睡眠是人類一天中不可或缺的活動，睡眠不只可消除疲勞，同時也進行身體及大腦功能修復。當我們睡著時，意識褪去，與外界刺激相連繫的大腦皮質漸漸不活化，雖然對外在刺激沒有反應，但腦部仍有活動，所以被認為這時期的腦部活動是自發性的 [1]，假如知道活動的區域，便可推測腦部在睡覺時的功能網絡。目前 fMRI 和 PET 兩者是主要用來取得功能性影像的儀器，但是MRI的噪音可能會干擾結果，而 PET 會使受試者受到輻射照射。因此，在非侵入性的腦造影上，MRI較常使用。而Loreta（low resolution brain electromagnetic tomography)可藉由EEG（electroencephalogram）的資料計算電流強度來推算神經活化的起源位置，因為腦部活化的地方就是神經元放電的地方，因此透過估計電流起源的分佈就是腦部活化區域的分佈 [2,3,4]。在這篇論文裡，我們試著要去找出睡眠中四個不同頻帶相對應的腦部活化區域 [5]，如果在不同的睡眠時期（即相對應的頻帶）這四個頻帶活化的位置在所有受試者都相同，我們便認為這些活化位置在睡眠時期中有空間上的一致性。實驗過程中一共有17位健康的受試者，皆為男性，平均年齡 23.82±4.46 歲。受試者帶著含有32個電極的EEG頭套，電極分佈範圍涵蓋整個腦部，採集 2 小時的睡眠 EEG 訊號後，由睡眠技師做睡眠分期，然後對每位受試者挑出波型較不受干擾的清醒期，第一期，第二期，第三期各 30 秒，之後用獨立成分分析法將腦電訊號分解，再選出我們有興趣的獨立成分用逆投影法重組回腦電圖。利用 Loreta 把篩選後的 EEG 訊號轉換成功能性影像，以顯示出活化的區域。我們測量活化區域中的最大電流值來當作指標，並用 t test 將 Brodmann 各區與全腦做比較找出顯著活化位置。從結果中發現 Brodmann Area 9（前額葉）在這四個頻帶都有活化；Brodmann Area 32（前扣帶迴）在 β、α、θ 頻帶有活化；BA6（額葉）在 α、θ、δ 頻帶裡有活化。若將每個頻帶的活化區域做大範圍的歸納，可發現β波在大腦中央與額葉有較密集的活化；α 波在額葉有較強與密集的活化；θ 波在額葉與顳葉有較密集的活化；δ 波則是在後半腦有明顯的活化。若將這幾個區域連起來，可得睡眠流程圖（dynamic sleep pathway）。另外也發現在δ頻帶中，BA6,9（前額葉）、BA 7（楔葉）、BA39（角葉）、BA40（雙側下頂葉）和BA30（後扣帶迴）同時有活化的現象，這幾個區域是固有網路連結所涵蓋的區域。這些結果顯示深睡時額葉仍在顯著活動，而固有網路連結與 δ 波較有關係。

1. C. J. Henderson, S. R. Butler, A. Glass. The localization of equivalent dipole of EEG sources by the application of electrical field theory. Electroenceph. Clin. Neurophysiol. Vol 39. 1975. 117-130
2. R.D. Pascual-Marqui, C.M. Michel, D. Lehmann. Low resolution electromagnetic tomography： a new method for localizing electrical activity in the brain. International Journal of Psychophysiology. Vol 18. 1994. 49-65
3. R.D. Pascual-Marqui, M. Esslen. K. Kochi, D. Lehmann. Functional imaging with low resolution brain electromagnetic tomography（LORETA）： review, new comparisons, and new validation. Japanese Journal of Clinical Neurophysiology. Vol 30. 2002. 81-94
4. T. T. Dang-Vu, M. Schabus, M. Desseilles et. al. Spontaneous neural activity during human slow wave sleep. PNAS. Vol.105. 2008, 15160-15165
5. E. M. Ventouras, P. Y. Ktonas, H. Tsekou et al. Independent component analysis for source localization of EEG sleep spindle component. Computational Intelligence and Neuroscience. Vol 2010. 2010.
