Limits...
Blindfolding during wakefulness causes decrease in sleep slow wave activity

View Article: PubMed Central - PubMed

ABSTRACT

Slow wave activity (SWA, 0.5–4 Hz) represents the predominant EEG oscillatory activity during slow wave sleep (SWS). Its amplitude is considered in part a reflection of synaptic potentiation in cortical networks due to encoding of information during prior waking, with higher amplitude indicating stronger potentiation. Previous studies showed that increasing and diminishing specific motor behaviors produced corresponding changes in SWA in the respective motor cortical areas during subsequent SWS. Here, we tested whether this relationship can be generalized to the visual system, that is, whether diminishing encoding of visual information likewise leads to a localized decrease in SWA over the visual cortex. Experiments were performed in healthy men whose eyes on two different days were or were not covered for 10.5 h before bedtime. The subject's EEG was recorded during sleep and, after sleep, visual evoked potentials (VEPs) were recorded. SWA during nonrapid eye movement sleep (NonREM sleep) was lower after blindfolding than after eyes open (P < 0.01). The decrease in SWA that was most consistent during the first 20 min of NonREM sleep, did not remain restricted to visual cortex regions, with changes over frontal and parietal cortical regions being even more pronounced. In the morning after sleep, the N75‐P100 peak‐to‐peak‐amplitude of the VEP was significantly diminished in the blindfolded condition. Our findings confirm a link between reduced wake encoding and diminished SWA during ensuing NonREM sleep, although this link appears not to be restricted to sensory cortical areas.

No MeSH data available.


Related in: MedlinePlus

Changes in SO density and SWA after blindfolding (n = 13). (A) Difference in SO density during the first 20‐min interval of NonREM sleep. Differences are indicated by statistical t‐values with negative values indicating lower density for the blindfolded than the eyes‐open condition. Significant differences at specific electrode locations are indicated by filled yellow circles (P < 0.01) and unfilled yellow circles (P < 0.05). (B) Time course of changes in SWA (0.5–4 Hz) and SO density during NonREM sleep of the first three 20‐min intervals and the remaining night. Means ± SEM from parieto‐occipital electrode sites (for illustrative purposes pooled across PO1, POz, PO2) are shown. tP < 0.1, **P < 0.01. SWA, Slow wave activity.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5392525&req=5

phy213239-fig-0002: Changes in SO density and SWA after blindfolding (n = 13). (A) Difference in SO density during the first 20‐min interval of NonREM sleep. Differences are indicated by statistical t‐values with negative values indicating lower density for the blindfolded than the eyes‐open condition. Significant differences at specific electrode locations are indicated by filled yellow circles (P < 0.01) and unfilled yellow circles (P < 0.05). (B) Time course of changes in SWA (0.5–4 Hz) and SO density during NonREM sleep of the first three 20‐min intervals and the remaining night. Means ± SEM from parieto‐occipital electrode sites (for illustrative purposes pooled across PO1, POz, PO2) are shown. tP < 0.1, **P < 0.01. SWA, Slow wave activity.

Mentions: Identification of discrete slow oscillations (SOs) corroborated results of the SWA analyses. SO density was strikingly lower after blindfolding than eyes‐open during the first 20 min of NonREM sleep (F(1,12) = 12.961; P = 0.004, Fig. 2A), and still tended to be lower in an ANOVA across the first 60 min of NonREM sleep (F(1,12) = 4.207; P = 0.063, for Blindfolding main effect, Fig. 2A). SO density after blindfolding was most consistently decreased over right fronto‐central areas (F(26,312) = 4.983; P = 0.007; for Blindfolding × Topography, Fig. 2B). There was no effect of blindfolding on any other of the SO parameters (including peak‐to‐peak amplitude, negative peak amplitude, and SO slope) or during later NonREM sleep periods of the night. Also, blindfolding did not induce any significant changes in slow (9–12 Hz) or fast (12–15 Hz) spindle activity (all P > 0.064).


