<s>
Delta	B-Algorithm
waves	I-Algorithm
are	O
high	O
amplitude	B-Application
neural	B-Algorithm
oscillations	I-Algorithm
with	O
a	O
frequency	O
between	O
0.5	O
and	O
4	O
hertz	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
,	O
like	O
other	O
brain	B-Algorithm
waves	I-Algorithm
,	O
can	O
be	O
recorded	O
with	O
electroencephalography	B-Application
(	O
EEG	B-Application
)	O
and	O
are	O
usually	O
associated	O
with	O
the	O
deep	O
stage	O
3	O
of	O
NREM	O
sleep	O
,	O
also	O
known	O
as	O
slow-wave	O
sleep	O
(	O
SWS	O
)	O
,	O
and	O
aid	O
in	O
characterizing	O
the	O
depth	O
of	O
sleep	O
.	O
</s>
<s>
Suppression	O
of	O
delta	B-Algorithm
waves	I-Algorithm
leads	O
to	O
inability	O
of	O
body	O
rejuvenation	O
,	O
brain	O
revitalization	O
and	O
poor	O
sleep	O
.	O
</s>
<s>
"	O
Delta	B-Algorithm
waves	I-Algorithm
"	O
were	O
first	O
described	O
in	O
the	O
1930s	O
by	O
W	O
.	O
Grey	O
Walter	O
,	O
who	O
improved	O
upon	O
Hans	O
Berger	O
's	O
electroencephalograph	B-Application
machine	O
(	O
EEG	B-Application
)	O
to	O
detect	O
alpha	O
and	O
delta	B-Algorithm
waves	I-Algorithm
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
can	O
be	O
quantified	O
using	O
quantitative	B-Algorithm
electroencephalography	I-Algorithm
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
,	O
like	O
all	O
brain	B-Algorithm
waves	I-Algorithm
,	O
can	O
be	O
detected	O
by	O
electroencephalography	B-Application
(	O
EEG	B-Application
)	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
were	O
originally	O
defined	O
as	O
having	O
a	O
frequency	O
between	O
1	O
and	O
4	O
Hz	O
,	O
although	O
more	O
recent	O
classifications	O
put	O
the	O
boundaries	O
at	O
between	O
0.5	O
and	O
2Hz	O
.	O
</s>
<s>
They	O
are	O
the	O
slowest	O
and	O
highest	O
amplitude	B-Application
classically	O
described	O
brainwaves	B-Algorithm
,	O
although	O
recent	O
studies	O
have	O
described	O
slower	O
(	O
<	O
0.1Hz	O
)	O
oscillations	O
Delta	B-Algorithm
waves	I-Algorithm
begin	O
to	O
appear	O
in	O
stage	O
3	O
sleep	O
,	O
but	O
by	O
stage	O
4	O
nearly	O
all	O
spectral	O
activity	O
is	O
dominated	O
by	O
delta	B-Algorithm
waves	I-Algorithm
.	O
</s>
<s>
Stage	O
3	O
sleep	O
is	O
defined	O
as	O
having	O
less	O
than	O
50%	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
,	O
while	O
stage	O
4	O
sleep	O
has	O
more	O
than	O
50%	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
.	O
</s>
<s>
During	O
N3	O
SWS	O
,	O
delta	B-Algorithm
waves	I-Algorithm
account	O
for	O
20%	O
or	O
more	O
of	O
the	O
EEG	B-Application
record	O
during	O
this	O
stage	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
occur	O
in	O
all	O
mammals	O
,	O
and	O
potentially	O
all	O
animals	O
as	O
well	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
are	O
often	O
associated	O
with	O
another	O
EEG	B-Application
phenomenon	O
,	O
the	O
K-complex	B-Algorithm
.	O
</s>
<s>
K-Complexes	B-Algorithm
have	O
been	O
shown	O
to	O
immediately	O
precede	O
delta	B-Algorithm
waves	I-Algorithm
in	O
slow	O
wave	O
sleep	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
have	O
also	O
been	O
classified	O
according	O
to	O
the	O
location	O
of	O
the	O
activity	O
into	O
frontal	O
(	O
FIRDA	O
)	O
,	O
temporal	O
(	O
TIRDA	O
)	O
,	O
and	O
occipital	O
(	O
OIRDA	O
)	O
intermittent	O
delta	B-Algorithm
activity	I-Algorithm
.	O
</s>
<s>
Females	O
have	O
been	O
shown	O
to	O
have	O
more	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
,	O
and	O
this	O
is	O
true	O
across	O
most	O
mammal	O
species	O
.	O
</s>
