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Electroencephalography (EEG) – Brainwaves. Hans Berger (1873-1941) Trauma as a soldier threatened emotional connection between him and his sister, experienced.

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Presentation on theme: "Electroencephalography (EEG) – Brainwaves. Hans Berger (1873-1941) Trauma as a soldier threatened emotional connection between him and his sister, experienced."— Presentation transcript:

1 Electroencephalography (EEG) – Brainwaves

2 Hans Berger ( ) Trauma as a soldier threatened emotional connection between him and his sister, experienced as psychic transmission. Trauma as a soldier threatened emotional connection between him and his sister, experienced as psychic transmission. After the war he became a psychiatrist and worked on the technology until he obtained first recording in After the war he became a psychiatrist and worked on the technology until he obtained first recording in From 1929 to 1938 he published 14 scientific papers investigating EEG in clinical and normal populations. From 1929 to 1938 he published 14 scientific papers investigating EEG in clinical and normal populations.

3 Brain waves were first studied to help explain a psychic experience WWI German soldier WWI German soldier As a soldier in the German Army in first decade of 1900, Berger fell off his horse directly in front of artillery cart and was nearly run over As a soldier in the German Army in first decade of 1900, Berger fell off his horse directly in front of artillery cart and was nearly run over When he returned to HQ, telegram from his father saying his sister had feeling that he had been injured When he returned to HQ, telegram from his father saying his sister had feeling that he had been injured Berger would explore physical means of such psychic transmissions Berger would explore physical means of such psychic transmissions

4 Brain activity & psychic action He studied blood circulation in brain (1901). He investigated influence of heartbeat, respiration, vasomotor functions, and position of the head and body on brain pulsations measured through an opening (trephined) in the skull, but information was limited and ultimately disappointing. He studied blood circulation in brain (1901). He investigated influence of heartbeat, respiration, vasomotor functions, and position of the head and body on brain pulsations measured through an opening (trephined) in the skull, but information was limited and ultimately disappointing. In 1902 he measured electrical activity above skull defects with capillary electrometer; later a galvanometer. In 1902 he measured electrical activity above skull defects with capillary electrometer; later a galvanometer.

5 Previous Research leading to EEG Berger was fully aware that Richard Caton ( ), a Liverpool surgeon, had succeeded in 1875 in measuring electrical potentials on the exposed cortex of experimental animals (rabbit and monkey). Berger was fully aware that Richard Caton ( ), a Liverpool surgeon, had succeeded in 1875 in measuring electrical potentials on the exposed cortex of experimental animals (rabbit and monkey). Berger also knew of Polish physiologist Adolf Beck (1891) and Russian physiologist Pravdich- Neminski ( ) who recorded photographic record of the electrical activity of dogs brain through the skull. Berger also knew of Polish physiologist Adolf Beck (1891) and Russian physiologist Pravdich- Neminski ( ) who recorded photographic record of the electrical activity of dogs brain through the skull.

6 Secrecy 1926 lab 1926 lab Berger's experiments carried on in spare time and utter secrecy. Berger's experiments carried on in spare time and utter secrecy. As a diversionary measure he gave public discourses on telepathy, offering hypotheses of wave propagation to explain it. As a diversionary measure he gave public discourses on telepathy, offering hypotheses of wave propagation to explain it.

7 First EEG (1924) Berger made 73 EEG recordings from his 15y son, Klaus. Berger made 73 EEG recordings from his 15y son, Klaus. First frequency encountered was in 10-hertz range, (8 to 12 Hz) which he named alpha (others called the Berger rhythm).First frequency encountered was in 10-hertz range, (8 to 12 Hz) which he named alpha (others called the Berger rhythm). After 5 years of investigation, he published his findings. After 5 years of investigation, he published his findings. In 1929 he reported how brain waves changed dramatically if subject simply shifts from eyes closed to eyes open state. Furthermore, brain waves also changed when the subject sat quietly with eyes closed "focusing" on solving a math problem. In 1929 he reported how brain waves changed dramatically if subject simply shifts from eyes closed to eyes open state. Furthermore, brain waves also changed when the subject sat quietly with eyes closed "focusing" on solving a math problem.

8 Recognition came late He studied normal subjects and brain-injured, thereby laying the foundation for the application of the technique to clinical technology. In 1937 invited to preside with Adrian at symposium on electrical activity in the nervous system at the Congress of Psychology in Paris. They hailed Berger as the most distinguished of all the visitors. In 1937 invited to preside with Adrian at symposium on electrical activity in the nervous system at the Congress of Psychology in Paris. They hailed Berger as the most distinguished of all the visitors. He was ordered by Nazi authorities in 1938 to fire all Jewish employees at his lab. He was ordered by Nazi authorities in 1938 to fire all Jewish employees at his lab. He refused and was forced to retire. He hung himself at his clinic on June 1, 1941 He refused and was forced to retire. He hung himself at his clinic on June 1, 1941

9 Electrophysiology spontaneous activity, spontaneous activity, evoked potentials, and evoked potentials, and single neuron recordings single neuron recordings

10 MEG

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12 Instrument sensitivity 10 2 volts - Wall socket 10 2 volts - Wall socket volts - EKG volts - EKG (millivolts) (millivolts) volts – EEG volts – EEG (microvolts) (microvolts)

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14 10-20 System of Electrode Placement F = Frontal F = Frontal P = Parietal P = Parietal T = Temporal T = Temporal O = Occipital O = Occipital C = Central C = Central A = Auxiliary Odd # = Left Odd # = Left Even # = Right Even # = Right

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17 Acquisition

18 How do you study this?

19 … manipulate behavioral context, stimulus presentations

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21 Energy (Amplitude) & Speed (Frequency)

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23 Energy distribution by Frequency

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25 Clinical EEG Rhythms

26 Sleep Stages Sleep Stages

27 Inhibitory forces generate population rhythmicity

28 Alpha rhythm = idling rhythm, prepared to response, easier to recruit neurons in such states than if in active processing states

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30 Eyes Closed Baseline

31 Eyes Open Baseline

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33 Role of Topography and Timing

34 Posterior Alpha during Eyes Closed Rest : Normal

35 Frontal Slowing during Math: Abnormal

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37 Brain (surface) Maps Normal NormalAbnormal

38 AUTISM a neurodevelopmental disorder that impacts cognition and behavior a neurodevelopmental disorder that impacts cognition and behavior Auto –child is locked within him/herself Auto –child is locked within him/herself

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41 Sleep Spindle matures by 3 months of age

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43 1969 study where spindles in autistics ranged from Hz

44 Heartbreak of autism Lack of reciprocity, little connection with mother Lack of reciprocity, little connection with mother 1 in 10 chance of having another autistic child 1 in 10 chance of having another autistic child

45 4 times more likely for boys to be autistic than girls 4 times more likely for boys to be autistic than girls

46 Fully Matured Spindle in 4 month old infant at risk for autism

47 Perfectly Normal Boy


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