Geschwind-Behan-Galaburda model

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The Geschwind-Behan-Galaburda model , also known as the GBG model , is a hypothesis on the lateralization of the brain .

The hypothesis

The American neurologist Norman Geschwind developed the hypothesis named after them in the 1980s together with his colleagues Peter Behan and Albert Galaburda . It says that during embryonic development, sex hormones , especially testosterone , influence the rate of brain maturation. From the 20th week of pregnancy, higher levels of testosterone would cause changes in the organization of the brain (lateralization), influence the development of the immune system and promote left-handedness . The left hemisphere of the brain reacts - so the hypothesis - in this development phase of the embryo more sensitively to disturbing factors such as testosterone, whereby the growth of individual areas in this hemisphere is inhibited. This inhibition, on the other hand, is supposed to cause compensatory growth in the right hemisphere, which results in an abnormal dominance of the right hemisphere. The increased testosterone level can be caused by the male fetus itself, the mother, by a male twin or by xenobiotics with hormonal properties.

According to the GBG hypothesis, the changes in the lateralization of the brain explain a number of phenomena. Right hemisphere skills such as music, math, and art are more pronounced in boys than girls. On the other hand, linguistic abnormalities - the language center is in the left brain hemisphere - such as dyslexia , hyperlexia and stuttering , are more common in boys than girls. In addition to the neurological effects of testosterone, this hormone is also said to have an influence on the embryonic development of the thymus , whereby the GBG hypothesis tries to explain influences on the development of the immune system and the consequences thereof. Taken as a whole, the Geschwind-Behan-Galaburda hypothesis is an explanatory model for a number of different phenomena. Men who per se have a higher testosterone level than women in their embryonic development phase should then:

  • be more often mathematically gifted
  • have increased learning disabilities
  • tend to be left-handed more often
  • have superior spatial skills
  • more likely to have language-related abnormalities
  • increasingly show a disturbed immune system.

Geschwind and Galaburda came up with their hypothesis after discovering an increased rate of immune diseases, migraines and learning disabilities in left-handed people and their families . In terms of immune diseases, their study found a ratio of 2.7 for left-handers compared to right-handers. In the case of speech disorders (dyslexia and stuttering), the ratio of left-handed to right-handed people was even higher.

reception

The Geschwind-Behan-Galaburda hypothesis has been very controversial since its formulation. Various epidemiological studies were able to confirm parts of the hypothesis in their statement. The hypothesis is very extensive and has a large number of parameters, so that a number of known phenomena can be explained with it, but on the other hand the hypothesis is therefore hardly falsifiable .

There are supporting epidemiological study findings for partial hypotheses of the GBG model. Left-handedness is significantly more common in men than in women. The same is true of stuttering and autism . Men, on the other hand, are on average superior to women in skills that primarily affect the right brain hemisphere, such as spatial thinking.

In the area of ​​immune disorders, a connection with left-handedness was found in allergies , asthma and ulcerative colitis . Left-handed women are also 65% more likely to develop multiple sclerosis . Similar statistical values ​​apply to left-handed men and women for breast cancer . On the other hand, there is a negative correlation with myasthenia gravis and arthritis , i.e. left-handed people are less likely to suffer from it than right-handed people.

Male cats are almost all left-handed while female cats are essentially right-handed. In chimpanzees , horses and dogs very similar study results were obtained.

Between 1939 and 1960, millions of pregnant women received injections of the synthetic nonsteroidal hormone diethylstilbestrol (DES) to prevent or reduce complications during pregnancy and stillbirths . A significantly higher rate of left-handers was born in the offspring of these women treated in this way.

