The effects of chronic sleep reduction on the performance of cognitive tasks sensitive to sleep deprivation

Abstract

In four sleep loss experiments we aimed, first, to compare performance during long-term sleep reduction with performance during short-term total sleep deprivation, and second, to measure the effects of both methods of sleep loss on ability to ignore distracting irrelevant stimuli, using a hding embedded figures test (FEFT). Logical reasoning, auditory vigdance and finding embedded figures tasks were shown to be significantly sensitive to one night's sleep deprivation. However, in one sleep reduction study subjects reduced to a mean of 5.2 hours sleep per night for 4 weeks showed no performance deficits on logical reasoning. In a second sleep reduction study subjects reduced to a mean of 4.3 hours sleep per night for 4 nights, and subjects reduced to a mean of 5.3 hours sleep per night for 18 nights, showed no performance deficits on logical reasoning or auditory vigilance, despite their reports of severe increases in subjective sleepiness and reduced concentration. Both these sleep reduction groups, though, did show decrements on the FEFT, which we interpret in terms of dearousal increasing distractibility, which the sleep-reduced subjects could not overcome with effort, as they did with the other tests.A paradox within sleep loss research is that studies on subjects having one night's total sleep deprivation show deficits on certain tasks, some lasting for 10 min or less (Donnell, 1969;Glenville, Broughton, Wing, and Wilkinson, 1978;Wilkinson, 1961; Wimmer, Hoffmann, Bonato, and Moffitt, 1992), whereas long-term sleep reduction of a few hours per night is often found to result in no performance deficit (Horne, 1988a; Horne and Wilkinson, 1985).Single experiments usually look at just one of these methods of losing sleep. In this paper our first aim was to investigate groups of subjects under different conditions of sleep loss, but using the same tests, so that comparisons between the conditions could be made. Comparisons would be between different levels of sleep reduction, and between long-term reduction and short-term total sleep deprivation. This type of comparison had previously been performed over two nights by Wilkinson (1968), using six different levels of sleep length. He found that performance deficits result when subjects have 3 h sleep over one night, or 5 h sleep over two nights, which indicates that sleep loss can accumulate. He indicated, however, that as long as

Loss of negative priming following sleep deprivation

“…One explanation might be that SD leads to a tendency to attempt to resolve ambiguity per se, whether or not that material represents target or nontarget information. This is consistent with previous findings in SD research using tasks requiring participants to select target from nontarget items from a visual array (Blagrove et al, 1995;Norton, 1970). This might also provide some clue as to why change to the NP effect following sleep loss is limited to an experimental context associated with episodic retrieval processes, where it is argued that discrimination of recent materials is critical for this effect to occur (Tipper, 2001).…”

Placebo sleep affects cognitive functioning.

“…The observed pattern of cognitive functioning on the PASAT was again consistent with what one might observe if participants had actually experienced a poor night’s sleep (Blagrove et al, 1995; Frye et al, 2004; Ratcliff & Donger, 2009; Waters & Bucks, 2011). The COWAT, however, revealed that it is possible to provide cognitive enhancement from verbal instruction on sleep quality, as the significant effect seemed to be driven largely from those in the above average group producing higher than normal scores.…”

The impact of sleep deprivation on decision making: A review.

“…The critical reasoning task was not affected by SD, suggesting that although participants were still able to assimilate the factual material generated by Masterplanner, they were unable to use this material in a constructive and innovative way. The lack of an effect on critical reasoning at this stage of SD is in keeping with the scientific literature on SD concerning logical or convergent tasks (Blagrove et al, 1995; Horne, 1988a; Naitoh, 1976; Wilkinson, 1965). Unfortunately, although tasks like Masterplanner are more applicable to the real world, they present the investigator with the difficulty of determining suitable outcome measures.…”

“…For example, Norton (1970) found that 2 nights of SD caused a marked deterioration in the detection of target information within a complex visual array. Recently, Blagrove et al (1995) found similar impairments on an embedded figures task after only 1 night of SD. Blagrove (1994Blagrove ( , 1996 has also reported that SD participants are less discriminating in handling ambiguous material, less confident, more open to leading remarks, and more willing to modify recollections of a witnessed event, particularly after negative feedback following their initial account.…”