Sleep deprivation alters pupillary reactivity to emotional stimuli in healthy young adults

The aim of this pilot study was to quantify the impact of sleep deprivation on psychophysiological reactivity to emotional stimuli. Following an adaptation night of sleep in the lab, healthy young adults were randomly assigned to either one night of total sleep deprivation or to a normal sleep control condition. The next afternoon, responses to positive, negative, and neutral picture stimuli were examined with pupillography, an indicator of cognitive and affective information processing. Only the sleep-deprived group displayed significantly larger pupil diameter while viewing negative pictures compared to positive or neutral pictures. The sleep-deprived group also showed anticipatory pupillary reactivity during blocks of negative pictures. These data suggest that sleep deprivation is associated with increased reactions to negative emotional information. Such responses may have important implications for psychiatric disorders, which may be triggered or characterized by sleep disturbances.     

Impact of sleep restriction versus idealized sleep on emotional experience,reactivity and regulation in healthy adolescents

Sleep loss is associated with affective disturbances and disorders; however, there is limited understanding of specific mechanisms underlying these links, especially in adolescence. The current study tested the effects of sleep restriction versus idealized sleep on adolescents’ emotional experience, reactivity and regulation (specifically cognitive reappraisal). Following 1 week of sleep monitoring, healthy adolescents (n = 42; ages 13–17 years) were randomized to 1 night of sleep restriction (4 h) or idealized sleep (9.5 h). The following day, adolescents provided self‐reports of affect and anxiety and completed a laboratory‐based task to assess: (1) emotional reactivity in response to positive, negative, and neutral images from the International Affective Picture System (IAPS); and (2) ability to use cognitive reappraisal to decrease negative emotional responses. Large effects were observed for the adverse impact of sleep restriction on positive affect and anxiety as well as a medium‐sized effect for negative affect, compared to the idealized sleep condition. Subjective reactivity to positive and neutral images did not differ between the groups, but a moderate effect was detected for reactivity to negative images whereby sleep‐restricted teens reported greater reactivity. Across both sleep conditions, use of cognitive reappraisal down‐regulated negative emotion effectively; however, sleep restriction did not impact upon adolescents’ ability to use this strategy. These findings add to a growing body of literature demonstrating the deleterious effects of sleep restriction on aspects of emotion and highlight directions for future research in adolescents.     

Toddler's self‐regulation strategies in a challenge context are nap‐dependent

Early childhood represents a time of developmental changes in both sleep and self‐regulation, a construct reflecting the ability to control one's behaviour, attention and emotions when challenged. Links between sleep and self‐regulation processes have been proposed, but experimental evidence with young children is lacking. In the current study, we tested the effects of acute sleep restriction (nap deprivation) on toddlers’ self‐regulation. Healthy children (n = 12; four males; aged 30–36 months (33.9 ± 1.7)) slept on a strict schedule (verified with actigraphy and sleep diaries) for 5 days before each of two afternoon assessments following a nap and a no‐nap condition (~11‐day protocol). Children were videotaped while attempting an unsolvable puzzle, and 10 mutually exclusive self‐regulation strategies were later coded. On average, children lost ~90 min of sleep on the no‐nap versus the nap day. Nap deprivation resulted in moderate‐to‐large effects on self‐regulation strategies, with decreases in scepticism (d = 0.77; 7% change), negative self‐appraisal (d = 0.92; 5% change) and increases in physical self‐soothing (d = 0.68; 10% change), focus on the puzzle piece that would not fit (perseveration; d = 0.50; 9% change) and insistence on completing the unsolvable puzzle (d = 0.91; 10% change). Results suggest that sleep serves an important role in the way that toddlers respond to challenging events in their daily lives. After losing daytime sleep, toddlers were less able to engage effectively in a difficult task and reverted to less mature self‐regulation strategies than when they were well rested. Over time, chronically missed sleep may impair young children's self‐regulation abilities, resulting in risk for social–emotional, behavioural and school problems.     

