Plasticity changes in the brain in hypnosis and meditation

Contemporary Hypnosis

Volumn 26, Issue 4, 2009, Pages 194-215

  Halsband, Ulrike ^a   Mueller, Susanne ^a   Hinterberger, Thilo ^b   Strickner, Simon ^a  

^a UNIVERSITY OF FREIBURG   (Germany)

^b UNIVERSITY OF FREIBURG   (Germany)

Author keywords

Brain plasticity; EEG; FMRI; Hypnosis; Meditation; PET

Indexed keywords

EID: 74349092615     PISSN: 09605290     EISSN: None     Source Type: Journal    
DOI: 10.1002/ch.386     Document Type: Article

References (128)

1. Aftanas LI, Golocheikine SA (2001) Human anterior and frontal midline theta and lower alpha reflect emotionally positive state and internalized attention: high-resolution EEG investigation of meditation. Neuroscience Letters 310: 57-60.
2. Aftanas LI, Golocheikine SA (2002) Non-linear dynamic complexity of the human EEG during meditation. Neuroscience Letters 330: 143-6.
3. Aftanas LI, Golocheikine SA (2005) Impact of regular meditation practice on EEG activity at rest and during evoked negative emotions. International Journal of Neuroscience 115: 433-43.
4. Anand B, Chhina G, Singh B (1961) Some aspects of electroencephalographic studies in yogis. Electroencephalography and Clinical Neurophysiology 13: 452-6.
5. Bakan P, Svorad D, (1969) Resting EEG alpha and asymmetry of reflective lateral eye movements. Nature 223: 975-6.
6. Banquet JP (1972) EEG and meditation. Electroencephalography and Clinical Neurophysiology 33: 454.
7. Banquet JP (1973) Spectral analysis of the EEG in meditation. Electroencephalography and Clinical Neurophysiology 35: 143-51.
8. Barabasz AF (1983) EEG alpha-hypnotizability correlations are not simple covariates of subject self-selection. Biological Psychology 17: 169-72.
9. Baron Short E, Kose S, Mu Q, Borckardt J, Newberg A, George MS, Kozel FA (2007) Regional brain activation during meditation shows time and practice effects: an exploratory fMRI study. Evidence Based Complementary and Alternative Medicine. (Epub ahead of print).
10. Baschek IL, Bredenkamp J, Oehrle B, Wippich W (1977) Bestimmung der Bildhaftigkeit (I), Konkretheit (C) und der Bedeutungshaltigkeit (M) von 800 Substantiven. Zeitschrift für Experimentelle und Angewandte Psychologie 24: 353-96.
11. Benson H, Malhotra MS, Goldman RF, Jacobs GD, Hopkins PJ (1990) Three case reports of the metabolic and electroencephalographic changes during advanced Buddhist meditation techniques. Behavioral Medicine 16: 90-5.
12. Blakemore SJ, Oakley DA, Frith CD (2003) Delusions of alien control in the normal brain. Neuropsychologia 41: 1058-67.
13. Bongartz W (1985) Encoding of high-and low-imagery nouns during hypnotic age regression. Experimentelle Klinische Hypnose I: 143-51.
14. Cahn R, Polich J (2006) Meditation states and traits: EEG, ERP, and neuroimaging studies. Psychological Bulletin 132: 180-211.
15. Carrington P (1998) The Book of Meditation: The Complete Guide to Modern Meditation (rev ed) New York: Element Books.
16. Carter OL, Presti DE, Callistemon C, Ungerer Y, Liu GB, Pettigrew JD (2005) Meditation alters perceptual rivalry in tibetan buddhist monks. Current Biology 15: 412-13.
17. Corbetta M, Shulman GL (2002) Control of goal-directed and stimulus-driven attention in the brain. Nature Reviews Neuroscience 3: 201-15.
18. Corby JC, Roth WT, Zarcone VP jr, Kopell BS (1978) Psychophysiological correlates of the practice of tantric yoga meditation. Archives of General Psychiatry 35: 571-7.
19. Coromaldi E, Basar-Eroglu C, Stadler MA (2004) EEG-Rhythmen während tiefer Meditation: Eine Einzelfallstudie mit einem Zen-Meister. Hypnose und Kognition 21: 61-77.
20. Coull JT (1998) Neural correlates of attention and arousal: insights from electrophysiology, functional neuroimaging and psychopharmacology. Progress in Neurobiology 55: 343-61.
