<s>
Beta	B-Algorithm
waves	I-Algorithm
,	O
or	O
beta	B-Algorithm
rhythm	I-Algorithm
,	O
are	O
a	O
neural	B-Algorithm
oscillation	I-Algorithm
(	O
brainwave	B-Algorithm
)	O
in	O
the	O
brain	O
with	O
a	O
frequency	O
range	O
of	O
between	O
12.5	O
and	O
30	O
Hz	O
(	O
12.5	O
to	O
30	O
cycles	O
per	O
second	O
)	O
.	O
</s>
<s>
Beta	B-Algorithm
waves	I-Algorithm
can	O
be	O
split	O
into	O
three	O
sections	O
:	O
Low	O
Beta	B-Algorithm
Waves	I-Algorithm
(	O
12.5	O
–	O
16Hz	O
,	O
"	O
Beta1	O
"	O
)	O
;	O
Beta	B-Algorithm
Waves	I-Algorithm
(	O
16.5	O
–	O
20Hz	O
,	O
"	O
Beta2	O
"	O
)	O
;	O
and	O
High	O
Beta	B-Algorithm
Waves	I-Algorithm
(	O
20.5	O
–	O
28Hz	O
,	O
"	O
Beta3	O
"	O
)	O
.	O
</s>
<s>
Beta	B-Algorithm
states	I-Algorithm
are	O
the	O
states	O
associated	O
with	O
normal	O
waking	O
consciousness	O
.	O
</s>
<s>
Beta	B-Algorithm
waves	I-Algorithm
were	O
discovered	O
and	O
named	O
by	O
the	O
German	O
psychiatrist	O
Hans	O
Berger	O
,	O
who	O
invented	O
electroencephalography	B-Application
(	O
EEG	B-Application
)	O
in	O
1924	O
,	O
as	O
a	O
method	O
of	O
recording	O
electrical	O
brain	B-Application
activity	I-Application
from	O
the	O
human	O
scalp	O
.	O
</s>
<s>
Berger	O
termed	O
the	O
larger	O
amplitude	O
,	O
slower	O
frequency	O
waves	O
that	O
appeared	O
over	O
the	O
posterior	O
scalp	O
when	O
the	O
subject	O
's	O
eye	O
were	O
closed	O
alpha	B-Application
waves	I-Application
.	O
</s>
<s>
The	O
smaller	O
amplitude	O
,	O
faster	O
frequency	O
waves	O
that	O
replaced	O
alpha	B-Application
waves	I-Application
when	O
the	O
subject	O
opened	O
their	O
eyes	O
were	O
then	O
termed	O
beta	B-Algorithm
waves	I-Algorithm
.	O
</s>
<s>
Low-amplitude	O
beta	B-Algorithm
waves	I-Algorithm
with	O
multiple	O
and	O
varying	O
frequencies	O
are	O
often	O
associated	O
with	O
active	O
,	O
busy	O
or	O
anxious	O
thinking	O
and	O
active	O
concentration	O
.	O
</s>
<s>
Over	O
the	O
motor	O
cortex	O
,	O
beta	B-Algorithm
waves	I-Algorithm
are	O
associated	O
with	O
the	O
muscle	O
contractions	O
that	O
happen	O
in	O
isotonic	O
movements	O
and	O
are	O
suppressed	O
prior	O
to	O
and	O
during	O
movement	O
changes	O
.	O
</s>
<s>
The	O
artificial	O
induction	O
of	O
increased	O
beta	B-Algorithm
waves	I-Algorithm
over	O
the	O
motor	O
cortex	O
by	O
a	O
form	O
of	O
electrical	O
stimulation	O
called	O
Transcranial	O
alternating-current	O
stimulation	O
consistent	O
with	O
its	O
link	O
to	O
isotonic	O
contraction	O
produces	O
a	O
slowing	O
of	O
motor	O
movements	O
.	O
</s>
<s>
Beta	B-Algorithm
waves	I-Algorithm
are	O
often	O
considered	O
indicative	O
of	O
inhibitory	O
cortical	O
transmission	O
mediated	O
by	O
gamma	O
aminobutyric	O
acid	O
(	O
GABA	O
)	O
,	O
the	O
principal	O
inhibitory	O
neurotransmitter	O
of	O
the	O
mammalian	O
nervous	O
system	O
.	O
</s>
<s>
Benzodiazepines	O
,	O
drugs	O
that	O
modulate	O
GABAA	O
receptors	O
,	O
induce	O
beta	B-Algorithm
waves	I-Algorithm
in	O
EEG	B-Application
recordings	O
from	O
humans	O
and	O
rats	O
.	O
</s>
<s>
Spontaneous	O
beta	B-Algorithm
waves	I-Algorithm
are	O
also	O
observed	O
diffusely	O
in	O
scalp	O
EEG	B-Application
recordings	O
from	O
children	O
with	O
duplication	O
15q11.2-q13.1	O
syndrome	O
(	O
Dup15q	O
)	O
who	O
have	O
duplications	O
of	O
GABAA	O
receptor	O
subunit	O
genes	O
GABRA5	O
,	O
GABRB3	O
,	O
and	O
GABRG3	O
.	O
</s>
<s>
Thus	O
,	O
beta	B-Algorithm
waves	I-Algorithm
are	O
likely	O
biomarkers	O
of	O
GABAergic	O
dysfunction	O
,	O
especially	O
in	O
neurodevelopmental	O
disorders	O
caused	O
by	O
15q	O
deletions/duplications	O
.	O
</s>