Differential Effects of REM Sleep on Emotional Processing: Initial Evidence for Increased Short-term Emotional Responses and Reduced Long-term Intrusive Memories

ABSTRACT

Background: Rapid eye movement (REM) sleep has been postulated to facilitate emotional processing of negative stimuli. However, empirical evidence is mixed and the conditions under which higher amounts of REM sleep lead to decreased or increased emotional responses are unclear. We proposed that the time course between REM sleep and measurement of emotional responses is a crucial factor and hypothesized that more REM sleep will enhance emotional responses shortly after sleep, but will lead to decreased emotional responses in the long-term.

Participants and Methods: Seventy-six healthy young women watched negative and neutral pictures before a polysomnographically-recorded nap including three different groups (1: no REM sleep, 2: REM sleep awakening, 3: REM sleep). Short-term emotional responses were measured using aversiveness ratings of negative pictures; aversiveness ratings of intrusive picture memories on the three subsequent evenings were used to measure long-term emotional responses.

Results: For short-term emotional responses, no significant interaction indicating group differences was found. However, we found correlations between longer REM sleep duration and higher aversiveness ratings of negative pictures. In contrast, lower aversiveness of intrusive picture memories after two days was found in participants with a full REM sleep period compared to individuals without REM sleep. Correlational analyses also supported this pattern of results.

Conclusions: Results suggest that REM sleep may increase reactivity to emotional stimuli in the short-term and this effect of REM sleep appears to facilitate emotional processing during subsequent nights leading to reduced intrusive picture memories in the long-term.     

Startle modulation during conscious emotion regulation is arousal-dependent

Conscious regulation of negative emotion has been shown to affect human eyeblink startle responses, but whether these results depend on modulation of arousal- or valence-based processes is unknown. The authors presented participants with negative, neutral, and positive pictures and directed them to enhance, maintain, and suppress emotional responses. On emotional picture trials, startle responses decreased as a function of cue in the following order: enhance > maintain > suppress. Analysis of negative and positive picture trials separately revealed similar patterns of startle modulation by emotion regulation. There were no effects of emotion regulation on neutral trials. Results indicate that arousal, not valence, may be critical to startle modulation via conscious emotion regulation.     

Effect of sleep deprivation on emotional working memory

The emotional dysregulation and impaired working memory found after sleep loss can have severe implications for our daily functioning. Considering the intertwined relationship between emotion and cognition in stimuli processing, there could be further implications of sleep deprivation in high‐complex emotional situations. Although studied separately, this interaction between emotion and cognitive processes has been neglected in sleep research. The aim of the present study was to investigate the effect of 1 night of sleep deprivation on emotional working memory. Sixty‐one healthy participants (mean age: 23.4 years) were either sleep deprived for 1 night (n = 30) or had a normal night’s sleep (n = 31). They performed an N‐back task with two levels of working memory load (1‐back and 3‐back) using positive, neutral and negative picture scenes. Sleep deprivation, compared with full night sleep, impaired emotional working memory accuracy, but not reaction times. The sleep‐deprived participants, but not the controls, responded faster to positive than to negative and neutral pictures. The effect of sleep deprivation was similar for both high and low working memory loads. The results showed that although detrimental in terms of accuracy, sleep deprivation did not impair working memory speed. In fact, our findings indicate that positive stimuli may facilitate working memory processing speed after sleep deprivation.     

Temporal course of emotional negativity bias: an ERP study

There is considerable evidence that people are especially sensitive to emotionally negative materials. However, the temporal course of the negativity bias is still unclear. To address this issue, we observed the changes of P2, late positive components (LPC) and lateralized readiness potential (LRP) under positive, negative and neutral conditions, with International Affective Picture System (IAPS) pictures as emotional stimuli. We found that the amplitude of P2 in the negative block was significantly larger than that in the positive block, indicating that the attentional negativity bias occured very early in emotion perception. The LPC amplitude evoked by negative pictures was larger than that by positive and neutral pictures, suggesting that the negativity bias also occurred in a later evaluation stage of emotion processing. The response-locked LRP interval was shortest in the block of negative pictures, indicating that the negative contents elicited a reaction priming effect. Above all, this research showed that emotional negativity bias could occur in several temporal stages distinguished by attention, evaluation and reaction readiness periods.     

