Sleep Promotes Consolidation of Emotional Memory in Healthy Children but Not in Children with Attention-Deficit Hyperactivity Disorder

Abstract

Fronto-limbic brain activity during sleep is believed to support the consolidation of emotional memories in healthy adults. Attention deficit-hyperactivity disorder (ADHD) is accompanied by emotional deficits coincidently caused by dysfunctional interplay of fronto-limbic circuits. This study aimed to examine the role of sleep in the consolidation of emotional memory in ADHD in the context of healthy development. 16 children with ADHD, 16 healthy children, and 20 healthy adults participated in this study. Participants completed an emotional picture recognition paradigm in sleep and wake control conditions. Each condition had an immediate (baseline) and delayed (target) retrieval session. The emotional memory bias was baseline–corrected, and groups were compared in terms of sleep-dependent memory consolidation (sleep vs. wake). We observed an increased sleep-dependent emotional memory bias in healthy children compared to children with ADHD and healthy adults. Frontal oscillatory EEG activity (slow oscillations, theta) during sleep correlated negatively with emotional memory performance in children with ADHD. When combining data of healthy children and adults, correlation coefficients were positive and differed from those in children with ADHD. Since children displayed a higher frontal EEG activity than adults these data indicate a decline in sleep-related consolidation of emotional memory in healthy development. In addition, it is suggested that deficits in sleep-related selection between emotional and non-emotional memories in ADHD exacerbate emotional problems during daytime as they are often reported in ADHD.

Transcranial Oscillatory Direct Current Stimulation During Sleep Improves Declarative Memory Consolidation in Children With Attention-deficit/hyperactivity Disorder to a Level Comparable to Healthy Controls

“…As recently shown, slow wave activity (SWA, 1e4.5 Hz) during SWS is altered in children suffering from ADHD: while over central positions the SWA was enhanced, it was attenuated by trend over frontal positions [35]. Our previous studies pointed to a reduced frontal brain function as the cause of the impaired memory consolidation during sleep in ADHD [34,36,37]. Therefore, the aim of the present study was to show that an enhancement of frontal SO activity at 0.75 Hz by toDCS during sleep enhances declarative memory consolidation in ADHD to a level comparable to that of healthy controls.…”

“…In our previous studies, we controlled for sleep/wake states and observed deficits in sleep-dependent consolidation of long-term declarative memory (picture recognition) in ADHD. Most strikingly, reduced memory performance in ADHD after sleep was linked to SO activity during sleep [34,37].…”

Opposite Impact of REM Sleep on Neurobehavioral Functioning in Children with Common Psychiatric Disorders Compared to Typically Developing Children

“…(2) In opposition, the proportion of REM sleep in typically developing children (TDC) correlated negatively with inattention and positively with performance IQ (Kirov et al, 2011). Similarly, another recent study showed that whereas in youths with ADHD, theta (4–8 Hz) EEG power during REM sleep correlated negatively with emotional memory consolidation, in healthy individuals, this correlation was positive (Prehn-Kristensen et al, 2013). Collectively, these latter findings suggest at least a bi-directional role of REM sleep and its physiology, depending on presence or absence of ADHD psychopathology.…”

REM sleep and emotional face memory in typically-developing children and children with autism

“…Theta EEG activity recorded from central cortical regions, related to face memory itself, should be distinguished from posterior theta activity, which is rather related to the processing of facial emotional expression (Guntekin & Basar, 2009). Frontal theta activity in REM sleep is positively correlated with emotional memory in typically-developing children, but the inverse is seen in children with attention deficit and hyperactivity disorder (Prehn-Kristensen et al, 2013).…”

“…REM sleep (Fogel, Smith, & Beninger, 2009;Prehn-Kristensen et al, 2013). Sleep also improves recognition of neutral faces (M. A.…”