<s>
This	O
discrepancy	O
does	O
not	O
become	O
apparent	O
until	O
early	O
adulthood	O
(	O
in	O
the	O
30s	O
or	O
40s	O
in	O
humans	O
)	O
,	O
with	O
males	O
showing	O
greater	O
age-related	O
reductions	O
in	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
than	O
females	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
can	O
arise	O
either	O
in	O
the	O
thalamus	O
or	O
in	O
the	O
cortex	O
.	O
</s>
<s>
In	O
the	O
cortex	O
,	O
the	O
suprachiasmatic	O
nuclei	O
have	O
been	O
shown	O
to	O
regulate	O
delta	B-Algorithm
waves	I-Algorithm
,	O
as	O
lesions	O
to	O
this	O
area	O
have	O
been	O
shown	O
to	O
cause	O
disruptions	O
in	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
.	O
</s>
<s>
In	O
addition	O
,	O
delta	B-Algorithm
waves	I-Algorithm
show	O
a	O
lateralization	O
,	O
with	O
right	O
hemisphere	O
dominance	O
during	O
sleep	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
have	O
been	O
shown	O
to	O
be	O
mediated	O
in	O
part	O
by	O
T-type	O
calcium	O
channels	O
.	O
</s>
<s>
During	O
delta	B-Algorithm
wave	I-Algorithm
sleep	O
,	O
neurons	O
are	O
globally	O
inhibited	O
by	O
gamma-aminobutyric	O
acid	O
(	O
GABA	O
)	O
.	O
</s>
<s>
Delta	B-Algorithm
activity	I-Algorithm
stimulates	O
the	O
release	O
of	O
several	O
hormones	O
,	O
including	O
growth	O
hormone	O
releasing	O
hormone	O
GHRH	O
and	O
prolactin	O
(	O
PRL	O
)	O
.	O
</s>
<s>
Infants	O
have	O
been	O
shown	O
to	O
spend	O
a	O
great	O
deal	O
of	O
time	O
in	O
slow-wave	O
sleep	O
,	O
and	O
thus	O
have	O
more	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
.	O
</s>
<s>
Analysis	O
of	O
the	O
waking	O
EEG	B-Application
of	O
a	O
newborn	O
infant	O
indicates	O
that	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
is	O
predominant	O
in	O
that	O
age	O
,	O
and	O
still	O
appears	O
in	O
a	O
waking	O
EEG	B-Application
of	O
five-year-olds	O
.	O
</s>
<s>
Delta	B-Algorithm
wave	I-Algorithm
activity	O
during	O
slow-wave	O
sleep	O
declines	O
during	O
adolescence	O
,	O
with	O
a	O
drop	O
of	O
around	O
25%	O
reported	O
between	O
the	O
ages	O
of	O
11	O
and	O
14	O
years	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
have	O
been	O
shown	O
to	O
decrease	O
across	O
the	O
lifespan	O
,	O
with	O
most	O
of	O
the	O
decline	O
seen	O
in	O
the	O
mid-forties	O
.	O
</s>
<s>
By	O
the	O
age	O
of	O
about	O
75	O
,	O
stage	O
four	O
sleep	O
and	O
delta	B-Algorithm
waves	I-Algorithm
may	O
be	O
entirely	O
absent	O
.	O
</s>
<s>
In	O
addition	O
to	O
a	O
decrease	O
in	O
the	O
incidence	O
of	O
delta	B-Algorithm
waves	I-Algorithm
during	O
slow-wave	O
sleep	O
in	O
the	O
elderly	O
,	O
the	O
incidence	O
of	O
temporal	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
is	O
commonly	O
seen	O
in	O
older	O
adults	O
,	O
and	O
incidences	O
also	O
increase	O
with	O
age	O
.	O
</s>
<s>
Regional	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
not	O
associated	O
with	O
NREM	O
sleep	O
was	O
first	O
described	O
by	O
W	O
.	O
Grey	O
Walter	O
,	O
who	O
studied	O
cerebral	O
hemisphere	O
tumors	O
.	O
</s>
<s>
Disruptions	O
in	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
and	O
slow	O
wave	O
sleep	O
are	O
seen	O
in	O
a	O
wide	O
array	O
of	O
disorders	O
.	O
</s>
<s>
In	O
some	O
cases	O
there	O
may	O
be	O
increases	O
or	O
decreases	O
in	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
,	O
while	O
others	O
may	O
manifest	O
as	O
disruptions	O
in	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
,	O
such	O
as	O
alpha	O
waves	O
presenting	O
in	O
the	O
EEG	B-Application
