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Cited by 193Transcranial Magnetic Stimulation StudiesSleep and Wakefulness ResearchAttention Deficit Hyperactivity Disorder

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

Open access
Prehn-Kristensen, Alexander, Munz, Manuel, Göder, Robert, Wilhelm, Ines, Korr, Katharina, Vahl, Wiebke, Wiesner, Christian D., Baving, Lioba·2014·Brain Stimulation
DOI 10.1016/j.brs.2014.07.036
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Abstract

BACKGROUND: Slow oscillations (<1 Hz) during slow wave sleep (SWS) promote the consolidation of declarative memory. Children with attention-deficit/hyperactivity disorder (ADHD) have been shown to display deficits in sleep-dependent consolidation of declarative memory supposedly due to dysfunctional slow brain rhythms during SWS. OBJECTIVE: Using transcranial oscillating direct current stimulation (toDCS) at 0.75 Hz, we investigated whether an externally triggered increase in slow oscillations during early SWS elevates memory performance in children with ADHD. METHODS: 12 children with ADHD underwent a toDCS and a sham condition in a double-blind crossover study design conducted in a sleep laboratory. Memory was tested using a 2D object-location task. In addition, 12 healthy children performed the same memory task in their home environment. RESULTS: Stimulation enhanced slow oscillation power in children with ADHD and boosted memory performance to the same level as in healthy children. CONCLUSION: These data indicate that increasing slow oscillation power during sleep by toDCS can alleviate declarative memory deficits in children with ADHD.

AI snapshot

Written from the paper’s full text.

TL;DR

In a double-blind crossover, 0.75 Hz transcranial oscillating direct current stimulation during early slow wave sleep enhanced slow oscillation power and prevented overnight declarative memory loss in 12 children with ADHD, bringing their consolidation to the level of 12 healthy controls. The authors conclude that externally increasing slow oscillations can alleviate sleep-dependent declarative memory deficits in ADHD.

Key findings

  • In ADHD, the sham condition showed overnight memory loss (baseline 67.5 ± 1.7% to retrieval 57.3 ± 3.0%; t(11) = 4.3, P = .001), whereas stimulation showed no loss (65.6 ± 1.6% to 66.2 ± 3.0%; t(11) = .22, P = .829); stimulation vs sham consolidation difference was P = .004, one-tailed.
  • Unstimulated ADHD had worse sleep-dependent consolidation than healthy controls (ADHD −10.2 ± 2.4 vs controls −2.3 ± 3.4; t(22) = 1.9, P = .038, one-tailed), but after stimulation the groups did not differ (ADHD 0.5 ± 2.6 vs controls −2.3 ± 3.4; t(22) = .6, P = .520).
  • Slow oscillation power in sleep stage 4 was higher after toDCS than sham (157 ± 17.4 vs 134 ± 12.7; F(1,11) = 7.3, P = .02); macro sleep parameters did not differ between nights (P > .3).
  • Control variables (mood, alertness, digit-span) showed no significant STIM effects or interactions (P > .1), except alertness was lower before encoding than retrieval overall (F(1,11) = 7.3, P = .021).

Methods

  • 12 male children with ADHD (mean age 12.1, range 10–14) and 12 healthy boys (mean age 11.9, range 9–14). ADHD completed a double-blind crossover toDCS vs sham in a sleep laboratory (three nights: adaptation, stimulation, sham, ≥1 week apart); healthy controls performed the memory task at home and did not receive toDCS per ethics committee advice.
  • Declarative memory was tested with a computer card-pair object-location task (15 pairs), encoding repeated until ≥60% correct, retrieval next morning; outcome was the difference in correctly identified locations from the last encoding round to retrieval.
  • toDCS was sinusoidal 0.75 Hz anodal stimulation at F3/F4 with mastoid references, started 4 min after first NREM stage 2, 5 × 5 min separated by 1 min. Analysis used 2 × 2 ANOVA (STIM × SESSION) for ADHD memory/control variables, t-tests between groups, 2 × 8 ANOVA (STIM × POSITION) for SO power, and t-tests for sleep architecture; alpha was .05, with the primary hypothesis tested one-tailed.

