Consciousness: Attention & Sleep L5

Attention

focusing consciousness on specific stimuli or aspect of stimuli

Selective attention

focusing on specific information while ignoring other information

Intentional blindness

failing to detect available stimuli due to selective attention

Change blindness

failing to detect changes in stimuli due to selective attention

Circadian rhythm

biological clock (controlled by hypothalamus)l

Superchiasmatic nucleus (SCN)

sensitive to changes in light

in hypothalamus

controls pineal gland

Secretes melatonin- hormone that cluses sleepiness

SCN in darkness & light

darkness —> SCN direct pineal gland to secrete melatonin

light —> SCN directs pineal gland to stop secreting melatonin

Implications of circadian rhythms & light

artificial lighting interferes with circadian rhythm

Sleep stages

~90 min cycles of sleep stages

• Non rapid eye movement (N-REM) 3 stages

  • N1- light sleep

  • N2- true sleep

  • N3- deep sleep

• Rapid eye movement (REM)

N1

light sleep (10-15 min)

• hypnic or hypnagogic jerk

• hypnagogic hallucinations

N2

true sleep (15-20 min)

• brain activity slows

• reductions in hear rate & muscle tension

N3

deep sleep

• further slowing of brain activity

• hard to awaken, disoriented when awaken

  • growth hormones released form pituitary

REM

brain waves resemble wakefulness

eye moves back & forth

hear rate, blood pressure, breathing- rapid or irregular

sleep paralysis

“paradoxical sleep”

dreams

Evolutionary/adaptive theory of sleep

protection

not out and vulnerable to predators in the dark

Restorative theory of sleep

sleep supports growth & healing

product of growth hormone

supports immune functioning

• sleep deprivation —> slower healing reduced immune system activity

Information processing theory of sleep

sleep supports cognitive process

supports learning

restores & rebuilds memories

Supports creative thinking

• sleep deprivation —> impairment of memory function

Effects of sleep deprivation

irritability, mood disruption

increased risk of depression

increased risk of obesity

Manifest content

actual images in the dream

Latent content

the unconscious thoughts, feelings & wishes behind the manifest content

Activation synthesis

brain internally generated signals from dreams

• random neural signals

Information processing

memories of events form dreams

• pressing things we learn in our dreams

perserving neural pathwasy

purpose of dreaming is to provide brain stimulation