The impact of five nights of sleep restriction on emotional reactivity

An inadequate amount of sleep can negatively affect emotional processing, causing behavioural and neurofunctional changes. However, unlike the condition of total sleep deprivation, which has been extensively studied, the effects of prolonged sleep restriction have received less attention. In this study, we evaluated, for the first time, the effects of five nights of sleep restriction (5 hr a night) on emotional reactivity in healthy subjects. Forty‐two subjects were selected to participate, over two consecutive weeks, in two experimental conditions in counterbalanced order. The subjects were tested the morning after five nights of regular sleep and after five consecutive nights of sleep restriction. During the test, participants evaluated valence and arousal of 90 images selected from the International Affective Picture System. The subjects perceived pleasant and neutral pictures in a more negative way in the sleep‐restriction condition compared to the sleep condition. This effect survived after removing the contribution of mood changes. In contrast, there was no significant difference between conditions for ratings of unpleasant pictures. These results provide the first evidence that an inadequate amount of sleep for five consecutive nights determines an alteration of the evaluation of pleasant and neutral stimuli, imposing a negative emotional bias. Considering the pervasiveness of insufficient sleep in modern society, our results have potential implications for daily life, as well as in clinical settings.     

An event-related potential study of the processing of affective facial expressions in young children who experienced maltreatment during the first year of life

This investigation examined the effects of maltreatment during the first year of life on the neural correlates of processing facial expressions of emotion at 30 months of age. Event-related potentials (ERPs) in response to children passively viewing standardized pictures of female models posing angry, happy, and neutral facial expressions were examined. Four ERP waveform components were derived: early negative (N150), early positive (P260), negative central (Nc), and positive slow wave (PSW). Differences in these waveforms between a group of 35 maltreated and 24 nonmaltreated children were reported. The groups did not differ on the early perceptual negative component (N150), whereas the maltreated children had greater P260 amplitude at frontal leads compared to the nonmaltreated children in response to viewing angry facial expressions. For the Nc component, the nonmaltreated comparison children exhibited greater amplitude while viewing pictures of happy faces compared to angry and neutral faces, whereas the maltreated children showed greater Nc amplitude at central sites while viewing angry faces. For the PSW, the nonmaltreated group showed a greater area score in the right hemisphere in response to viewing angry facial expressions compared to the maltreated group. The results are discussed in terms of brain development and function, as well as their implications for the design and evaluation of preventive interventions.     

The influence of attachment representation on parental perception and interpretation of infant emotions: A multilevel approach

The aim of the study was to investigate parental perception and interpretation of infant emotional expression depending on their attachment representation. Forty‐six parents' responses to infant pictures depicting positive, neutral, and negative emotions were assessed on the level of affective judgments (valence, arousal), mimic responses (facial muscle activity), and of the eyelid reflex (using the startle paradigm). Results revealed small differences between parents of different attachment representations with respect to their subjective evaluations. However, secure parents, as compared to insecure ones, showed a positive bias in their mimic responses to infant pictures. The modulation of the startle response indicated a negative evaluation of negative infant emotion expressions in dismissing parents, while an augmentation of the startle response to negative infant emotions could not be observed in secure and preoccupied parents. The findings highlight the role of attachment experiences for emotional information processing in parents and its consequences for parental behavior. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 411–423, 2010.     

Neural Processing of Threat Cues in Young Children With Attention-Deficit/Hyperactivity Symptoms

A growing literature indicates that attention deficit/hyperactivity disorder (ADHD) involves difficulty processing threat-related emotion faces. This deficit is especially important to understand in young children, as threat emotion processing is related to the development of social skills and related behavioral regulation. Therefore, the current study aimed to better understand the neural basis of this processing in young children with ADHD symptoms. Forty-seven children between 4 and 7 years of age were included in the analysis, 28 typical developing and 19 with clinically significant levels of ADHD hyperactive/impulsive symptoms. Participants completed a passive affective face-viewing task. Event-related potentials were assessed for each emotion, and parental report of child behavior and emotion regulation abilities was assessed. Children with ADHD symptoms showed altered N170 modulation in response to specific emotion faces, such that the N170 was less negative in response to fearful compared to neutral faces, whereas typically developing children showed the opposite pattern. Groups did not differ in reactivity to anger or non-threat-related emotion faces. The N170 difference in fearful compared to neutral faces correlated with reported behavior, such that less fear reactivity predicted fewer prosocial behaviors. Abnormalities in the underlying neural systems for fear processing in young children with ADHD symptoms may play an important role in social and behavioral deficits within this population.     