Limitations

  • Stated: the ethics committee advised against applying toDCS in healthy children, so controls slept at home and were not stimulated; authors acknowledge possible non-comparability but argue home testing may underestimate control performance and that sleep architecture, tiredness, and mood were comparable.
  • Stated: toDCS during sleep requires sophisticated technical support; benefit may not generalize to all populations (e.g., healthy elderly did not benefit in cited work), and replications and studies in other patient groups are needed.
  • Evident from the text: small samples (12 per group), all male, and healthy controls lacked stimulation and detailed EEG, so the design cannot directly test toDCS effects in controls or fully equate laboratory vs home conditions.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.brs.2014.07.036

Cites

59 of 59 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 42 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Unstimulated children with ADHD displayed worse sleep-dependent memory consolidation than healthy controls.

    “As assumed, unstimulated children with ADHD displayed worse sleep-dependent memory consolidation than healthy controls [ADHD: À10.2 Æ 2.4; controls: À2.3 Æ 3.4; t(22) ¼ 1.9, P ¼ .038,onetailed].”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Sleep-dependent memory consolidation in healthy children assessed at home is comparable to that in children with ADHD assessed in the sleep laboratory.
  • Findingown data

    There were no differences between groups with respect to baseline memory performance.

    “There were no differences between groups with respect to baseline memory performance (P > .4).”
    Quote in the paperSubstantial claim
  • Findingown data

    The ANOVA of SO power during post-stimulation intervals in ADHD did not reveal any effects.

    “The ANOVA of SO power during post-stimulation intervals in ADHD did not reveal any effects (P < .09).”
    Quote in the paperNot a substantial claim
  • Findingown data

    In children with ADHD, during sham condition, memory performance was worse than in healthy controls.

    “While children with ADHD during sham condition showed worse memory performance than healthy controls, this memory deficit vanished after applying toDCS during sleep.”
    Quote in the paperSubstantial claim
  • Findingown data

    Digit-span performance was worse in children with ADHD than in healthy controls in both encoding sessions.

    “The digitspan performance was worse in children with ADHD than in healthy controls in both encoding sessions”
    Quote in the paperNot a substantial claim
  • May combine two claims. 18
  • Classified as probably not a substantial claim. 22

  • May combine two claims.

    Findingown data

    In children with ADHD, there were no significant main effects or interactions of STIM and SESSION with respect to mood ratings (SAM) or digit-span performance.

    “In children with ADHD, there were no significant main effects or interactions of STIM and SESSION with respect to mood ratings (SAM; P > .1)or digit-span performance (P > .1;for descriptive information see Table S2 in Supplement).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Children with ADHD, in general, felt less alert before encoding compared to the retrieval session.

    “Children with ADHD, in general, felt less alert before encoding compared to the retrieval session [F(1,11) ¼ 7.3, P ¼ .021]”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    SO power was not distributed equally over the scalp.

    “The main effect POSITION [F(7,77) ¼ 12.8, P > .001]reflects that SO power was not distributed equally over the scalp”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In healthy children, there were no significant differences in mood/tiredness ratings or digit-span performance between encoding and retrieval sessions.

    “In healthy children, there were no significant differences in mood/tiredness ratings or digit-span performance between encoding and retrieval sessions (P > .09).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In children with ADHD, applying toDCS during sleep eliminated the memory deficit, bringing performance to a level comparable to healthy controls.

    “While children with ADHD during sham condition showed worse memory performance than healthy controls, this memory deficit vanished after applying toDCS during sleep.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    When comparing mood and alertness ratings between children with ADHD and healthy controls, no significant differences were found.

    “When comparing mood and alertness ratings between children with ADHD and healthy controls no significant differences were found (P > .05).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The interaction STIM x POSITION was not significant.

    “however the interaction STIM Â POSITION was not significant [F(7,77) ¼ .49,P ¼ .833].”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In children with ADHD, neither the main effect for STIM nor the interaction STIM x SESSION was significant for alertness.

