From the very beginning of EEG recordings authors have described the distinct
individuality of human brain wave patterns. Among the first authors who
investigated the phenomenon in a quantitative and systematic way were Travis
and Gottlober who published as early as 1936 and 1937 two articles entitled
"Do brain-waves have individuality?" and "How consistent are and individual's
brain potentials from day to day?". At the same time (1936) Davis and Davis
published the first twin study, stating that the within-pair differences of
the resting EEG derived from monozygotic twins were not greater than the
fluctuations within a subject over time.
To address these questions we performed a normative study with 138 healthy
volunteers (75 males and 63 females with ages between 20 and 35 years) who had
been selected by means of a specifically developed "health" questionnaire comprising
65 somatic, psychiatric and social items. The EEGs of these persons were recorded
twice at an interval of 14 days and at a fixed time between 8 and 10 o'clock in
the morning, thus excluding variations due to circadiane rhythms. All EEGs were
recorded under comparable experimental conditions (bipolar leads: P3-O1, P4-O2,
T3-T5, T4-T6, T5-O1, T6-O2). Using these data we performed systematic
inter-individual comparisons (all possible pairings) and compared the resulting
distribution of EEG similarities with the distribution of within-subject EEG
similarities derived from comparisons between the recordings at 14-day intervals
(Figure). The data enabled a computerized identification of persons at a sensitivity
and specificity of >90%.
To address the question of longterm stability of individual EEG characteristics
we have carried out a 5-year follow-up of 30 subjects (15 males, 15 females, ages
25-40 years) using the same experimental design as before. The indeed remarkable
stability of individual EEG characteristics over time (cf. 4 subjects shown on web
page "long-term stability") enabled a computerized identification of persons at a
similar rate as for 14-day intervals: 26 subjects (86.7% with a perfect one-to-one
mapping between first recording and second recording 5 years later, 2 individuals
(6.7%) whose patterns corresponded to the correct one plus at least one additional
pattern, and 5 individuals (6.7%) whose patterns did not correctly correspond,
though well above the average between-subject value.
Stassen HH, Bachmann S, Bridler R, Cattapan K, Herzig D, Schneeberger A, Seifritz E. Inflammatory
Processes linked to Major Depression and Schizophrenic Disorders and the Effects of Polypharmacy
in Psychiatry: Evidence from a longitudinal Study of 279 Patients under Therapy. Eur Arch
Psychiatry Clin Neurosci. 2021; 271(3): 507-520
[
get the article]
Braun S, Bridler R, Müller N, Schwarz MJ, Seifritz E, Weisbrod M, Zgraggen A, Stassen HH:
Inflammatory Processes and Schizophrenia: Two Independent Lines of Evidence from a Study
of Twins Discordant and Concordant for Schizophrenic Disorders. Eur Arch Psychiatry Clin
Neurosci 2017; 267: 377-389
[
get the article]
Braun S, Bridler R, Müller N, Schwarz MJ, Seifritz E, Weisbrod M, Zgraggen A, Stassen HH:
Inflammatory Processes and Schizophrenia: Two Independent Lines of Evidence From a Study
of Twins Discordant and Concordant for Schizophrenic Disorders. Neuropsychopharmacology
2016; 41: S414–S415
Stassen HH, Delfino JP, Kluckner VJ, Lott P, Mohr C: Vulnerabilität und psychische Erkrankung.
Swiss Archives of Neurology and Psychiatry 2014; 165(5): 152-157
Stassen HH, Angst J, Hell D, Scharfetter C, Szegedi A: Is there a common resilience mechanism
underlying antidepressant drug response? Evidence from 2'848 patients. J Clin Psychiatry 2007;
68(8): 1195-1205
Buckelmüller J, Landolt HP, Stassen HH, Achermann P: Trait-like individual differences in the
human sleep EEG. Neuroscience 2006; 138: 351-356
Weisbrod M, Hill H, Sauer H, Niethammer R, Guggenbühl S, Stassen HH: Nongenetic pathologic
developments of brain-wave patterns in monozygotic twins discordant and concordant for
schizophrenia. Am J Med Genetics B 2004; 125: 1-9
Stassen HH: EEG and evoked potentials. In: D. Cooper (ed) Nature Encyclopedia of the Human
Genome. Nature Publishing Group, London 2003; 3: 266-269
Umbricht D, Koller R, Schmid L, Skrabo A, Grübel C, Huber T, Stassen HH: How specific are
deficits in mismatch negativity generation to schizophrenia? Biol Psychiatry 2003; 53:
1120-1131
Dünki RM, Schmid GB, Stassen HH: Intraindividual specificity and stability of the human EEG:
Linear vs. nonlinear approaches. Meth Inform Med 2000; 39: 78-82
Stassen HH, Coppola R. Torrey EF, Gottesman II, Kuny S, Rickler KC, Hell D: EEG differences in
monozygotic twins discordant and concordant for schizophrenia. Psychophysiology 1999; 36,1:
109-117
Stassen HH, Bomben G, Hell D: Familial brain wave patterns: study of a 12 sib family. Psychiat
Genetics 1998; 8: 141-153
Dünki RM, Schmid GB, Scheidegger P, Stassen HH, Bomben G, Propping P: Reliable computer-assisted
classification of the EEG: EEG variants in index cases and their first-degree relatives.
Am J Med Genetics B 1996; 67,1: 1-8
Kaprio J, Buchsbaum M, Gottesman II, Heath A, Körner J, Kringlen E, McGuffin P, Propping P,
Rietschel M, Stassen HH: What can twin studies contribute to the understanding of adult
psychopathology? In: T.J. Bouchard jr. and P. Propping: Twins as a tool for behavioral
genetics. Chichester: John Wiley & Sons, Dahlem Workshop Reports, Life Sciences Research
Report 1993; 53: 287-299
Stassen HH, Lykken DT, Propping P: Zwillingsuntersuchungen zur Genetik des normalen
Elektroenzephalogramms. In: P. Baumann (ed): Biologische Psychiatrie der Gegenwart, Wien:
Springer 1993, 139-144
Stassen HH, Lykken DT, Propping P, Bomben G: Genetic determination of the human EEG (survey
of recent results from twins reared together and apart). Human Genetics 1988; 80:
165-176
Stassen HH, Lykken DT, Bomben G: The within-pair similarity of twins reared apart. Eur Arch
Psychiatr Neurol Sci 1988; 237: 244-252
Stassen HH, Bomben G, Propping P: Genetic aspects of the EEG: an investigation into the
within-pair similarity of monozygotic and dizygotic twins with a new method of analysis.
Electroenceph clin Neurophysiol 1987; 66: 489-501
Stassen HH: The similarity approach to EEG analysis. Meth Inform Med 1985; 24: 200-212
Stassen HH: Computerized recognition of persons by EEG spectral patterns. Electroenceph
clin Neurophysiol 1980; 49: 190-194