What is Consciousness?

Our awareness of ourselves and environment (slippery concept)

Levels of ConsciousnessConscious- Active Awareness

Preconscious- Stored memories you can recall

at any time

Subconscious- Routine activities that you don’t need to think about

Unconscious- memory, ideas, that our consciousness cannot handle or has stored deep away

Consciousness vs. Altered Consciousness

Regular Consciousness• Gather information though

the senses (seeing, hearing, ext…)

• Reasoning• Remembering• Daydream/Fantasies

Altered States of Consciousness

• Sleep • Hypnosis • Under the Influence of

Drugs

Our Biological Clocks

• Circadian Rhythms govern our bodies

• Daily pattern of activity, according to light and day

• Humans entrained on 24-hour cycle– Entrain: adjust an internal rhythm

so that it synchronizes with an external cycle, such as that of light and dark

• Plants and animals also have them

What Controls our Biological Clocks?• Hypothalamus- keeps body in tune with your day

(nervousness, hunger, temperature, sleep/wake cycles)– Controlled by cluster of neurons (SCN) – SCN gets info from eye about light/dark and then releases

chemicals to regions of the brain

• Hormones– Melotonin- released by Pineal Gland (which gets info from eye);

triggers sleep, relaxation • increases with longer/shorter periods of dark

– Epinephrine- wake, alertness= jump starts heartbeat, surges in a.m.

• Variations to Circadian rhythm– Jet Lag– Night shift– SAD (Seasonal Affective Disorder)

How do we know what’s going on in our brains during sleep?

• EEG’s – records electrical activity of the brain = brain waves

Sleep StagesStage 2:Activity: sleep spindles, body temp drops.Brain waves: Theta – a bit slower

Stage 3Activity: Pulse rate and breathing slowed down, more difficult to wake up Brain waves: delta, slower waves

Stage 4Activity: Deep sleep, only loud noises could awake youBrain waves: delta

Stage 1:Activity: relaxation, can be easily awakened, hypnic jerksBrain Waves: Alpha- slow regular rhythm

REM (rapid eye movement): Activity: blood pressure and heartbeat up, body paralyzed --- start to DREAMBrain Waves: active – MOST IMPORTANT STAGE!

NREM (Non Rapid Eye Movement)Stages 1 - 4

• Dreaming possible– Partial Images and Stories, harder to remember

• Brain goes idle • Body refuels• Growth Hormone released– Hair and nails grow

• Sleep walking possible

Brain waves during sleep cycles

Sleep and Age

• Newborns spend 16-20 hrs/day sleeping

• Elderly spend 6 or less in one period of time

• REM sleep goes down as we age

Sleep theories – why is it important?

• Adaptive – ancestors slept to survive when it was dark

Sleep theories

• Restorative – brain repairs, reorganizes, and re-energizes for next day– Memory consolidated