably kept to the same hours every day, and the maintained the same patterns across the workday and weekends. However, as the literature demonstrates, the ability of people to accurately recall less meaningful, qualitative nuance is susceptible to disruption and attentional bias. Gilbert, et al. (1988) suggest that cognitive "busyness" impacts perception about constraining factors in the behavior of others.

In summary, absent the recording of daily impressions regarding fatigue, energy, enjoyment, satisfaction, accomplishment, and mood, the reliability of the data is suspect.