    “however, neither the main effect for STIM (P ¼ .6)nor the interaction STIM Â SESSION was significant (P ¼ .9).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Only memory performance, not performance on control variables (mood, alertness, working memory), was affected by stimulation.

    “Please note that only memory performances but not the performance on any control variable (mood, alertness, or working memory performance) was affected by the stimulation.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Slow oscillations originate mainly over frontal brain regions.

    “These slow oscillations (SO) originate mainly over frontal brain regions [28e30] and orchestrate hippocampal activity during SWS.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [28e30]

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    Patients and controls did not differ with respect to age, IQ, or basic memory skills.

    “Patients and controls did not differ with respect to age, IQ, or basic memory skills (all P-values >.2; see also Table 1).”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    Sleep stages were visually scored according to standard criteria by a trained rater.

    “Sleep stages were visually scored according to standard criteria [43] by a trained rater.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [43] Rechtschaffen, 1968

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    During SWS, newly encoded declarative memory representations are reactivated, resulting in strengthened memory consolidation during sleep.

    “Hereby, newly encoded declarative memory representations are reactivated, resulting in strengthened memory consolidation during sleep [31].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [31] Molle, 2011, Slow oscillations orchestrating fast oscillations and memory consolidation, Prog Brain Res source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The order of conditions (stimulation/sham; each at least one week apart) and picture sets were counterbalanced across patients.

    “The order of conditions (stimulation/sham; each being conducted at least one week apart) and picture sets were counterbalanced across patients.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Stimulation was not felt by the participants.

    “Stimulation was not felt by the participants.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Patients were woken up by the blinded investigator at 7 a.m.

    “Patients were woken up by the blinded investigator at 7 a.m.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Unknown to the patients and the investigator, either a toDCS or a sham treatment was conducted by a briefed medical doctor.

    “Unknown to the patients and the investigator, either a toDCS or a sham treatment was conducted by a briefed medical doctor.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Memory deficits in ADHD are caused or at least exacerbated by reduced frontal brain functions.

    “which are likewise caused or at least exacerbated by reduced frontal brain functions (e.g.reduced attention, enhanced distractibility, deficits in buffering information) [10].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [10] Valera, 2005, Functional neuroanatomy of working memory in adults with attention-deficit/hyperactivity disorder, Biol Psychiatry source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    To control for possible session effects, half of the healthy children were familiarized with the parallel version of the memory task at the end of the diagnostic session.

    “To control for possible session effects that might have taken place in ADHD patients, half of the healthy children (randomly chosen) were familiarized with the parallel version of the memory task at the end of the diagnostic session.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In young healthy adults, toDCS at 0.75 Hz during SWS increased SO power and boosted sleep-dependent consolidation of declarative memory.

    “By using transcranial oscillating direct current stimulation (toDCS) at 0.75 Hz during SWS in young healthy adults, Marshall and colleagues increased SO power, resulting in boosted sleep-dependent consolidation of declarative memory [32,33].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [32] Marshall, 2006, Boosting slow oscillations during sleep potentiates memory, Nature source

      Not checked in the free run.

    • cites [33] Marshall, 2004, Transcranial direct current stimulation during sleep improves declarative memory, J Neurosci source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Slow wave activity (SWA, 1-4.5 Hz) during SWS is altered in children with ADHD: enhanced over central positions and attenuated by trend over frontal positions.

    “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].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [35] Ringli, 2013, Topography of sleep slow wave activity in children with attention-deficit/hyperactivity disorder, Cortex source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    To reliably estimate differences in sleep stages and oscillatory activity between stimulation and sham nights, all EEG epochs with distortion caused by toDCS in the stimulation night were correspondingly deleted from the sham night EEG after recording.

    “To reliably estimate differences in sleep stages and oscillatory activity between nights with stimulation and sham nights, all EEG epochs with distortion caused by toDCS in the stimulation night were correspondingly deleted from the sham night EEG after recording.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    ADHD patients only took methylphenidate but discontinued medication 48 h (approximately twelve half-lives) prior to each experimental condition.