21. Craig AD (2000) How do you feel? Interoception: the sense of the physiological condition of the body. Nature Reviews Neuroscience 3: 655-66.
22. Crawford HJ (1990) Cognitive and psychophysiological correlates of hypnotic responsiveness and hypnosis. In: ML Fass, DP Brown (eds) Creative Mastery in Hypnosis and Hypnoanalysis. New York: Plenum, 47-54.
23. Crawford HJ, Allen SN (1996) Paired-associated learning and recall of high and low imagery words: moderating effects of hypnosis, hypnotic susceptibility level, and visualization abilities. American Journal of Psychology 109: 353-72.
24. Crawford HJ, Corby JC, Kopell BS (1996) Auditory event-related potentials while ignoring tone stimuli: attentional differences reflected in stimulus intensity and latency responses in low and highly hypnotizable persons. International Journal of Neuroscience 85: 57-69.
25. Crawford HJ, Knebel T, Kaplan L, Vendemia JM, Xie M, Jamison S, Pribram KH (1998) Hypnotic analgesia: 1. Somatosensory event-related potential changes to noxious stimuli and 2. Transfer learning to reduce chronic low back pain. International Journal of Clinical and Experimental Hypnosis 46: 92-132.
26. Crombie IK (1996) The Pocket Guide to Critical Appraisal. London: BMJ Publishing Group.
27. Damasio AR (2000) The Feeling of What Happens: Body and Emotion in the Making of Consciousness. San Diego: Harcourt Brace & Co.
28. De Pascalis V, Ray WJ, Tranquillo I, D'Amico D (1998) EEG activity and heart rate during recall of emotional events in hypnosis: relationships with hypnotizability and suggestibility. International Journal of Psychophysiology 29: 255-75.
29. Dietrich A (2003) Functional neuroanatomy of altered states of consciousness: thetransient hypofrontality hypothesis. Consciousness and Cognition 12: 231-56.
30. Doraiswami PM, Xiong CL (2007) Does meditation enhance cognition and brain longevity? Annals of the New York Academy of Science [Electronic Publication ahead of print].
31. Edmonston WE, Grotevant WR (1975) Hypnosis and alpha density. American Journal of Clinical Hypnosis 17: 221-32.
32. Egner T, Jamieson G, Gruzelier J (2005) Hypnosis decouples cognitive control from conflict monitoring processes of the frontal lobe. NeuroImage 27: 969-78.
33. Engstrom DR, London P, Hart JT (1970) Hypnotic susceptibility increased by EEG alpha training. Nature 227: 1261-2.
34. Faymonville ME, Boly M, Laureys S (2006) Functional neuroanatomy of the hypnotic state. Journal of Physiology (Paris) 99: 463-9.
35. Faymonville ME, Laureys S, Degueldre C, DelFiore G, Luxen A, Franck G, Lamy M, Maquet P (2000) Neural mechanisms of antinociceptive effects of hypnosis. Anesthesiology 92: 1257-67.
36. Faymonville ME, Mambourg PH, Joris J, Vrijens B, Fissette J, Albert A, Lamy M (1997)Psychological approaches during conscious sedation. Hypnosis versus stress reducingstrategies: a prospective randomized study. Pain 73: 361-7.
37. Fingelkurts AA, Fingelkurts AA, Kallio S, Revonsuo A (2007) Cortex functional connectivity as a neurophysiological correlate of hypnosis: an EEG case study. Neuropsychologia 45: 1452-62.
38. Glueck BC, Stroebel CF (1975) Biofeedback and meditation in the treatment of psychiatric illnesses. Comprehensive Psychiatry 16: 303-21.
39. Graffin NF, Ray WJ, Lundy R (1995) EEG concomitants of hypnosis and hypnotic susceptibility. Journal of Abnormal Psychology 104: 123-31.
40. Grant JA, Rainville P (2005) Hypnosis and meditation: similar experiential changes and shared brain mechanisms. Medical Hypotheses 65: 625-6.
41. Grond M, Pawlik G, Walter H, Lesch OM, Heiss W (1995) Hypnotic catalepsy-induced changes of regional cerebral glucose metabolism. Psychiatry Research: Neuroimaging 61: 173-9.
