Abstract

The name of my project is Sleep.  The question for my project is “Is a child’s sleep different than an adult’s sleep?”  I thought the outcome of the child and the adult sleep would be that they are the same.  I was wrong! I concluded after seeing the data that kids have more Slow Wave Sleep than adult’s because they grow (release human growth hormones) at night while they sleep.  I also found it interesting that a child’s brain waves are larger than an adult’s brain waves.

Introduction

To come up with my science project I thought about my mom and dad’s job.  I wondered if a kid’s sleep would be the same as an adult, or maybe different.  My mom said she would help me find out.  We planned to do a sleep study on both Rachel, my little sister, and on my mom.  My dad helped us by watching the monitors all night to be sure we were getting good data.  We were able to go to the sleep lab and use real sleep equipment, and I got to see how a patient’s head is measured, electrodes are applied, and how the sleep equipment is used.  It was really interesting that I got to do this project; I had a lot of fun.

Once my mom and sister were all hooked up I took pictures of all the equipment used on them, all the wires and stuff.  My mom and sister went to sleep, and in the morning after they were unhooked my mom scored the data.  Scoring is marking each 30 second page with the stage of sleep, there are about 800 pages of information for each night study!

                                  List of Materials

The equipment I needed for my experiment was electrodes, for the head, face, heart, chin, and legs (to look for leg movements), we used belts around the chest and tummy to see breathing patterns, we used snore microphones to see if anyone snored or not, we used a sensor under the nose to see the person breathe in and out, and we used a probe on the finger to see how much oxygen is in the blood.  We used the sleep lab that my dad works at so we could use the sleep equipment.  The electrodes are applied to the skin to see a person’s brain waves; the sleep equipment can magnify a person’s brain waves by up to 1 million times!  We used two sleep lab bedrooms.  And two sleep techs, my mom and dad.  Oh, and a camera to take pictures of my experiment.

                             Experiment Procedure

It took about 45 min to 1 hour to fully hook up each person.  Then we had to test the equipment to make sure it was recording all the information correctly.  Then I took some pictures.  Then we tucked in my mom and sister, and recorded all night.  Then in the morning we unhooked my mom and sister, and the equipment had to be cleaned and sterilized.  My mom then scored the data.  Later mom showed me the different stages of sleep, and I got to see the difference between adult and child sleep.

Data Collected

I learned about the different stages of sleep as part of my research for my project, here are the stages and a brief description of each one.

WAKE

Wake is when you’re awake.  The brain waves when you are awake are very fast 8-13Hz, or 8-13 waves per second in the brain.  We see wake best in the Occipital region of the brain, which is the area of the brain that controls our eyes.  It is in the lower back portion of the head.  During wake we often see eye movements or blinking, and high muscle tone in the chin also known as EMG.

Stage 1 Sleep

(Also known as stage N1)

Stage 1 sleep is a very light sleep.  When you’re in stage 1 sleep, if someone asked you a question, you might answer them, and may or may not remember.  Stage 1 sleep is slower than wake sleep, and is 4-7Hz, or 4-7 brain waves per second.  In stage 1 sleep we often see slow rolling eye movements.

Stage 2 Sleep

(Also known as stage N2)

Stage 2 sleep is a good sleep, not a light sleep, but not a deep sleep.  Stage 2 sleep is 4-7 Hz like stage 1, but also has K-complexes and sleep spindles that are seen in the central portion of the brain halfway between the ears and the top of the head.  Most adults spend the majority of their night in stage 2 sleep.

Stage 3/4 Sleep

(Also known as N3 or Slow Wave Sleep (SWS)

Stage 3 and 4 sleep is a very deep sleep.  Children have a lot of stage 4 sleep, as we get older we have less and less, and it is not uncommon for the elderly to have no Slow Wave Sleep.  If you have ever picked up a small child and they are limp like a rag doll, and very difficult to wake up this is Slow Wave Sleep.  In SWS Human Growth Hormone is released causing us to grow, and are memories are consolidated, so we are better able to remember what we learned that day.  Stage 3 and 4 sleep is known by Delta waves which are 2-4 Hz. or 2-4 brain waves per second they are very large waves that look like mountains these very large very slow waves make the brain waves look messy.

REM

(REM stands for Rapid Eye Movements)

REM sleep is when we dream.  When we dream our bodies become paralyzed, so we don’t act out our dreams and hurt ourselves.  In REM sleep the brain waves are the same as Stage 1 sleep, the chin EMG channel will be very small, because our muscles are paralyzed, and our eyes show Rapid Eye Movement.  All people dream, they may not remember, but studies done in rats show that if they are not allowed to dream they will go crazy and die!

From the scored data of the adult and child study we got a graph of the different stages of sleep, to compare.  If you look at the child graph you will see that there is a lot more of the blue color or stage 4 sleep.  You will also notice that the child graph has more red patches or REM sleep than on the adult.

The graphs wouldn't transfer.

The next set of data is a chart showing the minutes of each stage of sleep and the percent of time both the child and adult spent in each stage of sleep.  The child had 25.8% of Total Sleep Time in Stage 3, the adult only had 6.5% of Total Sleep Time in Stage 3.  Do you see the difference?  Notice the adult had more stage 1 and 2 sleep than the child.  In this case the child also had more REM sleep.

                        Duration        *% TST 

Stage 1:               5.5 min        1.2%                               

Stage 2:           218.0 min        49.2% 

Stage 3:           114.5 min        25.8%                          

<font face="Calibri">REM:               105.0 min         23.7%    </font>

Adult Sleep Stages

                          Duration         * % TST

Stage 1:             16.0 min               7.2%                               

Stage 2:           157.5 min             70.8%        

Stage 3:             14.5 min               6.5%                                 

<font face="Cambria">REM:                34.5 min             15.5%</font>