    “ADHD patients only took methylphenidate but discontinued medication 48 h (approximately twelve half-lives) prior to each experimental condition.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    Since only children with ADHD but not healthy children received toDCS, a full-factorial ANOVA-design was not possible, and the statistical analysis was two-fold.

    “Since only children with ADHD but not healthy children received toDCS employing a full-factorial ANOVA-design was not possible, and the statistical analysis was two-fold: memory performance and control variables (SAM scales, digit-span, alertness ratings) in children with ADHD were analyzed each by a 2 Â 2 ANOVA with the within factors STIM (stimulation vs. sham) and SESSION (learning vs. Retriev”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    toDCS only at 0.75 Hz (not at 5 Hz) and applied only during sleep leads to an increase of memory consolidation.

    “In addition, there is evidence that toDCS only at 0.75 Hz (not at 5 Hz) and applied only during sleep leads to an increase of memory consolidation [32,52,53].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [32] Marshall, 2006, Boosting slow oscillations during sleep potentiates memory, Nature source

      Not checked in the free run.

    • cites [52] Kirov, 2009, Slow oscillation electrical brain stimulation during waking promotes eeg theta activity and memory encoding, Proc Natl Acad Sci U S a source

      Not checked in the free run.

    • cites [53] Marshall, 2011, Transcranial electrical currents to probe eeg brain rhythms and memory consolidation during sleep in humans, PLoS One source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Long-term memory deficits in ADHD are often ascribed to deviant encoding rather than to problems during consolidation or retrieval.

    “Children and adults suffering from ADHD are known to display long-term memory deficits [9,45] which are often ascribed to deviant encoding rather than to problems during consolidation or retrieval [6].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [6] Skodzik, 2013, Long-term memory performance in adult ADHD: a meta-analysis, J Atten Disord source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    SO synchronizes hippocampal sharp wave ripple activity and fosters integration of newly encoded hippocampus-related memories into existing neocortical memory networks.

    “SO synchronizes hippocampal sharp wave ripple activity and thus fosters the integration of newly encoded hippocampus-related memories into already existing memory networks located in the neocortex [27,31,46].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [27] Rasch, 2013, About sleep's role in memory, Physiol Rev source

      Not checked in the free run.

    • cites [31] Molle, 2011, Slow oscillations orchestrating fast oscillations and memory consolidation, Prog Brain Res source

      Not checked in the free run.

    • cites [46] Born, 2012, System consolidation of memory during sleep, Psychol Res source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    To ensure home and laboratory conditions were comparable, parents of control children were instructed to provide a quiet room with an unstimulating workplace and to prevent disturbing events during sessions.

    “To ensure that the home environment and laboratory conditions were comparable as much as possible, parents of control children were instructed to provide a quiet, room with an unstimulating workplace and to take care that no disturbing events happened during the sessions.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The therapeutic benefit of brain stimulation by modulating cortical excitability and restoring neuronal networks in psychiatric patients is increasingly evident.

    “The therapeutic benefit of brain stimulation by modulating cortical excitability and restoring neuronal networks in psychiatric patients becomes more and more evident [48e50].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [48e50]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In depression, the positive effect of tDCS can last for weeks.

    “For example, in the case of depression the positive effect of tDCS can last for weeks [51].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [51] Nitsche, 2009, Treatment of depression with transcranial direct current stimulation (TDCS): a review, Exp Neurol source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    Patients and healthy children during sham night did not differ in sleep length, efficiency, architecture, or self-rated tiredness or mood.

    “In the same way patients and healthy children during sham night did not differ in sleep length, efficiency and architecture, or in self-rated tiredness or mood.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Healthy adults, adults with schizophrenia, and children with ADHD benefited from toDCS during sleep, while elderly healthy participants did not.