spectrum	O
.	O
</s>
<s>
Delta	B-Algorithm
wave	I-Algorithm
disruptions	O
may	O
present	O
as	O
a	O
result	O
of	O
physiological	O
damage	O
,	O
changes	O
in	O
nutrient	O
metabolism	O
,	O
chemical	O
alteration	O
,	O
or	O
may	O
also	O
be	O
idiopathic	O
.	O
</s>
<s>
Disruptions	O
in	O
delta	B-Algorithm
activity	I-Algorithm
is	O
seen	O
in	O
adults	O
during	O
states	O
of	O
intoxication	O
or	O
delirium	O
and	O
in	O
those	O
diagnosed	O
with	O
various	O
neurological	O
disorders	O
such	O
as	O
dementia	O
or	O
schizophrenia	B-Application
.	O
</s>
<s>
Temporal	O
low-voltage	O
irregular	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
has	O
been	O
commonly	O
detected	O
in	O
patients	O
with	O
ischemic	O
brain	O
diseases	O
,	O
particularly	O
in	O
association	O
with	O
small	O
ischemic	O
lesions	O
and	O
is	O
seen	O
to	O
be	O
indicative	O
of	O
early-stage	O
cerebrovascular	O
damage	O
.	O
</s>
<s>
Sleep	O
walking	O
and	O
sleep	O
talking	O
most	O
often	O
occur	O
during	O
periods	O
of	O
high	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
.	O
</s>
<s>
Sleep	O
walkers	O
have	O
also	O
been	O
shown	O
to	O
have	O
more	O
hypersynchronous	O
delta	B-Algorithm
activity	I-Algorithm
(	O
HSD	O
)	O
compared	O
to	O
total	O
time	O
spent	O
in	O
stages	O
2	O
,	O
3	O
,	O
and	O
4	O
sleep	O
relative	O
to	O
healthy	O
controls	O
.	O
</s>
<s>
HSD	O
refers	O
to	O
the	O
presence	O
of	O
continuous	O
,	O
high-voltage	O
(	O
>	O
150	O
µV	O
)	O
delta	B-Algorithm
waves	I-Algorithm
seen	O
in	O
sleep	O
EEGs	B-Application
.	O
</s>
<s>
Total	O
sleep	O
deprivation	O
has	O
been	O
shown	O
to	O
increase	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
during	O
sleep	O
recovery	O
,	O
and	O
has	O
also	O
been	O
shown	O
to	O
increase	O
hypersynchronous	O
delta	B-Algorithm
activity	I-Algorithm
.	O
</s>
<s>
Sleep	O
disturbances	O
,	O
as	O
well	O
as	O
dementia	O
,	O
are	O
common	O
features	O
of	O
Parkinson	O
's	O
disease	O
,	O
and	O
patients	O
with	O
this	O
disease	O
show	O
disrupted	O
brain	B-Algorithm
wave	I-Algorithm
activity	O
.	O
</s>
<s>
People	O
with	O
schizophrenia	B-Application
have	O
shown	O
disrupted	O
EEG	B-Application
patterns	O
,	O
and	O
there	O
is	O
a	O
close	O
association	O
of	O
reduced	O
delta	B-Algorithm
waves	I-Algorithm
during	O
deep	B-Application
sleep	I-Application
and	O
negative	O
symptoms	O
associated	O
with	O
schizophrenia	B-Application
.	O
</s>
<s>
During	O
slow	O
wave	O
sleep	O
(	O
stages	O
3	O
and	O
4	O
)	O
,	O
people	O
with	O
schizophrenia	B-Application
have	O
been	O
shown	O
to	O
have	O
reduced	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
,	O
although	O
delta	B-Algorithm
waves	I-Algorithm
have	O
also	O
been	O
shown	O
to	O
be	O
increased	O
during	O
waking	O
hours	O
in	O
more	O
severe	O
forms	O
of	O
schizophrenia	B-Application
.	O
</s>
<s>
A	O
recent	O
study	O
has	O
shown	O
that	O
the	O
right	O
frontal	O
and	O
central	O
delta	B-Algorithm
wave	I-Algorithm
dominance	O
,	O
seen	O
in	O
healthy	O
individuals	O
,	O
is	O
absent	O
in	O
patients	O
with	O
schizophrenia	B-Application
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
negative	O
correlation	O
between	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
and	O
age	O
is	O
also	O
not	O
observed	O
in	O
those	O
with	O
schizophrenia	B-Application
.	O
</s>
<s>
Low-voltage	O
irregular	O
delta	B-Algorithm
waves	I-Algorithm
,	O
have	O
also	O
been	O
found	O
in	O
the	O
left	O
temporal	O
lobe	O
of	O
diabetic	O
patients	O
,	O
at	O
a	O
rate	O
of	O
56%	O