Blindfolding during wakefulness causes decrease in sleep slow wave activity
Changes in SO density and SWA after blindfolding (n = 13). (A) Difference in SO density during the first 20‐min interval of NonREM sleep. Differences are indicated by statistical t‐values with negative values indicating lower density for the blindfolded than the eyes‐open condition. Significant differences at specific electrode locations are indicated by filled yellow circles (P < 0.01) and unfilled yellow circles (P < 0.05). (B) Time course of changes in SWA (0.5–4 Hz) and SO density during NonREM sleep of the first three 20‐min intervals and the remaining night. Means ± SEM from parieto‐occipital electrode sites (for illustrative purposes pooled across PO1, POz, PO2) are shown. tP < 0.1, **P < 0.01. SWA, Slow wave activity.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5392525&req=5

phy213239-fig-0002: Changes in SO density and SWA after blindfolding (n = 13). (A) Difference in SO density during the first 20‐min interval of NonREM sleep. Differences are indicated by statistical t‐values with negative values indicating lower density for the blindfolded than the eyes‐open condition. Significant differences at specific electrode locations are indicated by filled yellow circles (P < 0.01) and unfilled yellow circles (P < 0.05). (B) Time course of changes in SWA (0.5–4 Hz) and SO density during NonREM sleep of the first three 20‐min intervals and the remaining night. Means ± SEM from parieto‐occipital electrode sites (for illustrative purposes pooled across PO1, POz, PO2) are shown. tP < 0.1, **P < 0.01. SWA, Slow wave activity.
Mentions: Identification of discrete slow oscillations (SOs) corroborated results of the SWA analyses. SO density was strikingly lower after blindfolding than eyes‐open during the first 20 min of NonREM sleep (F(1,12) = 12.961; P = 0.004, Fig. 2A), and still tended to be lower in an ANOVA across the first 60 min of NonREM sleep (F(1,12) = 4.207; P = 0.063, for Blindfolding main effect, Fig. 2A). SO density after blindfolding was most consistently decreased over right fronto‐central areas (F(26,312) = 4.983; P = 0.007; for Blindfolding × Topography, Fig. 2B). There was no effect of blindfolding on any other of the SO parameters (including peak‐to‐peak amplitude, negative peak amplitude, and SO slope) or during later NonREM sleep periods of the night. Also, blindfolding did not induce any significant changes in slow (9–12 Hz) or fast (12–15 Hz) spindle activity (all P > 0.064).

View Article: PubMed Central - PubMed

ABSTRACT

Slow wave activity (SWA, 0.5&ndash;4&nbsp;Hz) represents the predominant EEG oscillatory activity during slow wave sleep (SWS). Its amplitude is considered in part a reflection of synaptic potentiation in cortical networks due to encoding of information during prior waking, with higher amplitude indicating stronger potentiation. Previous studies showed that increasing and diminishing specific motor behaviors produced corresponding changes in SWA in the respective motor cortical areas during subsequent SWS. Here, we tested whether this relationship can be generalized to the visual system, that is, whether diminishing encoding of visual information likewise leads to a localized decrease in SWA over the visual cortex. Experiments were performed in healthy men whose eyes on two different days were or were not covered for 10.5&nbsp;h before bedtime. The subject's EEG was recorded during sleep and, after sleep, visual evoked potentials (VEPs) were recorded. SWA during nonrapid eye movement sleep (NonREM sleep) was lower after blindfolding than after eyes open (P&nbsp;&lt;&nbsp;0.01). The decrease in SWA that was most consistent during the first 20&nbsp;min of NonREM sleep, did not remain restricted to visual cortex regions, with changes over frontal and parietal cortical regions being even more pronounced. In the morning after sleep, the N75&#8208;P100 peak&#8208;to&#8208;peak&#8208;amplitude of the VEP was significantly diminished in the blindfolded condition. Our findings confirm a link between reduced wake encoding and diminished SWA during ensuing NonREM sleep, although this link appears not to be restricted to sensory cortical areas.

No MeSH data available.


Related in: MedlinePlus