<p></p><p>The early roots of EEG can be traced to two Italians, <b>Luigi Galvani </b>(1737-1798) and <b>Alesandro Volta</b> (1755-1832), and two Englishmen,&nbsp;<b>George Ohm </b>(1787-1832) and <b>Michael Farad</b>ay (1791-1867) (Collura, 1993, p. 476).&nbsp;Their discoveries have provided the understanding of electrical potential and current, and how it applies to muscular activity.&nbsp;<img src="@@PLUGINFILE@@/Volta%20and%20Galvani.png" alt="Volta and Galvani" width="420" height="243" role="presentation" class="atto_image_button_left"><br></p><p><img src="@@PLUGINFILE@@/Ohm%20and%20Faraday.png" alt="Ohm and Faraday" width="420" height="348" class="img-responsive atto_image_button_right"><br></p><p><br></p><p><br></p><p><br></p><p><br></p><p><b style="font-size: 1rem;"><br></b></p><p><b style="font-size: 1rem;"><br></b></p><p><b style="font-size: 1rem;">Richard Caton</b><span style="font-size: 1rem;"> (1842–1926) was the first electroencephalographer, as he was the first to record electrical activity from the exposed brains of rabbits and monkeys, using a mirrored galvanometer (Collura, 1993, p. 479).</span><br></p><p><img src="@@PLUGINFILE@@/Caton.png" alt="Caton" width="193" height="252" class="img-responsive atto_image_button_left"></p>In his 33rd year, Caton reported his
initial findings to the British Medical Association in 1875. In 1877 these were reported
more fully in a supplement to the British Medical Journal, and
again in 1887 to the Ninth International
Medical Congress in Washington DC.&nbsp;<p></p><p>In his experiments, Caton
placed unipolar electrodes on the surface of
both hemispheres of the exposed animals' brain, or one electrode on the exposed cerebral cortex and the other
on the surface of the skull. Currents were
measured via Thomson's galvanometer by optical magnification of the
meniscus.<img src="@@PLUGINFILE@@/Galvanometer.png" alt="Galvanometer" width="500" height="856" class="img-responsive atto_image_button_right"></p><p>Caton found that the currents of the brain increased with sleep.
These currents were vulnerable to anoxia and
anaesthesia, and they disappeared by the
animal’s death. Caton also found that strong
current variations occurred when light was
shone into the eyes. He also discovered
cerebral potential change evoked by sensory
stimulation. Caton did not recieve much notoriety in his lifetime for his experiments with brainwaves; in his obituary in the Lancet, Caton’s
contribution to electrophysiology was not mentioned (Haas, 2003).</p><p>EEG recordings were presented to the public at the same time as ECG
(electrocardiogram), but while the ECG, which was built by a man named
Einthoven, won the Nobel Peace Prize, the EEG remained unnoticed.&nbsp; In fact, none of the pioneers of EEG ever
received a similar honor, not even Caton. One of the reasons for this was the
initial and long-standing doubt that recording was actually showing brain
activity (Stam, 2006).<br></p><p></p><p>In 1924, German neurologist <b>Hans Berger </b>recorded the first<b>&nbsp;</b>EEG
on the brains of humans using a ballistic galvanometer (today, differential
amplifiers are used for this collection). The importance, for him, was based on
a parapsychological incident. His sister had a dream that he had fallen off a
horse and died, and wrote him a fearful letter about it. At the time of her
dream, he had, in fact, fallen off a horse and broken his leg. This synchronistic event encouraged
his belief that pursuing the EEG would uncover the mysteries of telepathy,
which he conceived was a phenomenon carried by the brain’s electrical activity
(Buzsaki, 2006, p. 4). He wanted to figure out the physiological basis for psychic phenomena. Additionally, he intended the EEG as a new technique for
psychiatric diagnosis and research (Ulrich, 2013, p. 1). He worked out of the University of Jena, in Germany, where he was the director of the psychiatric clinic
and a Professor of Neurology and
Psychiatry by 1919.<img src="@@PLUGINFILE@@/Berger.png" alt="Berger" width="448" height="454" class="img-responsive atto_image_button_left"></p>