6. T. J. Sejnowski, A. Destexhe. Why do we sleep? Brain Research. Vol 886. 2000. 208-223
7. S. K. DØrheim, G. T. Bondevik. M. Eberhard-Gran et al. Sleep and depression in postpartum women： a population- based study. Sleep. Vol 32. 2009. 847-855
8. R. Stickgold. Sleep-dependent memory consolidation. Nature. Vol 437. 2005. 1272-1278
9. T. Tsujimura, Y. Matsuo, T. Kevaki et al. Correlations of sleep disturbance with the immune system in type 2 diabetes mellitus. Diabetes Research and Clinical Practice. Vol 85.2009. 286-292
10. E. Verrillo, C. Bizzarri, M. Cappa et al. Sleep characteristics in children with growth hormone deficiency. Neuroendocrinology. Vol 94. 2011. 66-74
11. S.R. Patel. Reduced sleep as an obesity risk factor. Obesity Review. Vol 10. 2009. 61-68
12. B. M. Egan. Sleep and hypertension： burning the candle at both ends really is hazardous to your health. Hypertension. Vol 47. 2006. 816-817
13. R. Wolk, A. S. Gami, A. Garcia-Touchard et al. Sleep and cardiovascular disease. Curr Probl Cardiol. Vol 30. 2005. 625-662
14. O. D. Creutzfeld. Cortex Cerebri. Performance, structure and functional organization of the cortex. New York： Oxford University Press; 1955, p. 658
15. A. R. Wolfson, M. A. Carskadon. Understanding adolescents’ sleep patterns and school performance： a critical appraisal. Sleep Medicine Review. Vol 7. 2003. 491-506
16. S. Gais†, G. Albouy, M. Boly et al. Sleep transforms the cerebral trace of declarative memories. PNAS. Vol 104. 2007. 18778-18783
17. B. Rasch, C. Buchel, S. Gais et al, Odor cues during slow-wave sleep prompt declarative memory consolidation. Science. Vol 315. 2007. 1426-1429
18. M. J. de Leon , A. Convit, O. T. Wolf et. al. Prediction of cognitive decline in normal elderly subjects with 2-[¹⁸F]fluoro-2-deoxy-D-glucose/positron-emission tomography（FDG/PET）.PNAS. Vol 98. 2001. 10966-10971
19. S. Crottaz-Herbette, V. Menon. Where and When the Anterior Cingulate Cortex Modulates Attentional Response： Combined fMRI and ERP Evidence. Journal of Cognitive neuroscience. Vol 18. 2006. 776-780
20. E. Frei, A. Gamma, R. Pascula-Marqui et al. Localozation of MDMA-induced brain activity in healthy volunteers using low resolution brain electromagnetic tomography. Human Brain Mapping. Vol 14. 2001. 152-165
21. C Kaufmann, R. Wehrle, T.C. Wetter et al. Brain activation and hypothalamic functional connectivity during human non-rapid eye movement sleep： an EEG/fMRI study. Brain. Vol 29. 2005. 655-667
22. M. Ferrara, L. De Gennaro, G. Curcio et al. Regional difference of the temporal EEG dynamics during the first 30min of human sleep. Neurosci. Res. Vol 44. 2002. 83-9
23. S. Chen, T. J. Ross, W. Zhan et al. Group independent component analysis reveals consist resting-state networks across multiple sessions. Brain Research. Vol 1239. 2008. 141-151
24. D. Mantini, M.G. Perrucci, C. Del Gratta et al. Electrophysiological signatures of resting state networks in the human brain. PNAS. Vol 104. 2007. 13170-13175
25. R. R. Lninas. The intrinsic electrophysiological properties of mammalian neurons： Insights into central nervous system function. Science. Vol 242. 1988. 1654-1664
26. J. H. Lee, S. Oh, F. A. Jolesz et al. Application of Independent Component Analysis of the Data mining of Simultaneous EEG-fMRI： Preliminary Experience on Sleep Onset. Int J Neurosci. Vol 119（8）. 2009. 1118-1136
27. A. Rechtschaffen. Current perspectives on the function of sleep, Perspect Biol Med. Vol 41. 1998. 359-390
28. M. R. Ralph, M. Menaker. A mutation of the circadian system in golden hamster. Science. Vol 241. 1988. 1225-1227
