Why We Sleep: Rest and Activity are the Steps of Progress

04/20/23 1

Why We Sleep:Why We Sleep:Rest and Activity are the Rest and Activity are the

Steps of ProgressSteps of Progress

You and Your Brain

Sun Monday Tuesday Wed Thursday Friday Sat

Sept 11: Paradigms 13: Brain Develop-ment

Sept Mongolia Conference

Sept Yom Kippur 27: Sleeping

28: TM and TC

Oct 2: Science and Pseudoscience

4: Other Meditations

Oct 9: Cosmic Consciousness

Timeline: 7:45 – 9:00

Drfredtravis.com for copy of lecture power points

Available at Amazon for the Kindle.

Plus, I have copies for sale.

WholenessWholeness

Sleeping and dreaming repair Sleeping and dreaming repair the brain and are essential the brain and are essential maintain optimal health and maintain optimal health and uphold growth towards uphold growth towards enlightenment. Rest and enlightenment. Rest and activity are the steps of activity are the steps of progress.progress.

Adenosine Receptors: Adenosine Receptors: The cellsThe cells’’ accountant accountant

Rhythms in SleepRhythms in Sleep

• Most of the organisms living on Most of the organisms living on earth show 24 hour circadian earth show 24 hour circadian rhythms that are endogenously rhythms that are endogenously controlled by biological clocks.controlled by biological clocks.

• In mammals these rhythms are In mammals these rhythms are generated by the circadian generated by the circadian pacemaker located in the pacemaker located in the suprachiasmatic nucleus or SCN suprachiasmatic nucleus or SCN of the hypothalamus.of the hypothalamus.



During the daytime the SCN During the daytime the SCN neurons fire rapidly but at night neurons fire rapidly but at night they fire very slowly. This was a they fire very slowly. This was a single rat neuron from the SNC single rat neuron from the SNC maintaining a basic circadian maintaining a basic circadian rhythm in a dish.rhythm in a dish.


Rhythms: Pineal GlandRhythms: Pineal Gland

The SCN takes the information on The SCN takes the information on the lengths of the day and night the lengths of the day and night from the retina, interprets it, and from the retina, interprets it, and passes it on to the pineal gland, a passes it on to the pineal gland, a tiny structure shaped like a pine tiny structure shaped like a pine cone and located in the center of cone and located in the center of the brain. the brain.


In response, the pineal secretes the In response, the pineal secretes the hormone melatonin. Secretion of hormone melatonin. Secretion of melatonin peaks at night and ebbs melatonin peaks at night and ebbs during the day and its presence during the day and its presence provides information about night-provides information about night-length. length.


The pineal gland also plays an The pineal gland also plays an important role in animals in setting important role in animals in setting seasonal rhythms. seasonal rhythms.

The Pineal GlandThe Pineal Gland

Two Process Two Process Model of SleepModel of Sleep

• Sleep pressure—how long Sleep pressure—how long since you have slept since you have slept (“adenosine-accountant”).(“adenosine-accountant”).

• Circadian rhythms Circadian rhythms

Light Sensitive Circadian Light Sensitive Circadian rhythms (24-hour cycles) in rhythms (24-hour cycles) in

physiological processes physiological processes of all mammalsof all mammals

Midnight 6 AM Noon 6 PM Midnight

Gre

ater

Dro

wsi

nes

s

1 2 3 4 5 6 7 8

4

3

2

1

REM

AWAKE

Sle

ep S

tag

es

Hours of Sleep

REM Stage

NREM

Adapted from Berger RJ. The sleep and dream cycle. In: Kales A, ed. Sleep Physiology & Pathology: A Symposium. Philadelphia: J.B. Lippincott; 1969.

Normal Sleep Cycles in Normal Sleep Cycles in Young Adults (Sleep/Dream)Young Adults (Sleep/Dream)

SleepSleepSleepSleep

Brain Stem NucleiBrain Stem Nuclei

DreamingDreamingDreamingDreaming

Brain Blood Flow during Sleep

You wake up in reverse—thalamus first and then the CEO, called sleep inertia.

1st CEO

1 2nd Thalamus

2

Blood Flow and Dreaming (REM)

Desseilles et al, 2012. Consciousness and Cognition

Sleeping and Dreaming Sleeping and Dreaming Repairs the BrainRepairs the Brain

1.1. Replenish brain energy resources Replenish brain energy resources (adenosine triphosphate) and (adenosine triphosphate) and intracellular house-keeping—intracellular house-keeping—replace neurotransmitter vesicles.replace neurotransmitter vesicles.

2.2. Conduct neural plasticity—Conduct neural plasticity—maintain appropriate connections maintain appropriate connections and eliminate accidental and eliminate accidental connections.connections.

Ursin, et al. (2005) Sleep duration, subjective sleep need, and sleep habits in 8860 adults. Sleep. 28,(10), 25-34.

How Much Sleep Do I Need?

• If you don’t get enough If you don’t get enough sleep…sleep…

Restricting Sleep--Restricting Sleep--Reduced VigilanceReduced Vigilance

Restricting Sleep--Restricting Sleep--Reduced VigilanceReduced Vigilance

Base- 1 2 3 4 5 6 7 line

Days on Experimental Schedule

Vig

ilan

ce L

evel

0.5

0.4

0.3

0.2

0.1

0.0

Better

Worse

Effect of Fatigue Effect of Fatigue on Medical Studentson Medical Students

• JAMA 2005JAMA 2005– Heavy-call residents (every 3rd Heavy-call residents (every 3rd

night) vs low-call residents who night) vs low-call residents who drank three beers (BAC drank three beers (BAC level .08)level .08)

Similar impairments inSimilar impairments in

–Sustained attentionSustained attention– VigilanceVigilance– Performance on a simulated Performance on a simulated

driving test.driving test.• Anyone working > 70 hrs/week Anyone working > 70 hrs/week

functions at the level of being legally functions at the level of being legally drunk (BAC = .08).drunk (BAC = .08).