(	O
compared	O
to	O
14%	O
in	O
healthy	O
controls	O
)	O
.	O
</s>
<s>
showed	O
that	O
the	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
of	O
these	O
patients	O
in	O
stages	O
3	O
and	O
4	O
sleep	O
were	O
often	O
interrupted	O
by	O
alpha	O
waves	O
.	O
</s>
<s>
They	O
later	O
showed	O
that	O
depriving	O
the	O
body	O
of	O
delta	B-Algorithm
wave	I-Algorithm
sleep	O
activity	O
also	O
induced	O
musculoskeletal	O
pain	O
and	O
fatigue	O
.	O
</s>
<s>
In	O
long-term	O
alcohol	O
abuse	O
,	O
the	O
influences	O
of	O
alcohol	O
on	O
sleep	O
architecture	O
and	O
reductions	O
in	O
delta	B-Algorithm
activity	I-Algorithm
have	O
been	O
shown	O
to	O
persist	O
even	O
after	O
long	O
periods	O
of	O
abstinence	O
.	O
</s>
<s>
Slow	O
waves	O
,	O
including	O
delta	B-Algorithm
waves	I-Algorithm
,	O
are	O
associated	O
with	O
seizure-like	O
activity	O
within	O
the	O
brain	O
.	O
</s>
<s>
W	O
.	O
Grey	O
Walter	O
was	O
the	O
first	O
person	O
to	O
use	O
delta	B-Algorithm
waves	I-Algorithm
from	O
an	O
EEG	B-Application
to	O
locate	O
brain	O
tumors	O
and	O
lesions	O
causing	O
temporal	O
lobe	O
epilepsy	O
.	O
</s>
<s>
Neurofeedback	B-Application
has	O
been	O
suggested	O
as	O
a	O
treatment	O
for	O
temporal	O
lobe	O
epilepsy	O
,	O
and	O
theoretically	O
acts	O
to	O
reduce	O
inappropriate	O
delta	B-Algorithm
wave	I-Algorithm
intrusion	O
,	O
although	O
there	O
has	O
been	O
limited	O
clinical	O
research	O
in	O
this	O
area	O
.	O
</s>
<s>
Delta	B-Algorithm
waves	I-Algorithm
and	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
are	O
marked	O
,	O
in	O
most	O
people	O
,	O
by	O
an	O
apparently	O
unconscious	O
state	O
,	O
and	O
the	O
loss	O
of	O
physical	O
awareness	O
as	O
well	O
as	O
the	O
"	O
iteration	O
of	O
information	O
"	O
.	O
</s>
<s>
Delta	B-Algorithm
wave	I-Algorithm
activity	O
has	O
also	O
been	O
purported	O
to	O
aid	O
in	O
the	O
formation	O
of	O
declarative	O
and	O
explicit	O
memory	O
formation	O
.	O
</s>
<s>
While	O
most	O
drugs	O
that	O
affect	O
sleep	O
do	O
so	O
by	O
stimulating	O
sleep	O
onset	O
,	O
or	O
disrupting	O
REM	O
sleep	O
,	O
a	O
number	O
of	O
chemicals	O
and	O
drugs	O
have	O
been	O
shown	O
to	O
alter	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
.	O
</s>
<s>
Delta	O
sleep-inducing	O
peptide	O
,	O
as	O
the	O
name	O
suggests	O
,	O
induces	O
delta	B-Algorithm
wave	I-Algorithm
EEG	B-Application
activity	O
.	O
</s>
<s>
Alcohol	O
reduces	O
SWS	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
,	O
thereby	O
restricting	O
the	O
release	O
of	O
growth	O
hormone	O
(	O
GH	O
)	O
by	O
the	O
pituitary	O
.	O
</s>
<s>
The	O
muramyl	O
peptide	O
,	O
muramyl	O
dipeptide	O
(	O
MDP	O
,	O
N-acetylmuramyl-L-alanyl-D-isoglutamine	O
)	O
has	O
been	O
shown	O
to	O
increase	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
during	O
slow	O
wave	O
sleep	O
.	O
</s>
<s>
While	O
hypnotics	O
like	O
zolpidem	O
increase	O
slow	O
wave	O
sleep	O
,	O
they	O
do	O
not	O
increase	O
delta	B-Algorithm
wave	I-Algorithm
activity	O
,	O
and	O
instead	O
increase	O
spindle	O
activity	O
during	O
slow	O
wave	O
sleep	O
.	O
</s>
<s>
Administration	O
of	O
high-dose	O
nitrous	O
oxide	O
is	O
associated	O
with	O
transient	O
,	O
large	O
amplitude	B-Application
slow-delta	O
oscillations	O
.	O
</s>
<s>
Diets	O
very	O
low	O
in	O
carbohydrates	O
,	O
such	O
as	O
a	O
ketogenic	O
diet	O
,	O
have	O
been	O
shown	O
to	O
increase	O
the	O
amount	O
of	O
delta	B-Algorithm
activity	I-Algorithm
and	O
slow	O
wave	O
sleep	O
in	O
healthy	O
individuals	O
.	O
</s>