The effect of sleep deprivation and restriction on mood,emotion, and emotion regulation: three meta-analyses in one

Study ObjectivesNew theory and measurement approaches have facilitated nuanced investigation of how sleep loss impacts dimensions of affective functioning. To provide a quantitative summary of this literature, three conceptually related meta-analyses examined the effect of sleep restriction and sleep deprivation on mood, emotion, and emotion regulation across the lifespan (i.e. from early childhood to late adulthood).MethodsA total of 241 effect sizes from 64 studies were selected for inclusion, and multilevel meta-analytic techniques were used when applicable.ResultsThere was a moderate, positive effect of sleep loss on negative mood (g = 0.45), which was stronger for studies with younger samples, as well as a large, negative effect of sleep loss on positive mood (g = −0.94). For negative mood only, studies that used total sleep deprivation had larger effect sizes than studies that restricted sleep. After correcting for publication bias, a modest but significant negative effect for sleep loss on emotion (g = −0.11) was found; the valence of emotional stimuli did not change the direction of this effect, and type of sleep manipulation was also not a significant moderator. Finally, sleep restriction had a small, negative effect on adaptive emotion regulation (g = −0.32), but no significant impact on maladaptive emotion regulation (g = 0.14); all studies on adaptive emotion regulation were conducted with youth samples.ConclusionsSleep loss compromises optimal affective functioning, though the magnitude of effects varies across components. Findings underscore the importance of sleep for healthy affective outcomes.     

Nonemotional features suppress early and enhance late emotional electrocortical responses to negative pictures

Neural processing of emotional pictures is often indexed by two electrocortical responses: the early posterior negativity (EPN) and the late positive potential (LPP). Because emotional pictures vary in nonemotional features (e.g., composition, human content, and spatial frequency), researchers often match pictures on nonemotional features to avoid their confounding effects on the EPN and LPP. However, this matching is tedious and might be unnecessary if the confounding effects could be shown to be negligible. In an item-analysis of mean amplitudes to 400 negative to neutral pictures from the International Affective Picture System (IAPS), nonemotional features had larger effects on EPN than LPP. Picture composition suppressed the relationship between emotion and EPN. Further, data simulations showed that for small picture sets, nonemotional features inflated the correlation between emotion and LPP. Therefore, nonemotional features suppress the EPN and enhance the LPP, particularly so in small picture sets.     

Emotion and the auditory brainstem response to speech

Effects of emotion have been reported as early as 20 ms after an auditory stimulus onset for negative valence, and bivalent effects between 30 and 130 ms. To understand how emotional state influences the listener's brainstem evoked responses to speech, subjects looked at emotion-evoking pictures while listening to an unchanging auditory stimulus (danny). The pictures (positive, negative, or neutral valence) were selected from the IAPS database and controlled for dominance and arousal. Utilizing an array of measurements to assess subcortical modulation, we have found that emotion does not substantially alter brainstem alter although there is a subtle effect of background noise suppression in both emotional conditions.     

Increased corticospinal excitability induced by unpleasant visual stimuli

Pleasant and unpleasant emotional stimuli are frequently conceptualized as motivators for action. This notion was examined using focal transcranial magnetic stimulation (TMS). Ten healthy participants viewed pleasant, neutral, and unpleasant pictures from the International Affective Picture System (IAPS). During picture viewing, focal TMS was applied to the right motor cortex over the area innervating the first dorsal interosseous muscle of the left hand. Corticomotor excitability was larger while viewing negative pictures than while viewing neutral or positive images, as evidenced by greater motor evoked potentials. No difference was found between pleasant and neutral pictures. These results are consistent with models of emotion in which the neural networks underlying negative emotions have selective, direct connections to brain structures that mediate motor responses.     

