| Reference code: | PT/FB/BL-2000-017.04 |
| Location: | Arquivo PCA - Pasta 6/2000
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Title:
| Dream recall, REMs and spectral EEG components in blind and sighted
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| Publication year: | 2002
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URL:
| http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2869.11.s1.7.x/pdf
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| Abstract/Results: | ABSTRACT:
OBJECTIVES:
To evaluate the EEG spectral content and rapid eye movements (REMs) associated with dream recall in sighted subjects and congenital blind.
METHODS:
10 congenital blind (CB) subjects (age: 28.2 ± 5.2; five males and five females) were studied and compared with a control sighted group(CS) (age: 28.2 ± 5.5; three males and five females). In all subjects medical or psychiatric diseases were excluded. During two consecutive nights polysomnographic recordings were performed at subjects home; both groups were subjected to periodic awakenings (period ¼ 90 min) and requested to dictate any dream recall to a voice activated tape recorder. For this study, only REM sleepawakenin gs were selected, whenever they were preceded by a stable REM epoch of at least 5 min duration. Power spectra were obtained for C4-A1 and O2-A1 EEG channels, by means of the Fast Fourier Transform and values from conventional EEG bands were selected; REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way anova and a posthoc Fisher test (for the features diagnosis (blind vs. sighted) and dream
recall (yes or no) as a function of time).
RESULTS:
REM awakenings were obtained in 10 CB and six CS subjects. The average of REM awakenings per subject and the recall ability were identical in both groups (REM awakenings: 1.6 for CB and 1.7 for CS; 60% of recall in both groups). CB had a lower REM density than CS (CB: 3.7 ± 3.4 vs. CS: 17. 4) ± 8.5; t ¼ )5.622; P < 0.0001); the same applied toREMbursts (P ¼ 0.0001) and isolated eye movements (P ¼ 0.0015). In the two-way anova, REM bursts and REM density were significantly different for positive dream recall (P ¼ 0.0125 and 0.0082, respectively), mainly for the CB group and for diagnosis (P ¼ 0.001 and 0.0002, respectively); furthermore for both features significant results were obtained for the interaction of time, recall and diagnosis (P ¼ 0.0139 and 0.0191, respectively); the interaction of recall and time was however, stronger (P ¼ 0.0089 and 0.0074). Spectral EEG bands: Higher delta power in O2 was associated with no dream recall (P ¼ 0.0279), whereas higher sigma was associated with the presence of dream recall both in C4 and O2 (P ¼ 0.0092 and 0.0012, respectively). Furthermore, in C4 the differences obtained concerned mainly the two diagnostic groups with CB having higher values of delta (P ¼ 0.0268), theta (P ¼ 0.0083) and sigma activity
(P ¼ 0.025) and CS higher values of alpha (P ¼ 0.0014) and beta activity (P ¼ 0.0072).
CONCLUSIONS:
In line with previous findings the data show that blind have lower REMs density. Both groups have also differences in the C4 spectral EEG components of REM preawakening epochs: CB showed an increase in the lower frequency bands (delta and theta) and in sigma activity (spindles) and CS have higher fast activities (alpha and beta). However the ability of dream recall in Congenital blind and Sighted controls is identical. In both groups dream recall is associated with an increase in REM bursts and density, higher sigma activity in C4 and O2 and lower delta activity in O2. REM bursts also show differences in the temporal profile. REM dream recall is associated with changes in EEG frequencies and increased REMs activity.
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| Accessibility: | Document does not exist in file
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Language:
| eng
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Author:
| Mestre, T.
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Secondary author(s):
| Bértolo, H., Paiva, T.
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Document type:
| Abstract
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Number of reproductions:
| 1
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Reference:
| Mestre, T., Bértolo, H., & Paiva, T. (2002). Dream recall, REMs and spectral EEG components in blind and sighted. Journal of Sleep Research, 11(Supplement s1), S153. https://doi.org/10.1046/j.1365-2869.11.s1.7.x
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| Indexed document: | Yes
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| Keywords: | Dream recall / Rapid eye movement (REM) / Electroencephalogram (EEG) / Frequency bands / Blind / Sighted
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Dream recall, REMs and spectral EEG components in blind and sighted |