PSY1005S - Intro to Psych pt2
Written by: Lekia Thaver
Consciousness
Consciousness = Consciousness is the awareness of everything that is going on
around you and inside your head at any given moment, including thoughts,
sensations, and feelings.
According to Neuroscience = consciousness is generated by a set of action potentials
during communication amongst neurons, which creates perception, memory, or
experience.
According to global workspace theory = spotlight of selective attention which
involves level of arousal (measured by Glascow Coma Scale) /awakeness vs
awareness & attention (both are important aspect of consciousness)
States of Consciousness:
1. Waking Consciousness
2. Altered States of Consciousness (e.g., daydreaming, drugs, meditation, hypnosis, and
sleep)
Sleep: (in healthy individuals)
Why do we sleep?
= Sleep is one of the human body’s biological rhythms therefore a natural cycle of activity.
= Sleep deprivation leads to impaired physical and mental and emotional functioning
= Sleep is NB for memory formation and the ability to think
= NB for physical and mental health
= Sleep problems can contribute to angina, arthritis, chronic lung disease (physical) and
depression (mental)
Circadian rhythms = sleep is controlled by these as follows:
The melatonin cycle
- Light = stimulates the suprachiasmatic nucleus [SCN] (within hypothalamus)
- This signals for the pineal gland to secrete melatonin as this activates one will
become drowsy.
- As daylight fades more is secreted.
- As daylight increases the SCN signals the pineal gland to stop secretion of melatonin
and body awakens. (Therefore consider the effect of light emitting tech before sleep
and melatonin drugs)
, The SCN POSTITON IS SIGNIFCANT as it is situated above the optical chiasma (part of
NB!!
the optic nerve transmitting signals from the eye to the rest of the brain). In the eyes
light is converted to electrical impulses that travels via the neurons (optical nerve) to
the brain.
How much sleep?
- Young adults need between 7 – 9 h of sleep per night BUT this decreases as one
ages.
Sleep is divided into: NREM (aka non-REM) & REM sleep
1. NREM
- Broken into stages i.e. N1; N2 & N3
, - From stage N1-3 sleep gets deeper & brainwaves change.
- Stage N1 = is light sleep and it’s the ‘twilight zone’ between wake and asleep.
• Brain wave activity slows down
• When awoken, one wouldn’t think that one was asleep
• Hypnogogic images or hallucinations occur
• Hypnic jerks
- Stage N2
• Drifts deeper into sleep
• Body temperature drops, heart rate slows down and breathing becomes
shallow and irregular
• Brain waves slow down further and shows spindles (and K-complexes)
- Stage N3
• Slowest and deepest brain waves
• Very deep sleep - also called slow wave sleep (SWS)
• Very difficult to wake someone from this stage of sleep
• Growth hormones are released – children grow and adults repair
• Children spend a larger percentage of their sleep in SWS so that their bodies
can grow (and it’s even harder to wake children from this stage than adults!)
2. REM
- Now a sleeping person will go back to lighter sleep through N2 into REM
- Brain wave activity resembles wakefulness
- Body temp rises to near-waking levels
- Eyes move rapidly – hence Rapid Eye Movement (REM) sleep
- When awakened, one will almost always reports having a dream
- REM dreams are more vivid, detailed, longer, bizarre and emotional
- Sleep paralysis
Written by: Lekia Thaver
Consciousness
Consciousness = Consciousness is the awareness of everything that is going on
around you and inside your head at any given moment, including thoughts,
sensations, and feelings.
According to Neuroscience = consciousness is generated by a set of action potentials
during communication amongst neurons, which creates perception, memory, or
experience.
According to global workspace theory = spotlight of selective attention which
involves level of arousal (measured by Glascow Coma Scale) /awakeness vs
awareness & attention (both are important aspect of consciousness)
States of Consciousness:
1. Waking Consciousness
2. Altered States of Consciousness (e.g., daydreaming, drugs, meditation, hypnosis, and
sleep)
Sleep: (in healthy individuals)
Why do we sleep?
= Sleep is one of the human body’s biological rhythms therefore a natural cycle of activity.
= Sleep deprivation leads to impaired physical and mental and emotional functioning
= Sleep is NB for memory formation and the ability to think
= NB for physical and mental health
= Sleep problems can contribute to angina, arthritis, chronic lung disease (physical) and
depression (mental)
Circadian rhythms = sleep is controlled by these as follows:
The melatonin cycle
- Light = stimulates the suprachiasmatic nucleus [SCN] (within hypothalamus)
- This signals for the pineal gland to secrete melatonin as this activates one will
become drowsy.
- As daylight fades more is secreted.
- As daylight increases the SCN signals the pineal gland to stop secretion of melatonin
and body awakens. (Therefore consider the effect of light emitting tech before sleep
and melatonin drugs)
, The SCN POSTITON IS SIGNIFCANT as it is situated above the optical chiasma (part of
NB!!
the optic nerve transmitting signals from the eye to the rest of the brain). In the eyes
light is converted to electrical impulses that travels via the neurons (optical nerve) to
the brain.
How much sleep?
- Young adults need between 7 – 9 h of sleep per night BUT this decreases as one
ages.
Sleep is divided into: NREM (aka non-REM) & REM sleep
1. NREM
- Broken into stages i.e. N1; N2 & N3
, - From stage N1-3 sleep gets deeper & brainwaves change.
- Stage N1 = is light sleep and it’s the ‘twilight zone’ between wake and asleep.
• Brain wave activity slows down
• When awoken, one wouldn’t think that one was asleep
• Hypnogogic images or hallucinations occur
• Hypnic jerks
- Stage N2
• Drifts deeper into sleep
• Body temperature drops, heart rate slows down and breathing becomes
shallow and irregular
• Brain waves slow down further and shows spindles (and K-complexes)
- Stage N3
• Slowest and deepest brain waves
• Very deep sleep - also called slow wave sleep (SWS)
• Very difficult to wake someone from this stage of sleep
• Growth hormones are released – children grow and adults repair
• Children spend a larger percentage of their sleep in SWS so that their bodies
can grow (and it’s even harder to wake children from this stage than adults!)
2. REM
- Now a sleeping person will go back to lighter sleep through N2 into REM
- Brain wave activity resembles wakefulness
- Body temp rises to near-waking levels
- Eyes move rapidly – hence Rapid Eye Movement (REM) sleep
- When awakened, one will almost always reports having a dream
- REM dreams are more vivid, detailed, longer, bizarre and emotional
- Sleep paralysis