    “While healthy adults [32,33], adults suffering from schizophrenia [56], and children with ADHD benefited from toDCS during sleep, elderly healthy participants did not [57].”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [32] Marshall, 2006, Boosting slow oscillations during sleep potentiates memory, Nature source

      Not checked in the free run.

    • cites [33] Marshall, 2004, Transcranial direct current stimulation during sleep improves declarative memory, J Neurosci source

      Not checked in the free run.

    • cites [56] Goder, 2013, Effects of transcranial direct current stimulation during sleep on memory performance in patients with schizophrenia, Schizophr Res source

      Not checked in the free run.

    • cites [57] Eggert, 2013, No effects of slow oscillatory transcranial direct current stimulation (TDCS) on sleep-dependent memory consolidation in healthy elderly subjects, Brain Stimul source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Due to saturation of the EEG signal during stimulation, the affected epochs (25 min in total) had to be excluded from the analysis.

    “Due to saturation of the EEG signal during the stimulation, the affected epochs (25 min in total) had to be excluded from the analysis.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Frontally applied anodal toDCS in healthy adults can improve the sleep-dependent consolidation of declarative memory.

    “As shown by Marshall and colleagues, frontally applied anodal toDCS in healthy adults can remarkably improve the sleep-dependent consolidation of declarative memory [32,33].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [32] Marshall, 2006, Boosting slow oscillations during sleep potentiates memory, Nature source

      Not checked in the free run.

    • cites [33] Marshall, 2004, Transcranial direct current stimulation during sleep improves declarative memory, J Neurosci source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductcitation

    Our stimulation method did not follow usual tDCS protocols for treatment of clinical symptoms during daytime: single session, lower current strength (0.25 mA vs 1-2 mA), and oscillating not constant above 1 mA.

    “Moreover, our stimulation method did not follow the usual tDCS protocols for the treatment of clinical symptoms during daytime as reviewed by [48,49]: a) in comparison to most other studies, we applied DC only in one single stimulation session; b) the applied current strength in our study was significantly lower than in other studies (0.25 mA vs. 1e2 mA); and c) DC stimulation in our study was not”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [48] Kuo, 2014, Therapeutic effects of non-invasive brain stimulation with direct currents (TDCS) in neuropsychiatric diseases, Neuroimage source

      Not checked in the free run.

    • cites [49] Demirtas-Tatlidede, 2013, Can noninvasive brain stimulation enhance cognition in neuropsychiatric disorders?, Neuropharmacology source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Supporting sleep-dependent memory functions might help to treat childhood ADHD more thoroughly.

    “Thus, supporting sleep-dependent memory functions might help to treat childhood ADHD more thoroughly.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Intensive physical exercise during the daytime increases endogenous slow wave activity during subsequent sleep.

    “A more practical approach, however, comes from the field of sports medicine: intensive physical exercise during the daytime increases endogenous slow wave activity during subsequent sleep [61].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [61] Dworak, 2008, Increased slow wave sleep and reduced stage 2 sleep in children depending on exercise intensity, Sleep Med source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductreasoning

    The control group performed experimental tasks at home and slept in their own bed because the ethics committee did not support stimulating healthy children by toDCS.

    “Since the ethic committee did not support the proposal to stimulate healthy children by toDCS, children of the control group performed the experimental tasks at home and also slept in their own bed.”
    Quote in the paperSubstantial claim
38 of 38

  • The paper relies on this without support.

    Sleep-dependent memory consolidation in healthy children assessed at home is comparable to that in children with ADHD assessed in the sleep laboratory.

    “In addition, 12 healthy children performed the same memory task in their home environment.”
    “Healthy controls slept at home.”

  • The paper relies on this without support.

    Prior studies on long-term memory performance often focused on encoding and retrieval on the same day, neglecting sleep's supporting role.

    “Studies concerning long-term memory performance, however, often focused on memory encoding and retrieval on the same day, thus neglecting the supporting role of sleep in memory performance.”

  • The authors state this as an assumption.

    The benefit of toDCS may change with age due to fundamental changes in sleep architecture and sleep regulation with age.