<p>It was Berger coined "electroencephalogram" who first discovered a 10 Hz rhythm, which he dubbed
“alpha,” especially prominent when individuals closed their eyes. His second
EEG discovery was “beta,” which he found rarely co-existed with the alpha
rhythm (The delta rhythm was discovered in 1937 by <b>W.
Grey Walter</b>, who also later identified the theta wave in 1953).</p><p></p><p>Berger was excessively self-conscious about his initial findings
on EEG, so much so that he undertook five years of testing and surveying the
results of his studies on EEG before he released it to the public in report
form, in 1929 (during the years 1929-1938 he published 23 reports about his
studies of EEGs, and much of our modern knowledge of the subject, especially in
the middle frequencies, is due to his research).<a href="#_ftn1" name="_ftnref1" title=""><!--[if !supportFootnotes]-->[1]<!--[endif]--></a>Sadly,
when released his paper Über
das Elektrenkephalogramm des Menschen (On the
EEG in humans) in 1929,&nbsp;it was received with disbelief and derision from
the scientific community. He described normal and abnormal findings,&nbsp; associated with attention and mental effort, as well as cerebral injury. In 1934, Adrian and Matthews confirmed his basic observations in 1934, and thereafter&nbsp;EEG was accepted
and embraced with the advent of the first ink-writing oscillograph, called the
“neurograph,” by engineer J. F. Toennies.<a href="#_ftn2" name="_ftnref2" title=""><!--[if !supportFootnotes]-->[2]<!--[endif]--></a></p>

<p>After Berger’s, the first experiments of EEG
were conducted at the Bradley Hospital in Providence, Rhode Island in 1933 by
Herbert Jasper (Collura, 1993, p. 488). Berger’s findings were duplicated and
confirmed by Edgar Douglas Adrian (Lord Adrian), an English
electrophysiologist, which thrust EEG into scientific literature, and Jasper
pursued the development of an EEG lab in Montreal at the request of Wilder
Penfield, a neurosurgeon, who was the first to use EEG activity to localize
seizure activity using EEG. </p>

<p>In short
time, neurology adopted the EEG for psychiatric diagnostics and EEG became the
central tool for neurological electrodiagnosis, centering around epileptic
conditions. Even today, EEG is used primarily in clinical neurophysiology and
neurology. However, Berger wanted EEG to be used in “psychophysiology,” a term
coined by him to denote a new basic discipline of psychiatry.&nbsp;&nbsp;</p><div>

<p>Throughout
the 1930s and 1940s, EEG was explored at many medical institutes, including
Harvard Medical School, the University of Chicago, MIT, the Mayo Clinic, and
the University of Iowa.&nbsp; During World War
II, the EEG was used widely in neurological and psychological studies, and in
the 1940s and 1950s, many EEG instrument companies appeared in the United
States, Europe, and Japan (Collura, 1993). In 1958, Jasper lead a committee to
standardize the international 10/20 system that is used for electrodes today. This system is based on a set of latitudinal and
longitudinal arcs upon the surface of a spherical cranium. The positions of
electrodes are determined by measurements from standard landmarks (i.e.,
nasion, inion, and pre auricular points) on the skull. Electrodes are then
placed at locations 10%, 20%, 20%, 20%, 20%, and 10% along each of these arcs.</p>

<h3><img src="@@PLUGINFILE@@/10%20-%2020%20system.png" alt="10-20 system" width="333" height="320" class="img-responsive atto_image_button_left"></h3><p>In the 1960’s, Neal Miller and Leo DeCara carried out a series of
dramatic animal experiments, which demonstrated the possibility of operant
conditioning with a variety of internal autonomically regulated physiologic
processes, including: blood pressure, cardiac function, and intestinal
activity. Prior to their research, physiologists generally assumed that
organisms only had control over voluntary processes and not involuntary
processes. Their research provided the ground work for Barry Sterman’s sleep
research training the EEG, the Sensory Motor Rhythm (SMR), in cats.</p><br clear="all">

<hr align="left" size="1" width="33%">

<!--[endif]-->

<div id="ftn1">

<p><a href="#_ftnref1" name="_ftn1" title=""><!--[if !supportFootnotes]-->[1]<!--[endif]--></a>
Kaiser, David A. "Basic Principles of
Quantitative EEG." <i>Journal of Adult
Development</i>, Vol. 12, Nos. 2/3, August 2005</p>

</div>

<div id="ftn2">

<p><a href="#_ftnref2" name="_ftn2" title=""><!--[if !supportFootnotes]-->[2]<!--[endif]--></a>
An electroencephalograph is the instrument for recording,
Electroencephalography is the process of recording, and an electroencephalogram
<i>is</i> the recording, itself.</p></div></div><br><p></p><p></p>