About a year ago at my college a hypnotist came for entertainment, and
made people do all sorts of funny stuff. One of the things he made a
young man do was go into a 'deep sleep' where it was obvious all of
his muscles were very relaxed and he was out. Afterwards when speaking
with some of the participates (the deep sleeper included) they said
they felt extremely refreshed, moreso than they can ever remember. I
asked the hypnotist about it and he told me that hypnotism puts you in
a deeper state of sleep, which most people only experience for about
two or three hours during the night. Although people sleep for longer
than that, they are in other stages of sleep that aren't as
refreshing.

This also reminded me of a friend's father who sleeps on average
around 4 hours of sleep a night and always looks very energetic. I
asked him about it and he said he sleeps really well and doesn't need
more sleep than that.

My question is, what is this stage of sleep called, and is it possible
to induce such a state of sleep? Perhaps through self-hypnosis? If so,
where would I go about finding resources, etc. to aid me in trying to
do this. My goal is to be able to make better use of my sleep time
and/or take power naps in the middle of the day. Thanks!!!

The deepest stage of sleep is called "Stage 4 Sleep," "Slow Wave
Sleep," or "Delta Sleep." Here are a few online references:

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"The state of hypnosis is a specific state of mind that can be
measured by brain waves. There are various states of mind, or brain
wave patterns, which occur in your brain each and every day. They are:

Beta - awakened alertness. 

Alpha - heightened creativity and enhanced relaxation.   Hypnosis is
somewhere between sleep and wakefulness.

Theta -  the brink of sleep, where you may have creative insights in
this stage, just as many scientists, poets, and artists have

Delta - this is the deep sleep stage." 

Millenium Medical Group: Hypnosis
http://www.milleniummedicalgroup.com/hypnosis/

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"As we fall asleep, we enter the transition sleep called Stage 1 and
begin our first 'sleep cycle'. Within a few minutes we evolve into our
'baseline' sleep called Stage 2. It is from Stage 2 sleep that the
other three stages emerge. Stage 2 sleep occupies approximately 50-65%
of our sleep time. Within 15-20 minutes we have slowly evolved into
Stage 3 then Stage 4 sleep, often called delta sleep or slow wave
sleep because of the very high voltage, slow brain waves. Delta sleep
is similar to being in a coma, but unlike a coma, it's reversible."

Sleep Doctor: The Stages of Sleep
http://www.sleepdoctor.com/stages.htm

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"The deepest sleep occurs in Stage 4. Stage 4 is characterized by:

- The brain waves (called delta brain waves) are quite large, making a
slow, jagged pattern on the EEG.
- The sleeper experiences virtual oblivion. If the sleeper is a
sleepwalker or a bed wetter, those activities will begin in this
phase.
- Bodily functions continue to decline to the deepest possible state
of physical rest.
- This first period of deep sleep is the deepest. The sleeper awakened
from deep sleep will probably be groggy, confused, or disoriented. He
or she may experience 'sleep inertia' or 'sleep drunkenness,' seeming
unable to function normally for quite some time."

Holistic Online: Sleep Stages
http://www.holistic-online.com/Remedies/Sleep/sleep_stages-1-4NREM.htm

----------------------

"Sleep consists of cycles. Prior to sleep, the brain displays Beta
waves. As we close our eyes and think of nothing we go into Alpha, and
when sleep starts, the brain displays Theta waves. There are four
stages of sleep, from Stage 1 (the lightest sleep) to Stage 4 (the
deepest sleep). During the first cycle of sleep the brain slows down
and as people descend from Stage 1 to stage 4, the brain goes from
Theta to Delta... The amount of time spent in Stage 4 grows
progressively shorter across the cycles, and the amount of time in
Stage 1-REM grows progressively longer. The amount of time spent in
the various stages is: Stage 1- 25%, Stage 2 - 45%, Stage 3 -15%, and
Stage 4 - 15%."

Michael T Hynan Home Page, The University of Wisconsin-Milwaukee:
Sleep and Dreams
http://www.uwm.edu/People/hynan/205/205DREAM.html

----------------------

Regarding methods for inducing Delta sleep, I've found several.

The Delta Sleep System is an audio CD developed by Dr. Jeffrey
Thompson. There are several reviews of the Delta Sleep System at
Amazon.com (but I've found a much better price than Amazon's, so keep
reading.)

Amazon.com: Delta Sleep System
http://www.amazon.com/exec/obidos/tg/detail/-/B00005BIY7/qid=1044826040/sr=8-1/ref=sr_8_1/002-0925981-2968868?v=glance&s=music&n=507846

The best price I've found on the Delta Sleep System is at
Overstock.com, where you can buy this CD (which lists at $14.99) on
sale for $3.99:

Overstock.com: Delta Sleep System
http://www.overstock.com/cgi-bin/d2.cgi?cid=25608&PAGE=PRODUCT&PROD_ID=44305&fp=F

Here are two brief audio clips from the Delta Sleep System:

Serenity Supply
http://serenitysupply.com/MP3/Serenitysupply.com_10010_1.mp3

Serenity Supply
http://serenitysupply.com/MP3/SerenitySupply.com_10011_1.mp3

Dr. Jeffrey Thompson has produced several other sleep-related audio
CDs:

Healing Products: Music for Your Mind, Body & Soul
http://www.healingproducts.com/BrainSets.htm

----------------------

Hypnotherapist Dean Montalbano has an interesting method of
self-hypnosis that involves the visualization of different colors to
advance through deepening trance states:

Hypnodean: Self Hypnosis
http://www.hypnodean.com/serv03.htm

----------------------

Brain Sync offers many audio programs on cassette, including this one,
which is targeted at inducing Delta sleep:

"Achieve the deep sleep states that nurture your subconscious and
bring you the wonderfully restorative slumber your body and mind
require for optimum performance. Delta frequencies, music and
subliminal messages."

Brain Sync: Deep Sleep
http://www.brainsync.com/titles/deepsleep.asp

Here is an audio sample from a Brain Sync tape called "Brain Tune-Up":

Brain Sync: Brain Tune-Up
http://www.brainsync.com/sounds/mp3/7minute.mp3

----------------------

Several sleep-related audio programs are described here:

Sleep Wellness: Audio/Music
http://www.sleepwellness.com/audioinfo.htm#6

----------------------

Here are some products that are specifically designed to help reduce
the amount of sleep you need:

Brainwave Generator: Sleep Reducer
http://www.bwgen.com/presets/desc16.htm

( NOTE: The above program works with "Brainwave Generator," which may
  be downloaded here: http://www.bwgen.com/download.htm
  or here: http://www.simtel.net/pub/dl/15525.html )

World of Alternatives: Sleep Reduction
http://www.worldofalternatives.com/sleep-reduction.htm

Hypnotism.com: Health
http://www.hypnotism.com/health.cfm

Global Hypnosis: Insomnia Relief
http://www.globalhypnosis.com/insomnia_relief.html

----------------------

In locating this information, I used various combinations of search
terms including "deep sleep," "delta sleep," "stage 4 sleep," "slow
wave sleep," "hypnosis," "self-hypnosis," and "sleep reduction."

If anything I've said is unclear or in need of explanation, or if any
of the links do not function, please request clarification before
rating my answer, and I'll gladly offer further assistance.

Best wishes,
pinkfreud