Variations in ConsciousnessContinued

01-04-2010

Welcome to 2010!!!

Drill 01-04-2010

• Experts say, “Early to rise isn’t making kids wise – it’s making them sleepy.” Should early-start schools move to a later start time or is this impractical? Explain your responses.

Have you continued your sleep diary through break?

• If not, be sure to add tonight to your diary. You should have at least 3 – 5 nights. The more the better!

Important Dates

• January 4, 5 & 6 ~ Finish Chapter 5• January 7 ~ Chapter 5 Vocabulary Due• January 8 ~ Take Home Test Chap. 5 • January 11 ~ Test Due & Begin Chap. 4

» Chap. 4 Vocabulary #1 ~ Due Jan. 12» Chap. 4 Vocabulary #2 ~ Due Jan. 19» Chap. 4 Vocabulary #3 ~ Due Jan. 26

• January 28 ~ Chapter 4 Test• January 29 ~ Begin Chapter 6

Sleep Odds & Ends

• Age ~ alters sleep cycle– Newborns

• Sleep 6 to 8 times, exceeding 16 hours of total sleep

– Infants• Spend much more time in REM sleep than adults (50%

for infants, 20% for adults), but continues to decline as one ages

– Adults• Shifts are seen toward lighter sleep & cause increased

waking during the night

SleepOdds & Ends

• Culture – Co-Sleeping

– The practice of children and parents sleeping together» In western culture, this is discouraged» In Japanese cultures, it is emphasized as

interdependence and group harmony» Co-sleeping is more normative than not ~ and

pressure against it appears to be an urban & western phenomonon

– Napping– In many societies, shops close and activities are halted

in the afternoon for a 1 – 2 hour nap– “Siesta cultures” are found in the tropical regions of the

world (afternoon is hottest part of the day)– Not found in industrial societies

SleepOdds & Ends

• Neural Bases of Sleep– No single structure in the brain serves as a “sleep

center”• Sleep & waking appears to be regulated by many

subcortical structures in the brain– Reticular Formation – in the core of the brainstem,

important in sleep

» Ascending Reticular Activating System (ARAS) – consists of the afferent fibers running through the reticular formation that influence physiological arousal – projects into many areas of the cortex

– Pons

– Medulla, Thalamus, Hypothalamus, & Limbic System

– Neurotransmitters Serotonin & GABA

Evolution & Sleep

• How is sleep adaptive?– 1. Sleep evolved to conserve energy

» Warmbloodedness requires constant maintenance of high body temps

– 2. Immobilization associated with sleep reduces the exposure to predators & other dangers

– 3. Helps organisms restore energy & resources depleted by waking activities

Sleep Deprivation

• Complete Deprivation

• Negative effects on mood, cognitive tasks & perceptual-motor tasks

• When motivated, subjects can still perform well on some of these tasks

• The effects would be more severe, but most people have a hard time going for LONG periods without sleep

• Partial Deprivation• Sleep experts believe

that much of American society chronically suffers from this

• Impairs attention, reaction time, motor coordination, and decision making

Did you know?

• Why do we yawn?• A yawn is a reflex of inhalation and exhalation

that draws more oxygen into the bloodstream. A reflex is a built-in physical reaction that people often do not have control over. A yawn is often associated with a person being tired, but this is not always the cause for a yawn. People yawn for many reasons including stress, boredom, emotion and over-work.

Is Yawning Contagious?

• If one person yawns, this appears to cause another person to yawn. Researchers have found that 40-60% of people who see a picture of someone yawning will yawn themselves. Even reading the word YAWN can make people yawn.

• Although this “contagious” yawning behavior is not understood, it has been suggested that this could be the result of an unconscious herding behavior — a subtle way to communicate group behavior, such as when a birds follow the behavior of one bird, and all rise together as a whole flock.

• Maybe a yawn is a signal to the group that it’s time to go to sleep. Or if someone yawns when they’re bored, it may be a sign to change the topic of conversation.