    “However, due to fundamental changes in sleep architecture and sleep regulation with age [58], it seems plausible to assume that the benefit of toDCS may also change with age [57].”

  • The paper relies on this without support.

    ADHD drugs improve the ability to encode scholastic knowledge during the daytime but their therapeutic effects vanish toward the evening due to their short half-life.

    “ADHD drugs improve the ability to encode scholastic knowledge during the daytime but their therapeutic effects vanish toward the evening due to their short half-life.”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Cognitive improvements with so-tDCS were in declarative memory and faster reaction times and decreased intra-subject variability in a motor response inhibition Go/no-go task, while no effects were observed on inhibitory processes or on intrinsic alertness and motor memory.

    “Cognitive improvements were in declarative memory (Prehn-Kristensen et al., 2014) and faster reaction times and decreased intra-subject variability in a motor response inhibition Go/no-go task, while no effects were observed on inhibitory processes or on intrinsic alertness and motor memory (Munz et al., 2015).”

    From Cognitive Neuroscience of Attention Deficit Hyperactivity Disorder (ADHD) and Its Clinical Translation (2018) · cites this paper as Prehn-Kristensen et al., 2014

  • Slow oscillatory power during deep sleep was increased with so-tDCS over lateral prefrontal cortex, indicating an enhancement of endogenous oscillatory activity.

    “Slow oscillatory power during deep sleep was increased, indicating an enhancement of endogenous oscillatory activity with the intervention.”

    From Cognitive Neuroscience of Attention Deficit Hyperactivity Disorder (ADHD) and Its Clinical Translation (2018) · cites this paper as Prehn-Kristensen et al., 2014

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Sham retrieval mean differs between results and Table 2

    Minor

    The results report a sham retrieval mean of 57.3, whereas Table 2 reports 57.4 for the same condition.

  • ADHD-versus-control memory comparison has two reported P-values

    Minor

    The results give P = .038 for the unstimulated ADHD-versus-control comparison, while Table 2 gives .036 for that comparison.

2 of 2

Cites

Flagged first, then by citations

2 of the 61 references couldn’t be matched to a known paper.

Cited by

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Related

Authors
Prehn-Kristensen, A., Munz, M., Göder, R., Wilhelm, I., Korr, K., Vahl, W., Wiesner, C. D., & Baving, L.
Affiliations
  • Christian-Albrechts-Universität zu Kiel (DE)
  • University Children's Hospital Zurich (CH)
ORCID
Venue
Brain Stimulation
Publisher
Elsevier BV
Published
2014-11
Volume
7
Issue
6
Pages
793-799
ISSN
  • 1876-4754 (ISSN-L)
  • 1935-861X
DOI
10.1016/j.brs.2014.07.036
OpenAlex
W2038661624
Semantic Scholar
29557c0df8042e8a1f53b3091db4db098c37ee5a
Cited by
176
References
61
Citations by year
2026: 7 · 2025: 14 · 2024: 9 · 2023: 11 · 2022: 14 · 2021: 22 · 2020: 17 · 2019: 25 · 2018: 16 · 2017: 9 · 2016: 18 · 2015: 12 · 2014: 2
FWCI
7.10
Type
journal article
Language
en
Open access
Licence
Locations
  • Brain stimulation (publishedVersion, cc-by-nc-nd)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Topics
  • Life Sciences › Neuroscience › Neurology › Transcranial Magnetic Stimulation Studies
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Sleep and Wakefulness Research
  • Health Sciences › Medicine › Psychiatry and Mental health › Attention Deficit Hyperactivity Disorder
Keywords
slow oscillations, slow-wave sleep, declarative memory consolidation, attention deficit hyperactivity disorder, children, object location memory, sleep-dependent memory, non-invasive brain stimulation
MeSH terms
Adolescent, Attention, Attention Deficit Disorder with Hyperactivity, Child, Double-Blind Method, Frontal Lobe, Humans, Male, Memory Disorders, Sleep, Case-Control Studies, Polysomnography, Cross-Over Studies, Transcranial Direct Current Stimulation

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