further reading

  • G. Krommydas et al: Fetal sensitivity to testosterone, left-handedness and development of bronchial asthma: a new approach. In: Med Hypotheses 62, 2004, pp. 143-145. PMID 14729020
  • U. Tan and M. Tan: Testosterone and grasp-reflex differences in human neonates. In: Laterality 6, 2001, pp. 181–192. PMID 15513169
  • MM Clark et al .: Effects of perinatal testosterone on handedness of gerbils: support for part of the Geschwind-Galaburda hypothesis. In: Behav Neurosci 110, 1996, pp. 413-417. PMID 8731067
  • JW van Strien: Anomalous dominance is not a key concept in the Geschwind-Behan-Galaburda model. In: Brain Cogn 27, 1995, pp. 84-88. PMID 7748547
  • A. St-Marseille and CM Braun: Comments on immune aspects of the Geschwind-Behan-Galaburda model and of the article of Bryden, McManus, and Bulman-Fleming. In: Brain Cogn 26, 1994, pp. 281-290. PMID 7857622
  • JE Obrzut: The Geschwind-Behan-Galaburda theory of cerebral lateralization: thesis, antithesis, and synthesis? In: Brain Cogn 26, 1994, pp. 267-274. PMID 7857620
  • IC McManus and MP Bryden: Geschwind's theory of cerebral lateralization: developing a formal, causal model. In: Psychol Bull 110, 1991, pp. 237-253. PMID 1946868