The interaction of anticipatory anxiety and emotional picture processing: An event‐related brain potential study

The present study examined the interaction of anticipatory anxiety and selective emotion processing. Toward this end, a rapid stream of pleasant, neutral, and unpleasant pictures was presented in alternating blocks of threat‐of‐shock or safety, which were signaled by colored picture frames. The main finding is that pleasant pictures elicited a sustained negative difference potential over occipital regions during threat as compared to safety periods. In contrast, unpleasant and neutral picture processing did not vary as a function of threat‐of‐shock. Furthermore, in both the safety and threat‐of‐shock conditions, emotional pictures elicited an enlarged early posterior negativity and late positive potential. These data show that the activation of the fear/anxiety network exerts valence‐specific effects on affective picture processing. Pleasant stimuli mismatching the current state of anticipatory anxiety apparently draw more attentional resources.     

Age differences in perception and awareness of emotion

We investigated the effects of age and gender on emotional perception and physiology using electrodermal skin conductance response (SCR) and examined whether SCR is related to subjective perceptions of emotional pictures. Older adults found pictures to be more positive and arousing than younger participants. Older women rated pictures more extremely at both ends of the valence continuum: they rated positive pictures more positively and negative pictures more negatively. Elders were less likely to show measurable SCRs. However, magnitude of SCRs when a response occurred did not differ between young and old. Subjective ratings of emotion correlated with physiological responses in younger participants, but they were unrelated in older participants. Thus, in older adults the perception of emotional events was disconnected from the physiological state induced by emotion.     

Selective visual attention to emotional pictures: Interactions of task-relevance and emotion are restricted to the late positive potential

The temporal dynamics of top-down voluntary and bottom-up driven emotional attention are a matter of debate. Both emotion and task-relevance have been shown to affect the early posterior negativity (EPN) and the late positive potential (LPP) during the processing of emotional pictures, whereas there are mixed findings related to interactions of emotion and task-relevance. In this preregistered study, we used Bayesian models to test this interplay between emotion and task-relevance. Participants (N = 104) were presented negative, neutral, and positive International Affective Picture System (IAPS) pictures, and block-wise were asked to respond either to negative, neutral, or positive pictures, rendering one stimulus category task-relevant and the remaining stimuli task-irrelevant. Bayesian models showed evidence for the absence of interactions between task-relevance and emotion. Furthermore, models showed parallel emotion and task effects for the EPN and late stages of the LPP. Additional interactive effects were found during an early LPP interval (400 to 600 ms), with increased LPP amplitudes when emotion was rendered task-relevant. Taken together, the results revealed distinct but parallel temporal onsets of task-relevance and emotion effects, followed by task and emotion interactions in the early LPP. Thus, based on this high-powered study employing Bayesian analysis, evidence is provided that interactions between task-relevance and emotion do not emerge before the LPP time window. These results further inform theories proposing early parallel and late interactive processes of the emotional salience of stimuli and top-down attention.     

Emotional event-related potentials are reduced if negative pictures presented at fixation are unattended

Viewing of emotional pictures elicits two event-related potentials (ERPs) to emotional versus neutral pictures: an early posterior negativity (EPN) and a late positive potential (LPP). Because it is unresolved whether these indexes of emotional processing are reduced to task-irrelevant pictures at fixation, negative and neutral pictures from the International Affective Picture Set (IAPS) were shown at fixation together with 6 letters that surrounded the pictures. In separate tasks, participants were instructed to attend either the pictures or the letters. When the pictures were task relevant, results showed an EPN and LPP. In contrast, when the pictures were task irrelevant, the EPN was eliminated and the LPP reduced. Performance was high in both tasks (hit rates>87%), but somewhat better when the pictures were relevant. However, analyses showed no relationship between this performance difference and the differences in EPN and LPP between tasks. These results suggest that emotional processing of strong, negative pictures is sensitive to manipulations of attention even if the pictures are shown at fixation.     

A One-Hour Sleep Restriction Impacts Brain Processing in Young Children Across Tasks: Evidence From Event-Related Potentials

The effect of mild sleep restriction on cognitive functioning in young children is unclear, yet sleep loss may impact children's abilities to attend to tasks with high processing demands. In a preliminary investigation, six children (6.6–8.3 years of age) with normal sleep patterns performed three tasks: attention (“Oddball”), speech perception (consonant–vowel syllables), and executive function (Directional Stroop). Event-related potentials (ERPs) responses were recorded before (Control) and following 1 week of 1-hour per day of sleep restriction. Brain activity across all tasks following Sleep Restriction differed from activity during Control Sleep, indicating that minor sleep restriction impacts children's neurocognitive functioning.