Contrasting Effects of Sleep Restriction, Total Sleep Deprivation, and Sleep Timing on Positive and Negative Affect

Abstract

Laboratory-based sleep manipulations show asymmetries between positive and negative affect, but say little about how more specific moods might change. We report extensive analyzes of items from the Positive and Negative Affect Scale (PANAS) during days following nights of chronic sleep restriction (6 h sleep opportunity), during 40 h of acute sleep deprivation under constant routine conditions, and during a week-long forced desynchrony protocol in which participants lived on a 28-h day. Living in the laboratory resulted in medium effects sizes on all positive moods (Attentiveness, General Positive Affect, Joviality, Assuredness), with a general deterioration as the days wore on. These effects were not found with negative moods. Sleep restriction reduced some positive moods, particularly Attentiveness (also General Positive), and increased Hostility. A burden of chronic sleep loss also led to lower positive moods when participants confronted the acute sleep loss challenge, and all positive moods, as well as Fearfulness, General Negative Affect and Hostility were affected. Sleeping at atypical circadian phases resulted in mood changes: all positive moods reduced, Hostility and General Negative Affect increased. Deteriorations increased the further participants slept from their typical nocturnal sleep. In most cases the changes induced by chronic or acute sleep loss or mistimed sleep waxed or waned across the waking day, with linear or various non-linear trends best fitting these time-awake-based changes. While extended laboratory stays do not emulate the fluctuating emotional demands of everyday living, these findings demonstrate that even in controlled settings mood changes systematically as sleep is shortened or mistimed.

Keywords: affect; circadian rhythm; emotion; forced desynchrony; mood; sleep deprivation; sleep restriction.

FIGURE 1

Schematic representation of the sleep restriction-sleep extension protocol. All participants completed two sleep opportunity condition sessions. In both sessions, participants were scheduled to sleep at their habitual times for two consecutive nights and then to extended (10 h) or restricted (6 h) sleep opportunities for 7 consecutive days. This then was followed by a sleep deprivation under constant routine conditions (see Duffy and Dijk, 2002) and a recovery sleep opportunity. Black boxes indicate the timing of the cognitive assessments (Lo et al., 2012).

FIGURE 2

Schematic representation of the Forced Desynchrony protocol. After two baseline days participants were scheduled to a 28-h sleep wake cycle by extending the sleep opportunity to 9h:20 min and the wake period to 18h:40 min. Light intensity was low during wake periods. During each wake period 6 assessments of cognition and mood (black boxes) were conducted. The melatonin rhythm (not shown) cannot follow the 28-h sleep-wake cycle and oscillates at it near 24-h intrinsic period. As a consequence, mood assessments occur at different circadian times (Santhi et al., 2016).

FIGURE 3

Effects of sleep restriction and extension on Negative Mood (General Negative Affect, Fearfulness, Guilt, Hostility) across protocol days and mood assessment time points.

FIGURE 4

Effects of sleep restriction and extension on Positive Mood (General Positive Affect, Assuredness, Joviality, Attentiveness) across protocol days and mood assessment time points.

FIGURE 5

Effects of prior sleep restriction and extension on Negative Mood (General Negative Affect, Fearfulness, Guilt, Hostility) across 38 h of wakefulness.

FIGURE 6

Effects of prior sleep restriction and extension on Positive Mood (General Positive Affect, Assuredness, Joviality, Attentiveness) across 38 h of wakefulness.

FIGURE 7

Effects of circadian phase on Negative mood (General Negative Affect, Fearfulness, Guilt, Hostility) across a week-long 28 h Forced Desynchrony protocol.

FIGURE 8

Effects of circadian phase on Positive mood (General Positive Affect, Assuredness, Joviality, Attentiveness) across a week-long 28hr Forced Desynchrony protocol.

FIGURE 9

Effect sizes of sleep manipulations on Negative and Positive moods. Where rectangles contain * the effects reach or exceed conventional levels of significance (i.e. p < 0.5).