Inter and intrahemispheric EEG correlation as a function of sleep cycles

Patterns of Intrahemispheric EEG Asymmetry in Insomnia Sufferers: An Exploratory Study

“…Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO. In other words, we think that higher asymmetry during sleep (only in INS, not GS) may result in increases in objective-subjective discrepancy.…”

“…Our primary hypothesis, strictly limited to fronto-parietal derivations, is that INS will have higher fronto-parietal INTRA during sleep compared to GS, because frontal and parietal regions have been found to exhibit distinct patterns of INTER asymmetry in different subtypes of insomnia [28] and that many differences in EEG activity can be found in frontal derivations compared to GS [2][3][4][5][6][7]. Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO.…”

Patterns of Intrahemispheric EEG Asymmetry in Insomnia Sufferers: An Exploratory Study

“…Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO. In other words, we think that higher asymmetry during sleep (only in INS, not GS) may result in increases in objective-subjective discrepancy.…”

“…Our primary hypothesis, strictly limited to fronto-parietal derivations, is that INS will have higher fronto-parietal INTRA during sleep compared to GS, because frontal and parietal regions have been found to exhibit distinct patterns of INTER asymmetry in different subtypes of insomnia [28] and that many differences in EEG activity can be found in frontal derivations compared to GS [2][3][4][5][6][7]. Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO.…”

Inter-hemispheric asynchrony of the brain during events of apnoea and EEG arousals

“…The effect was most intense and consistently seen in δ, α and β bands. It should be noted that other researchers (Barcaro et al 1986, Corsi-Cabrera et al 1996 have reported similar results considering the δ and β bands, for subjects drawn from a normal healthy population. This study extends their results by considering all four frequency bands; in addition, the present study includes clinically diagnosed SAHS patients as well as normal subjects having symptoms of SAHS.…”

Cross-hemispheric Alternating Current Stimulation During a Nap Disrupts Slow Wave Activity and Associated Memory Consolidation

“…This occurs across low delta (1.0–2.0 Hz), alpha (9.0–10.0 Hz) and spindle (13.0–14.0 Hz) ranges during NREM sleep [36], and predominates anteriorly – in the frontal brain region – during SWS [34]. Inter-hemispheric coherence in delta-range frequencies increases in humans in the transition from wakefulness to sleep [37], and inter-hemispheric EEG correlation in the delta-range has been reported to be higher in stage 2 and stage 4 sleep than in wakefulness [38]. Inter-hemispheric synchrony of EEG oscillations between homologous brain regions of cats were reported to be permanently disrupted when the corpus callosum was sectioned [39], suggesting that connectivity between hemispheres may be functionally relevant.…”

Patterns of Intrahemispheric EEG Asymmetry in Insomnia Sufferers: An Exploratory Study

“…Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO. In other words, we think that higher asymmetry during sleep (only in INS, not GS) may result in increases in objective-subjective discrepancy.…”

“…Our primary hypothesis, strictly limited to fronto-parietal derivations, is that INS will have higher fronto-parietal INTRA during sleep compared to GS, because frontal and parietal regions have been found to exhibit distinct patterns of INTER asymmetry in different subtypes of insomnia [28] and that many differences in EEG activity can be found in frontal derivations compared to GS [2][3][4][5][6][7]. Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO.…”

Inter-hemispheric asynchrony of the brain during events of apnoea and EEG arousals

“…The effect was most intense and consistently seen in δ, α and β bands. It should be noted that other researchers (Barcaro et al 1986, Corsi-Cabrera et al 1996 have reported similar results considering the δ and β bands, for subjects drawn from a normal healthy population. This study extends their results by considering all four frequency bands; in addition, the present study includes clinically diagnosed SAHS patients as well as normal subjects having symptoms of SAHS.…”

Cross-hemispheric Alternating Current Stimulation During a Nap Disrupts Slow Wave Activity and Associated Memory Consolidation

“…This occurs across low delta (1.0–2.0 Hz), alpha (9.0–10.0 Hz) and spindle (13.0–14.0 Hz) ranges during NREM sleep [36], and predominates anteriorly – in the frontal brain region – during SWS [34]. Inter-hemispheric coherence in delta-range frequencies increases in humans in the transition from wakefulness to sleep [37], and inter-hemispheric EEG correlation in the delta-range has been reported to be higher in stage 2 and stage 4 sleep than in wakefulness [38]. Inter-hemispheric synchrony of EEG oscillations between homologous brain regions of cats were reported to be permanently disrupted when the corpus callosum was sectioned [39], suggesting that connectivity between hemispheres may be functionally relevant.…”

Patterns of Intrahemispheric EEG Asymmetry in Insomnia Sufferers: An Exploratory Study

“…Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO. In other words, we think that higher asymmetry during sleep (only in INS, not GS) may result in increases in objective-subjective discrepancy.…”

“…Our primary hypothesis, strictly limited to fronto-parietal derivations, is that INS will have higher fronto-parietal INTRA during sleep compared to GS, because frontal and parietal regions have been found to exhibit distinct patterns of INTER asymmetry in different subtypes of insomnia [28] and that many differences in EEG activity can be found in frontal derivations compared to GS [2][3][4][5][6][7]. Furthermore, we believe that the hypothesized increase in fronto-parietal asymmetry will occur especially during REM sleep, because other findings support the claim that INTRA asymmetry is accentuated in REM with respect to wakefulness [30], and that REM sleep is believed to be fragmented in INS [10]. Because discrepancies between sleep diaries' subjective ratings and PSG objective data are often reported in INS, including overestimation (subjective > objective) of their sleep onset latency (SOL) and wake after sleep onset (WASO) and underestimation (objective > subjective) of their total sleep time (TST) [28][29][30], we predict that intrahemispheric asymmetry measures that differ between groups (no hypothesis as to which regions) will be negatively correlated to TST and positively correlated to SOL and WASO.…”

Inter-hemispheric asynchrony of the brain during events of apnoea and EEG arousals

“…The effect was most intense and consistently seen in δ, α and β bands. It should be noted that other researchers (Barcaro et al 1986, Corsi-Cabrera et al 1996 have reported similar results considering the δ and β bands, for subjects drawn from a normal healthy population. This study extends their results by considering all four frequency bands; in addition, the present study includes clinically diagnosed SAHS patients as well as normal subjects having symptoms of SAHS.…”

Cross-hemispheric Alternating Current Stimulation During a Nap Disrupts Slow Wave Activity and Associated Memory Consolidation

“…This occurs across low delta (1.0–2.0 Hz), alpha (9.0–10.0 Hz) and spindle (13.0–14.0 Hz) ranges during NREM sleep [36], and predominates anteriorly – in the frontal brain region – during SWS [34]. Inter-hemispheric coherence in delta-range frequencies increases in humans in the transition from wakefulness to sleep [37], and inter-hemispheric EEG correlation in the delta-range has been reported to be higher in stage 2 and stage 4 sleep than in wakefulness [38]. Inter-hemispheric synchrony of EEG oscillations between homologous brain regions of cats were reported to be permanently disrupted when the corpus callosum was sectioned [39], suggesting that connectivity between hemispheres may be functionally relevant.…”