Rested 36-hour Sleep Dep.

Amygdala Amygdala 60% more 60% more active active and 3 and 3 times times greater greater area area when when tired.tired.Yoo et al. (2007) The human emotional brain without sleep -- a prefrontal

amygdale disconnect.Current Biology, Vol. 17, No. 20, R877-R878.

Fatigue Makes Experiences More Fatigue Makes Experiences More IntenseIntense

Main Point Main Point Sleep involves active processes of Sleep involves active processes of repairing brain circuits after a day of repairing brain circuits after a day of activity. Dreaming supports this activity. Dreaming supports this through auto-activation leading to through auto-activation leading to structured forgetting. Brain circuits structured forgetting. Brain circuits created during the day are erased if created during the day are erased if they are not deep. Rest and activity are they are not deep. Rest and activity are the steps of progress during waking the steps of progress during waking and during sleeping and dreaming.and during sleeping and dreaming.

How to get good sleep, part 1How to get good sleep, part 1

• Keep a regular schedule. Keep a regular schedule.

• Be consistent with sleep times, Be consistent with sleep times, including weekends.including weekends.

• Exercise regularly. Exercise regularly.


• Eliminate caffeine and, of course, Eliminate caffeine and, of course, alcohol and nicotine.alcohol and nicotine.

• Eliminate TV and computer use later Eliminate TV and computer use later in the evening.in the evening.

• Don't use your time in bed to plan Don't use your time in bed to plan the next day.the next day.


• Switch off lights. Switch off lights.

• To get more enough sleep, go to bed To get more enough sleep, go to bed 15 minutes earlier every 315 minutes earlier every 3rdrd-4-4thth day. day.

• When you wake in the night, don't When you wake in the night, don't panic and worry that you aren't panic and worry that you aren't getting enough rest. It's natural, so getting enough rest. It's natural, so just take it easy and enjoy your rest. just take it easy and enjoy your rest.

Group Exercise Group Exercise

Witnessing sleep is a marker of Witnessing sleep is a marker of Cosmic Consciousness. What Cosmic Consciousness. What function does sleep play in function does sleep play in Cosmic Consciousness? Cosmic Consciousness?

Maharishi on SleepMaharishi on SleepSleep is the blessing of God,Sleep is the blessing of God,Feel love of God,Feel love of God,Lie in the showers of His blessing.Lie in the showers of His blessing.Let your heart melt in the love of Let your heart melt in the love of God.God.Sleep in the thought of God and in Sleep in the thought of God and in the love. the love. It is not necessary to say anything, It is not necessary to say anything, But feeling of God is of maximum But feeling of God is of maximum value.value.The love flows.The love flows.Sleep is only at the surface.Sleep is only at the surface.Sleep in the warmth of Divine Grace Sleep in the warmth of Divine Grace Without any words -- only this Without any words -- only this feeling.feeling.

Maharishi, Maharishi, 19621962

Cerebral Blood Flow during Waking, Dreaming and Sleeping

Braun et al, 1997, Brain

Computer analogy of sleep Computer analogy of sleep and dreamingand dreaming

• During the day, store data in RAM. During the day, store data in RAM. • During NREM sleep, write data to disk. During NREM sleep, write data to disk. • During dreaming REM, disk defragmentation. During dreaming REM, disk defragmentation.

– Repeat the write-and-defragment cycle until all data is Repeat the write-and-defragment cycle until all data is written to the disk and your RAM is clear and ready for a written to the disk and your RAM is clear and ready for a new day of learning. new day of learning.

• At waking up, you reboot the computer. If At waking up, you reboot the computer. If you reboot early with the use of an you reboot early with the use of an alarm alarm clockclock, you often leave your disk fragmented. , you often leave your disk fragmented.

Meter Reading Errors

Time of Day

4000

5000

6000

7000

8000

9000

10,000

11,000

Circadian Rhythms and Circadian Rhythms and Performance ErrorsPerformance Errors


Mitler MM, et al. Sleep. 1988.

Sweden N = 74,927

No

. of

Err

ors

Circadian Rhythms and Vehicle Circadian Rhythms and Vehicle Accident DataAccident Data

Fatigue-Related Accidents

Time of Day


International Data N = 60521200

1100

1000

900

800

700

600

500

400

300

200

100

Mitler MM, et al. Sleep. 1988.

No

. of

Acc

iden

ts

Sleep Sleep DeprivedDeprivedSleep Sleep DeprivedDeprived

RestedRested

FatigueFatigue

Sleep Effects Day 2 RecallSleep Effects Day 2 Recall

Red: Sleep deprivedRed: Sleep deprivedBlue: Full sleepBlue: Full sleep

Sleep Effects Day 2 RecallSleep Effects Day 2 Recall

Red: Sleep deprivedRed: Sleep deprivedBlue: Full sleepBlue: Full sleep

How Much Sleep Do I Need?

National Sleep Foundation Poll in 20001. 33% adult Americans < 6.5 hours per night2. 45% will sleep less to accomplish more

Newborns : 16 to 18 hours Newborns : 16 to 18 hours Age 1 : 13 to 14 hoursAge 1 : 13 to 14 hoursTeenagers : > 9 ½ hoursTeenagers : > 9 ½ hoursAdults : 8 hours and 20 minutesAdults : 8 hours and 20 minutesSeniors : 8 hours Seniors : 8 hours

Documents

Why We Sleep: Rest and Activity are the Steps of Progress