Table 1.
Studies examining slow wave activity in typical development in relation to motor, memory, or cognition
| First author, year | Sample characteristicsa | Study design, total sleep time mean (SD)b | Sleep recordingc | Sleep measure(s)d | Domain(s), taske | Main findings |
|---|---|---|---|---|---|---|
| Horváth, 2018 | 3 months n=45:15M, 30F sleep analysis n=15 |
Experimental nap: 41 (21.5) min | PSG, 6 EEG channels (F3, F4, C3, C4, O1, O2) | Spectral analysis, SWA (1- 4.5 Hz) | Memory, habituation (visual paired comparison) | SWA was not associated with habituation. |
| Simon, 2017 | 6.5 (6-7) months n=37 sleep analysis n=21 |
Experimental nap: 64 (33.3) min | PSG, 6 EEG channels (F3, F4, C3, C4, O1, O2) | Spectral analysis, SWA (1- 4.5 Hz) | Memory, encoding & retention (artificial language) | Greater absolute frontocentral SWA was associated with increased retention for extracted words. |
| Satomaa, 2020 | 7.9 (7.4 - 9) months n=56: 24M, 32F |
Observational overnight: 543 (50.3) min |
PSG, 6 EEG channels (F4, C4, F3, C3, O2, C1) | Spectral analysis, SWA (low, 0.75-1.75 Hz; total, 0.75-4.0 Hz) | Fine motor, cognitive
ability (Bayley-III) |
Higher left frontal and occipital SWA correlated with infants’ fine motor. Higher right occipital SWA correlated with infants’ cognitive ability. |
| Friedrich, 2015 | 12 (9-16) months n=90: 52M, 38F sleep analysis n=36 |
Experimental nap: 45 (21) min | PSG, 6 EEG channels (F3, F4, C3, C4, P3, P4) | Spectral analysis, SWA (.6- 4 Hz) | Memory, retention & generalization (specific vs category) | SWA was not associated with infant’s retention for generalized word meaning. |
| Page, 2018 | 20 (12-30) months n=30: 14M, 16F |
Observational nap: 77 min | 128 EEG channels | Spectral analysis, SWA (0.5-2 Hz) | Fine motor, cognitive ability (MSEL) | Increased frontal and posterior SWA was correlated with fine motor ability. SWA was not associated with cognitive ability. |
| Lokhandwala, 2021 | 51.2 (36 -71) months n=22: 15M, 7F |
Experimental nap: 94 (13.2) min | PSG, 32 EEG channels | Amplitude density- SWA (0.5-4 Hz) | Memory, immediate & delayed recall (storybook task) | Longer SWS duration was associated with better immediate post-nap recall for story sequences. |
| Kurdziel, 2018 | 51.5 (34 - 64) months n=49: 19M, 30F sleep analysis n=20 |
Experimental nap: 71 (22.9)
min overnight: 522 (71.3) min |
PSG, EEG 32 or 7 EEG channels (F3, F4, Cz, C3, C4, O1, O2) | Spectral analysis, SWA (0.5-4 Hz) | Memory, accuracy & recall (positive & negative stimuli) | SWA during nap was associated with memory decay for positive stimuli. Higher SWA during daytime nap, predicted the overnight improvement in memory. |
| Cremone, 2017 | 55.4 (37-69) months n=43: 25M, 18F sleep analysis n=11 |
Experimental nap: 69 (16.2) min | PSG, 32 EEG channels | Spectral analysis, SWA (0.5-4 Hz) | Memory, response time & congruency (dot probe task) | Greater SWA was associated with faster response times, but was not associated with congruency for emotional stimuli. |
| Zinke, 2017 | 10 (8-12) years n=25: 11M, 14F |
Experimental overnight: 576 (8.5) min | PSG, 9 EEG channels (F3, Fz, F4, C3, Cz, C4, P3, Pz, P4) | Spectral power, whole night or the first 60 minutes, SWA (0.6 - 4 Hz) | Memory accuracy, speed & retrieval (serial reaction time test); Vigilance, retrieval time (psychomotor vigilance task) | Greater SWA mean power density was associated with faster retrieval time for a novel sequence. |
| Astill, 2014 | 10.7 years n=30: 11M, 19F |
Experimental overnight: 432 (4.6) min | PSG, 2 EEG channels (FPz, Cz) | Automated slow wave detection-duration, amplitude, and density | Memory, speed & accuracy (finger tapping task) | Higher percent of SWS was associated with the overnight improvement in accuracy. Children with faster slow waves had the fastest performance. |
Studies are ordered by mean participant age.
Sample characteristics- Mean age (range, when provided); sample size, sex: M, males; F, females; Unless indicated, the reported study sample reflects the numbers of participants included in the sleep analysis (EEG/PSG).
Study design, total sleep time- Research studies are listed as experimental or observational, and followed by a description of when sleep was collected (nap or overnight sleep), and if the study collected multiple sleep recordings this is also shown. The total sleep time is shown in minutes, and listed as mean and standard deviation (when provided) or the range.
Sleep recording- PSG, polysomnography; EEG, electroencephalogram, EEG channels used in the analysis
Sleep measures- Only the slow wave activity features relevant for this review are reported. SWA, slow wave activity; SWS, slow wave sleep
Behavioral measures- Only motor, memory and/or cognitive domains relevant for this review are reported. Bayley-III, Bayley Scales of Infant and Toddler Development; MSEL, Mullen Scales of Early Learning.