42. Gruzelier JH (2000) Redefining hypnosis: theory, methods and integration. Contemporary Hypnosis 17: 51-70.
43. Haggard P, Cartledge P, Meilyr D, Oakley DA (2004) Anomalous control: When 'free-will' is not conscious. Consciousness and Cognition 13: 646-54.
44. Halsband U (2004) Mechanismen des Lernens in Trance: funktionelle Bildgebung und Neuropsychologie. Hypnose und Kognition 21: 11-38.
45. Halsband U (2006) Learning in trance: functional brain imaging studies and neuropsychology. Journal of Physiology (Paris) 99 4-6: 470-82.
46. Halsband U (2008) Hypnose und Meditation: Was passiert in unserem Gehirn? Suggestionen 1: 6-24.
47. Halsband U (2009) Neurobiologie der Hypnose. In: D Revensdorf, B Peter (eds) Hypnose in Psychotherapie, Psychosomatik und Medizin. Heidelberg: Springer.
48. Halsband U, Herfort A (2007) Neurobiologische Grundlagen der medizinischen Hypnose. S. Schulz-Stübner (eds) Medizinische Hypnose, Schattauer, Chapter 2: 7-38.
49. Halsband U, Krause BJ, Schmidt D, Herzog H, Tellmann L, Müller-Gärtner HW (1998) Encoding and retrieval in declarative learning: a positron emission tomography study. Behavioural Brain Research 97: 69-78.
50. Halsband U, Krause BJ, Sipilä H, Teräs M, Laihinen A (2002) PET studies on the memory processing of word pairs in bilingual Finnish-English subjects. Behavioural Brain Research 132: 47-57.
51. Heap M, Aravind KK (2002) Hartland's Medical and Dental Hypnosis, 4th edn. Edinburgh: Churchill Livingston.
52. Herzog H, Lele VR, Kuwert T, Langen K-J, Kops ER, Feinendegen LE (1990) Changed pattern of regional glucose metabolism during yoga meditative relaxation. Neuropsychobiology 23: 182-7.
53. Hinterberger T, Halsband U (to be submitted) Hypnotic trance induction: an EEG study.
54. Hoelzel BK, Ott U, Hempel H, Hackl A, Wolf K, Stark R, Vaitl D (2007) Differential engagement of anterior cingulate and adjacent medial frontal cortex in adept meditators and non-meditators. Neuroscience Letters 421: 16-21.
55. Hoelzel BK, Ott U, Gard T, Hempel H, Weygandt M, Morgen K, Vaitl D (2008) Investigation of mindfulness meditation practitioners with voxel-based morphometry. Social Cognitive and Affective Neuroscience 3: 55-61.
56. Holroyd J (2003) The science of meditation and the state of hypnosis. American Journal of Clinical Hypnosis 46(2): 109-28.
57. Isotani T, Lehmann D, Pascual-Marqui RD, Kochi K, Wackermann J, Saito N, Yagyu T, Kinoshita T, Sasada K (2001) EEG source localization and global dimensional complexity in high- and low-hypnotizable subjects: a pilot study. Neuropsychobiology 44: 192-8.
58. Jamieson GA, Dwivedi P, Gruzelier JH (2005) Changes in mismatch negativity across prehypnosis, hypnosis and post-hypnosis conditions distinguish high from low hypnotic susceptibility groups. Brain Research Bulletin 67: 298-303.
59. Jevning R, Wallace RK, Beidebach M (1992) The physiology of meditation: a review. A wakeful hypometabolic integrated response. Neuroscience and Biobehavioral Reviews 16: 415-24.
60. Jha AP, Krompinger J, Baime MJ (2007) Mindfulness training modifies subsystems of attention. Cognitive Affective and Behavioral Neuroscience 7: 109-19.
61. Kastner S, Pinsk MA, De Weerd P, Desimone R, Ungerleider LG (1999) Increased activity in human visual cortex during directed attention in the absence of visual stimulation. Neuron 22: 751-61.
62. Katayama H, Gianotti LR, Isotani T, Faber PL, Sasada K, Kinoshita T, Lehmann D (2007) Classes of multichannel EEG microstates in light and deep hypnotic conditions. Brain Topography 20(1): 7-14.
63. Kesterson J (1989) Metabolic rate, respiratory exchange ratio and apneas during meditation. American Journal of Physiology R256: 632-8.
64. Kirsch I, Lynn SJ (1997) Hypnotic involuntariness and the automaticity of everyday life. American Journal of Clinical Hypnosis 40: 329-48.