Individual evidence

  1. ↑ a b N. Geschwind, P. Behan: Left-handedness: Association with Immune Disease, Migraine, and Developmental Learning Disorder. In: Proceedings of the National Academy of Sciences . Volume 79, Number 16, August 1982, pp. 5097-5100, PMID 6956919 , PMC 346835 (free full text).
  2. ↑ N. Geschwind and AM Galaburda: Cerebral lateralization, biological mechanisms, associations, and pathology: I. A hypothesis and a program for research. In: Archives of Neurology 42, 1985, pp. 428-459. PMID 3994562
  3. ↑ N. Geschwind and AM Galaburda: Cerebral lateralization, biological mechanisms, associations, and pathology: II. A hypothesis and a program for research. In: Archives of Neurology 42, 1985, pp. 521-552. PMID 3890812
  4. ↑ N. Geschwind and AM Galaburda: Cerebral lateralization, biological mechanisms, associations, and pathology: III. A hypothesis and a program for research. In: Archives of Neurology 42, 1985, pp. 634-654. PMID 3874617
  5. ^ A b c d F. Petermann et al.: Developmental science: developmental psychology, genetics, neuropsychology. Verlag Springer, 2004, ISBN 978-3-540-44299-8 , p. 140.
  6. ↑ SA Berenbaum and SD Denburg: Evaluating the empirical support for the role of testosterone in the Geschwind-Behan-Galaburda model of cerebral lateralization: commentary on Bryden, McManus, and Bulman-Fleming. In: Brain Cogn 27, 1995, pp. 79-83. PMID 7619133
  7. ↑ FH Previc: Assessing the legacy of the GBG model. In: Brain Cogn 26, 1994, pp. 174-180. PMID 7531984
  8. ^ BJ Kaplan and SG Crawford SG. The GBG model: is there more to consider than handedness? In: Brain Cogn 26, 1994, pp. 291-299. PMID 7857623
  9. ↑ FE Tønnessen: Testosterone and dyslexia. In: Pediatr Rehabil 1, 1997, pp. 51-57. PMID 9689239
  10. ^ IC McManus and MP Bryden: Geschwind's theory of cerebral lateralization: developing a formal, causal model. In: Psychol Bull 110, 1991, pp. 237-253. PMID 1946868 (Review)
  11. ↑ NS Morfit and NY Weekes; Handedness and immune function. In: Brain Cogn 46, 2001, pp. 209-213. PMID 11527332
  12. ^ N. Neave: Hormones and behavior: a psychological approach. Cambridge University Press, ISBN 978-052-169201-4 , p. 148.
  13. ^ S. Schmidt: Left-handedness - origin, evaluation, retraining. Grin-Verlag, 2001, ISBN 978-3-638-64475-4 , p. 14.
  14. ^ RE Weinstein among others: Allergy and the Geschwind-Behan-Galaburda Model. In: Brain Cogn 26, 1994, pp. 181-184. doi : 10.1006 / brcg.1994.1048
  15. ↑ G. Krommydas et al: Left-handedness in asthmatic children. In: Pediatr Allergy Immunol 14, 2003, pp. 234-237. PMID 12787305
  16. ^ H. Gardener et al .: The Relationship between Handedness and Risk of Multiple Sclerosis. In: Mult Scler 15, 2009, pp. 587-592. PMID 1938975
  17. ↑ MK Ramadhani, SG Elias, PA van Noord, DE Grobbee, PH Peeters, CS Uiterwaal: Innate left handedness and risk of breast cancer: case-cohort study. In: BMJ (Clinical research ed.). Volume 331, number 7521, October 2005, pp. 882-883, doi : 10.1136 / bmj.38572.440359.AE , PMID 16186135 , PMC 1255796 (free full text).
  18. ↑ L. Titus-Ernstoff include: Left-handedness in relation to breast cancer risk in postmenopausal women. In: Epidemiology 11, 2000, pp. 181-184. PMID 11021617
  19. ↑ L. Fritschi, M. Divitini, A. Talbot-Smith, M. Knuiman: Left-handedness and risk of breast cancer. In: British Journal of Cancer . Volume 97, Number 5, September 2007, pp. 686-687, doi : 10.1038 / sj.bjc.6603920 , PMID 17687338 , PMC 2360366 (free full text).
  20. ↑ Breast cancer - increased risk in left-handed women. In: Der Spiegel from September 26, 2005
  21. ↑ More breast cancer in left-handed women. In: scinexx of September 26, 2005
  22. ↑ Geschwind-Behan-Galaburda-Modell - Theory of left-handedness and lateralization. In: Andrologen.info September 2006, p. 108
  23. ↑ dnews.de: Almost all male cats are left-handed. ( Memento of December 12, 2009 in the Internet Archive ) of August 3, 2009
  24. ↑ DL Wells and S. Millsopp: lateralized behavior in the domestic cat, Felis silvestris catus. In: Animal Behavior 78, 2009, pp. 537-541. doi : 10.1016 / j.anbehav.2009.06.010
  25. ^ WD Hopkins and DA William: Hand use and gestural communication in chimpanzees (Pan troglodytes). In: Journal of Comparative Psychology 112, 1998, pp. 95-99. doi : 10.1037 / 0735-7036.112.1.95
  26. ^ J. Murphy et al .: Idiosyncratic motor laterality in the horse. In: Applied Animal Behavior Science 91, 2005, pp. 297-310. doi : 10.1016 / j.applanim 2004.11.001
  27. ^ DL Wells: Lateralised behavior in the domestic dog, Canis familiaris. In: Behavioral Processes 61, 2003, pp. 27-35. doi : 10.1016 / S0376-6357 (02) 00161-4
  28. ↑ L. Titus-Ernstoff et al.: Psychosexual characteristics of men and women exposed prenatally to diethylstilbestrol. In: Epidemiology 14, 2003, pp. 155-160. PMID 12606880
  29. ↑ JG Scheirs and AJ Vingerhoets: Handedness and other laterality indices in women prenatally exposed to DES. In: J Clin Exp Neuropsychol 17, 1995, pp. 725-730. PMID 8557813
  30. ↑ SC Schachter: Handedness in women with intrauterine exposure to diethylstilbestrol. In: Neuropsychologia 32, 1994 pp. 619-623. PMID 8084419
  31. ↑ JM Reinisch and SA Sanders: Effects of prenatal exposure to diethylstilbestrol (DES) on hemispheric laterality and spatial ability in human males. In: Horm Behav 26, 1992, pp. 62-75. PMID 1563729
  32. ↑ LL Smith and M. Hines: Language lateralization and handedness in women prenatally exposed to diethylstilbestrol (DES). In: Psychoneuroendocrinology 25, 2000, pp. 497-512. PMID 10818283