29. Guyton, Arthur C. Human Physiology and Mechanisms of disease. W.B. Saunders Company. U.S.A. 1992- 5th ed. 453-456
30. 何敏夫. 臨床生理學. 合計圖書出版社. 台灣. 1999 第二版. 262
31. A. Rechtschaffen, A. Kales. A manual of standardized terminology, techniques and scoring system for sleep stages of human subjects. Washing DC： US Public Health Service, US Government Printing Offices; 1968
32. L. R. Silva, Y. Amitai, B. W. Connors. Intrinsic oscillation of neocortex generated by layer 5 pyramidal neurons. Science. Vol 251. 1991. 432-435
33. M. Brett, K. Christoff, R. Cusack et al. Using the Talairach Atlas with the MNI Template. Medical Research Council. 2004
34. J. Talairach and P. Tournoux. Co-Planar Stereotaxic Atlas of the Human Brain： 3-Dimentional Proportional System- An Approach to Cerebral Imaning , Thieme Medical Publisher. NY, USA. 1988
35. V. L. Towle, J. Bolaños, D. Suarez et al. The Spatial Location of EEG Electrodes： Locating the Best-Fitting Sphere Relative to Cortical Anatomy. Electorencephalogr Clin Neurophysiol. Vol 86. 1993. 1-6
36. B. J. Harrison, J. Pujol, M. Lopez-Sola et al. Consistency and functional specialization in the default mode brain network. PNAS. Vol 105. 2008. 9781-9786
37. L. J. Larson-Prior, J. M. Zempel, T. S. Nolan et al. Cortical network functional connectivity in the descent to sleep. PNAS . Vol 106. 2009. 4489-4494
38. M. Schabus, T. T. Dang-Vu, G. Albouy et al. Hemodynamic cerebral correlates of sleep spindles during human non-rapid eye movement sleep. PNAS. Vol 104. 2007. 13164-13169
39. D. J. Buysse, C. F. Reynolds III, T. H. Monk et al. Handbook of Psychiatric Measures, APA, Washington DC, 2000
40. P. J. Allen, O. Josephs, R. Turner. A method for removing imaging artifact from continuous EEG recorded during functional MRI. Neuroimage. Vol 12. 2000. 230–239
41. P. J. Allen, G. Polizzi, K. Krakow et al. Identification of EEG events in the MR scanner： the problem of pulse artifact and a method for its subtraction. Neuroimage . Vol 8. 1998. 229–239.
42. A.J. Bell, T.J. Sejnowski. An information-maximation approach to blind separation and blind deconvolution. Neural Computation. Vol 7. 1995. 1129-1159
43. J.F. Cardoso. Blind Signal Separation： Statistical Principle. Proceedings of the IEEE. Vol 86. 1998. 2009-2025
44. S. Makeig, A.J Bell, T.P.Jung et al. Blind separation of auditory event-related brain responses into independent component. Proc. Natl. Acad. Aci.USA. Vol 94. 1997. 10979-10984
45. Guyton, Arthur C. Human Physiology and Mechanisms of disease. W.B. Saunders Company. U.S.A. 1992- 5th ed. 439
46. H. Laufs, K. Krakow, P. Sterzer, et al. EEG signatures of attentional and cognitive default modes in spontaneous brain activity fluctuation at rest. PNAS. Vol 100. 2003： 11053-11058
47. R. T. Pivik, K. Harman. A re-conceptualization of EEG alpha activity as an index of arousal during sleep：all alpha is not equal. J. Sleep Research. Vol 4. 1995. 131-137
48. M. E. Raichle, A. M. MacLeod, A. Z. Snyder et al. A default mode of brain function. PNAS. Vol 98. 2001. 676-682
49. M. D. Greicius, V. Menon. Default-mode activity during a passive sensory task： Uncoupled from Deactivation but Impacting Activation. Journal of Cognitive Neuroscience. Vol 16. 2004. 1484-1492
50. G. Northoff, A. Heinzel, M. de Greck et al. Self-referential processing in our brain – a meta-analysis of imaging studies on the self. NeuroImage. Vol 31. 2006. 440-457
51. S. G.Horovitz, A. R. Braun, W. S. Carr et al. Decoupling of the brain’s default mode network during deep sleep. PNAS . Vol 106. 2009. 11376-11381