65. Kjaer TW, Bertelsen C, Piccini P, Brooks D, Alving J, Lou HC (2002) Increased dopamine tone during meditation-induced change of consciousness. Brain Research and Cognition 13: 255-9.
66. Klein H and Myers M (1999) A set of principles for conducting and evaluating interpretive field studies in information systems. MIS Quarterly 23(1): 67-93.
67. Klimesch W (1999) EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis. Brain Research. Brain Research Reviews 29: 169-95.
68. Konradt B, Deeb S, Scholz OB (2005) Motor imagery in hypnosis: accuracy and duration of motor imagery in waking and hypnotic state. International Journal of Clinical and Experimental Hypnosis 53(2): 148-69.
69. Kosslyn SM, Thompson WL, Costantini-Ferrando MF, Alpert NM, Spiegel D (2000) Hypnotic visual illusion alters color processing in the brain. American Journal of Psychiatry 157(8): 1279-84.
70. Krause BJ, Horwitz B, Taylor JG, Schmidt D, Mottaghy FM, Herzog H, Halsband U, Müller-Gärtner H (1999a) Network analysis in episodic encoding and retrieval of word-pair associates: a PET study. European Journal of Neuroscience 11: 3293-301.
71. Krause BJ, Schmidt D, Mottaghy FM, Taylor J, Halsband U, Herzog H, Tellmann L, Müller-Gärtner HW (1999b) Episodic retrieval activates the precuneus irrespective of the imagery content of word pair associates. A PET study. Brain 122: 255-63.
72. Kubota Y, Sato W, Toichi M, Murai T, Okada T, Hayashi A, Sengoku A (2001) Frontal midline theta rhythm is correlated with cardiac autonomic activities during the performance of an attention demanding meditation procedure. Cognitive Brain Research 11: 281-7.
73. Laureys S (2005) The neural correlate of (un)awareness: lessons from the vegetative state. Trends in Cognitive Sciences 9: 556-9.
74. Laureys S, Maquet P, Faymonville ME (2004) Brain function druing hypnosis. In: A Otte, K Audenaert, K Peremans, K van Heeringen, RA Dierckx (eds) Nuclear Medicine in Psychiatry. Berlin: Springer-Verlag, 507-19.
75. Lazar SW, Bush G, Gollub RL, Fricchione GL, Khalsa G, Benson H (2000) Functional brain mapping of the relaxation response and meditation. Neuroreport 11: 1581-5.
76. Lazar SW, Kerr CE, Wasserman RH, Gray JR, Greve DN, Treadway MT, McGarvey M, Quinn BT, Dusek JA, Benson H, Rauch SL, Moore CI, Fischl B (2005) Meditation experience is associated with increased cortical thickness. Neuroreport 16: 1893-7.
77. Logothetis NK, Pauls J, Augath M, Trinath T, Oeltermann A (2001) Neurophysiological investigation of the basis of the fMRI signal. Nature 412: 150-7.
78. London P, Hart JT, Leibovitz MP (1968) EEG alpha rhythms and susceptibility to hypnosis. Nature 219: 71-2.
79. Lou HC, Kjaer TW, Friberg L, Wildschiodtz G, Holm S, Nowak M (1999) A 150-H20 PET study of meditation and the resting state of normal consciousness. Human Brain Mapping 7: 98-105.
80. Luders E, Toga AW, Lepore N, Glaser C (2009) The underlying and atomical correlates of long-term meditation: larger hippocampal and frontal volumes of gray matter. Neuroimage 45: 672-8.
81. Lundstrom BN, Petersson KM, Andersson J, Johansson M, Fransson P, Ingvar M (2003) Isolating the retrieval of imagined pictures during episodic memory: activation of the left precuneus and left prefrontal cortex. NeuroImage 20: 1934-43.
82. Lutz A, Dunne JD, Davidson RJ (2007) Meditation and the neuroscience of consciousness: an introduction. In: P Zelazo, M Moscovitch, E Thompson (eds) Cambridge Handbook of Consciousness. Cambridge: Cambridge University Press, 499-554.
83. Lutz A, Greischar LL, Rawlings NB, Ricard M, Davidson RJ (2004) Long-term meditators self-induce high-amplitude gamma synchrony during mental practice. Proceedings of the National Academy of Sciences USA 101: 16369-73.
