Conversely, the state instability theory goes beyond the lapse hypothesis to explain performance deficits after sleep deprivation. In one study done by Doran et al. (2001), researchers hypothesized that the effect of sleep deprivation on performance could be explained by an increased homeostatic urge to sleep, which leads to more lapses in response. They presented the PVT task for TSD participants who experienced 88 hours of sleep deprivation and had a control group of NAP subjects that had two hours of sleep in every 12 hours. The state instability hypothesis was examined by comparing performance on three levels: high-signal-load, short-duration, and sustained-attention task. The researchers tried to find evidence that showed that as with
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Fatigue did not show a slower shift of selective attention, although it was expected because of the results of previous studies for vigilant attention (Belenky et al., 2003; Doran et al., 2001; Dinges & Kribbs, 1991; Williams et al., 1959). The slopes of both conjunction and spatial-configuration search RTxSet Size graphs indicated search rates that did not change and seemed to be unaffected by sleepiness, both in terms of an analysis of the circadian phase and total task time. Instead, there was an increase in the RTxSet Size y-intercept for both search tasks, which could possibly be explained by the perceptual, decision-stage, or response-stage effects of sleepiness. As Humphrey, Kramer, and Stanny (1994) provided physiological evidence that sleepiness does not affect the response stage, we are left with sleep having an effect on perceptual processes, with an inferred impact on decision processes. The researchers propose that these factors of alertness mediate attention performance downstream from selective attention, which damages decision-making. Therefore, a critical finding of the study is that the effects of the circadian pacemaker and homeostatic sleep drive affect vigilant and selective attention through separate mechanisms (Horowitz et al., …show more content…
The main functional decomposition of alertness through circadian and homeostatic types showed differential results, where circadian rhythm controls sleep and wake cycles and homeostasis mediates declining alertness. Additional differences between the type of sleep deficiency presented by chronic sleep restriction and total sleep deprivation show the possibility of sleep restoration in TSD but not CSR and the potential for human brain adaptation to chronic sleep loss at a lower efficiency level. The “lapse” and “state instability” hypotheses of the interaction attempt to explain the effect of sleep loss on attention, which were examined through different tasks that show a functional dissociation between vigilance and selection attention. Vigilant attention reaction times showed a general trend that as fatigue increases, the accuracy of the task decreases as errors increase, and overall reaction time increases as attention decreases. Contrastingly, sleep deficiency in the selective attention task showed no affects, as search rate remained constant with or without sleep loss. Going forth, the challenge for future research is finding a way to consolidate the many models that attempt to explain attention cognitive performance following sleep deficiency. Although these individual components can be separately measured, it is necessary to integrate
Fatigue did not show a slower shift of selective attention, although it was expected because of the results of previous studies for vigilant attention (Belenky et al., 2003; Doran et al., 2001; Dinges & Kribbs, 1991; Williams et al., 1959). The slopes of both conjunction and spatial-configuration search RTxSet Size graphs indicated search rates that did not change and seemed to be unaffected by sleepiness, both in terms of an analysis of the circadian phase and total task time. Instead, there was an increase in the RTxSet Size y-intercept for both search tasks, which could possibly be explained by the perceptual, decision-stage, or response-stage effects of sleepiness. As Humphrey, Kramer, and Stanny (1994) provided physiological evidence that sleepiness does not affect the response stage, we are left with sleep having an effect on perceptual processes, with an inferred impact on decision processes. The researchers propose that these factors of alertness mediate attention performance downstream from selective attention, which damages decision-making. Therefore, a critical finding of the study is that the effects of the circadian pacemaker and homeostatic sleep drive affect vigilant and selective attention through separate mechanisms (Horowitz et al., …show more content…
The main functional decomposition of alertness through circadian and homeostatic types showed differential results, where circadian rhythm controls sleep and wake cycles and homeostasis mediates declining alertness. Additional differences between the type of sleep deficiency presented by chronic sleep restriction and total sleep deprivation show the possibility of sleep restoration in TSD but not CSR and the potential for human brain adaptation to chronic sleep loss at a lower efficiency level. The “lapse” and “state instability” hypotheses of the interaction attempt to explain the effect of sleep loss on attention, which were examined through different tasks that show a functional dissociation between vigilance and selection attention. Vigilant attention reaction times showed a general trend that as fatigue increases, the accuracy of the task decreases as errors increase, and overall reaction time increases as attention decreases. Contrastingly, sleep deficiency in the selective attention task showed no affects, as search rate remained constant with or without sleep loss. Going forth, the challenge for future research is finding a way to consolidate the many models that attempt to explain attention cognitive performance following sleep deficiency. Although these individual components can be separately measured, it is necessary to integrate