Sleep and consciousness

What is consciousness

our awareness of ourselves, thoughts and environment

Awareness of external stimuli: seeing sunlight, hearing friends voice

Awareness of internal stimuli: feeling pain, sleepiness, thoughts, emotions

conscious altering drugs

change consciousness by changing brain activity

• changes the amt of neurotransmitters in the brain

• cocaine blocks reuptake (recycling) of dopamine

• dopamine accumulates —> overstimulate neruons

• amplifies reward signal

LSDs affect on consciousness

• influences dopamine and serotonin signaling

• massive increase in brain activity compared to taking placebo

• esp in visual cortex (hallucinations)

psychoactive drugs

substance that alters perception, mood, thinking, behavior by interacting with biochemistry of the brain and body

• stimulants, depressants, opiates, psychedelics

Stimulants

• speed up activity in the CNS

• feelings of excitement, confidence, euphoria

• ex. nic, coke, caffeine, amphetamines

depressants

slow down activity in the CNS, feel calm, tired, reduce anxiety and inhibitions

ex. alc. & tranquilizers

opiates

• influence “emotional” centers of the brain

• feelings of euphoria; relieve pain

• highly addictive

psychedelics

• produce hallucinations, change thoughts, disrupt perception of time and space

• ex. LSD, shrooms

Coma

• disorder of consciousness

• no outward signs of awareness

locked in syndrome

voluntary movement largely lost (except eyeblinks)

• autonomic functions remain

  • involuntary, regulate internal organs

Stage 1 sleep

• drifting off to sleep, slow irregular brain waves

• theta waves

• limb jerks, sensation of falling

stage 2 sleep

• less sensitive to external stimulation

• sleep spindles (bursts of rapid waves)

• as much as 65% of total sleep

• minor noises wont disturb you

stage 3/4 sleep

• delta waves, slow-wave sleep

• deep sleep: breathing/pulse slowed

  • still monitor environment for potential danger

  • parents awake to crying children but not sirens

REM (rapid eye movement)

• fast waves

• increased eye movement

• loss of muscle tone

• dreaming

• brain activity similar to wakefulness

• paradoxical sleep: brain is active, body is inactive

tetris effect

• dream of falling shapes after playing tetris all day

• even in patients with amnesia who cant consciously recall playing tetris earlier in the day

  • sleep serves to unconsciously cement new info and skills in the brain

  • sleep strengthens acquired memory traces by replaying them

change blindness

• videos blinking, we didnt notice the changes until told where to look

• shows us that our conscious experience is not simply a reflection of the outside world

• more than just sensation and perception, depends on attention

sleep apnea

• breathing periodically stops

• can cause high blood pressure and irregular heartbeat

narcolepsy