84. Lutz A, Slagter HA, Dunne JD, Davidson RJ (2008) Attention regulation and monitoring in meditation. Trends in Cognitive Science 12: 163-9.
85. Maquet P, Faymonville ME, Degueldre C, Delfiore G, Franck G, Luxen A, Lamy M (1999) Functional neuroanatomy of hypnotic state. Biological Psychiatry 45: 327-33.
86. Meier H (1964) Deutsche Sprachstatistik. Hildesheim: Georg Ohms-Verlag.
87. Meng M, Tong F (2004) Can attention selectively bias bistable perception? Differences between binocular rivalry and ambiguous figures. Journal of Vision 4: 539-51.
88. Morgan AH, MacDonald H, Hilgard ER (1974) EEG alpha: lateral asymmetry related to task and hypnotizability. Psychophysiology 11: 275-82.
89. Mottaghy FM, Krause BJ, Schmidt D, Hautzel H, Herzog H, Shah NJ, Halsband U, Müller-Gärtner HW (2000) Comparison of PET and fMRI activation patterns during declarative memory processes. Nuklearmedizin 39: 196-203.
90. Mottaghy FM, Shah NJ, Krause BJ, Schmidt D, Halsband U, Jäncke L, Müller-Gärtner HW (1999) Neuronal correlates of encoding and retrieval in episodic memory during a paired word association learning task: a functional magnetic resonance imaging study. Experimental Brain Research 128: 332-42.
91. Mueller S, Halsband U (to be submitted) Cognitive and affective trait effects of intensive zen-meditaion training on brain and behaviour. An event-related longitudinal fMRI study.
92. Muzur A (2006) Hypnosis and modern frontal-lobe concepts - a sketch for a review and an invitation to one particularly promising field. Collegium Antropologicum 30: 205-211.
93. Newberg AB, Alavi A, Baime M, Pourdehnad M, Santanna J, d Àquili E (2001) The measurement of regional cerebral blood flow during the complex cognitive task of meditation. A preliminary SPECT study. Psychiatry Research 106: 113-22.
94. Newberg AB, Iversen J (2003) The neural basis of the complex mental task of meditation: neurotransmitter and neurochemical considerations. Medical Hypotheses 61: 282-91.
95. Oakley DA (1999) Hypnosis and conversion hysteria: a unifying model. Cognitive Neuropsychiatry 4: 243-65.
96. Otani A (2003) Eastern meditative techniques and hypnosis: a new synthesis. American Journal of Clinical Hypnosis 46: 97-108.
97. Otte A, Halsband U (2006) Brain imaging tools in neurosciences. Journal of Physiology (Paris) 99: 281-92.
98. Otto T (2007) Effective connectivity changes in hypnotic visual illusion. Master Thesis, University of Maastricht. A study carried out by Otto T, Halsband U, Goebel R.
99. Pan W, Zhang L, Xia Y (1994) The difference in EEG theta waves between concentrative and non-concentrative qigong states - a power spectrum and topographic mapping study. Journal of Traditional Chinese Medicine 14: 212-18.
100. Perlini AH, Spanos NP (1991) EEG alpha methodologies and hypnotizability: a critical review. Psychophysiology 28: 511-30.
101. Peter B (2009) Hypnose und die Konstruktion von Wirklichkeit. In: D Revensdorf, B Peter (eds) Hypnose in Psychotherapie, Psychosomatik und Medizin. Ein Manual für die Praxis. Heidelberg: Springer, 32-40.
102. Rainville P, Hofbauer RK, Bushnell MC, Duncan GH, Price DD (2002) Hypnosis modulates activity in brain structures involved in the regulation of consciousness. Journal of Cognitive Neuroscience 14: 887-901.
103. Rainville P, Hofbauer RK, Paus T, Duncan GH, Bushnell MC, Price DD (1999) Cerebral mechanisms of hypnotic induction and suggestion. Journal of Cognitive Neuroscience 11: 110-25.
104. Ray, Reginald A. (ed.) (2004) In the Presence of Masters: Wisdom from 30 Contemporary Tibetan Buddhist Teachers. Boston, Massachusetts: Shambhala.
105. Raz A, Fan J, Posner MI (2006) Neuroimaging and genetic associations of attentional and hypnotic processes. Journal of Physiology (Paris). 99(4-6): 483-91.
106. Raz A, Shapiro T (2002) Hypnosis and neuroscience: cross talk between clinical and cognitive research. Archives of General Psychiatry 59: 85-90.
107. Revenstorf D (1996) Klinische Hypnose - Gegenwärtiger Stand der Theorie und Empirie. Psychotherapie, Psychosomatik und Medizinische Psychologie 49: 5-13.
108. Roebroeck A, Formisano E, Goebel R (2005) Mapping directed influence over the brain using Granger causality and fMRI. NeuroImage 25: 230-42.
109. Sabourin ME, Cutcomb SD, Crawford HJ, Pribram K (1990) EEG correlates of hypnotic susceptibility and hypnotic trance: spectral analysis and coherence. International Journal of Psychophysiology 10: 125-42.
110. Schall U, Johnston P, Lagopoulos J, Juptner M, Jentzen W, Thienel R, Dittmann-Balcar A, Bender S, Ward PB (2003) Functional brain maps of Tower of London performance: positron emission tomography and functional magnetic resonance imaging study. NeuroImage 20: 1154-61.
111. Schmidt D, Krause BJ, Mottaghy FM, Halsband U, Herzog H, Tellmann L, Müller-Gärtner HW (2002) Brain systems engaged in encoding and retrieval of word-pair associates independent of their imagery content or presentation modalities. Neuropsychologia 40: 457-70.
112. Schmitter S, Diesch E, Amann M, Kroll A, Moayer M, Schad LR (2008) Silent echo-planar imaging for auditory fMRI. Magnetic Resonance Materials in Physics, Biology and Medicine 21: 317-25.
113. Schnyer DM, Allen JJ (1995) Attention-related electroencephalographic and event-related potential predictors of responsiveness to suggested posthypnotic amnesia. International Journal of Clinical and Experimental Hypnosis 43: 295-315.
114. Slagter HA, Lutz A, Greischar LL, Francis AD, Nieuwenhuis S, Davis JM and Davidson RJ (2007) Mental training affects distribution of limited brain resources. PLoS Biology 5, e138.
115. Spiegel D, Kosslyn SM (2004) Glauben ist Sehen: Die Neurophysiologie der Hypnose. Hypnose und Kognition 21(1-2): 119-37.
116. Srinivasan N, Baijal S, (2007) Concentrative meditation enhances preattentive processing: a mismatch negativity study. Neuroreport 18: 1709-12.
117. Sudsuang R, Chentanez V, Veluvan K (1991) Effects of buddhist meditation on serum cortisol and total protein levels, blood pressure, pulse rate, lung volume and reaction time. Physiology and Behavior 50: 543-8.
118. Szechtman H, Woody E, Bowers KS, Nahmias C (1998) Where the imaginal appears real: a positron emission tomography study. Proceedings of the National Academy of Sciences USA 95: 1956-60.
119. Tart CT (1972) States of consciousness and state-specific sciences. Science 176: 1203-10.
120. Tart CT (2000) Investigating altered states of consciousness on their own terms: a proposal for the creation of state-specific sciences. International Journal of Parapsychology 11(1): 7-41.
121. th Annual Convention of the American Psychological Association at San Francisco, August.
122. Tebecis AK, Provins KA, Farnbach RW, Pentony P (1975) Hypnosis and the EEG: a quantitative investigation. Journal of Nervous and Mental Disease 161: 1-17.
123. Tong F, Nakayama K, Vaughan JT, Kanwisher N (1998) Binocular rivalry and visual awareness in human extrastriate cortex. Neuron 21: 753-9.
124. Ulett GA, Akpinar S, Itil TM (1972) Hypnosis: physiological, pharmacological reality. American Journal of Psychiatry 128: 799-805.
125. Vestergaard-Poulsen P, van Beek M, Skewes J, Bjarkam CR, Stubberup M, Bertelsen J, Roepstorff A (2009) Long-term meditation is associated with increased gray matter density in the brain stem. Neuroreport 20: 170-4.
126. Wallace RK (1970) Physiological effects of transcendental meditation. Science 167: 1751-4.
127. Wallace RK, Benson H (1972) The physiology of meditation. Scientific American 226: 85-90.
128. nd edn. New York: Wiley.