Consciousness - Attention and Sleep (Exam 2)

Attention

ocusing consciousness on specificstimuli or aspect of stimuli

Selective attention

focusing on specific information while ignoring other information

Inattentional blindness

failing to detect available stimuli due to selective attention

Change blindness

failing to detect changes instimuli due to selective attention

What controls our sleep-wake cycle?

Our sleep-wake cycle is controlled by two main systems: the brain's internal "circadian clock" and the body's "sleep drive".The circadian clock, a part of the hypothalamus called the suprachiasmatic nucleus (SCN), is a 24-hour internal clock that is reset by light signals from the eyes, while the sleep drive builds the longer you are awake. These two systems work together to regulate when you feel awake and when you feel tired.

What are our brains and bodies doing during different sleep stages?

During non-REM sleep, the body slows down for physical restoration, with heart rate, blood pressure, and breathing decreasing. During REM sleep, the body becomes more active, with increased heart rate and blood pressure, while the brain becomes highly active, leading to dreaming and temporary muscle paralysis.

Why do we sleep?

We sleep so our bodies and brains can repair, rest, and recharge, which is essential for overall health. During sleep, the brain processes information and consolidates memories, while the body repairs cells, conserves energy, and releases necessary hormones.

Why do we dream?

Freud - dreams stem from unconscious thoughts

Manifest content

the actual images in the dream

Latent content

the unconscious thoughts, feelings, andwishes behind the manifest content

Activation synthesis

brain's internally generated signalsform dreams

Information processing

memories of events form dreams

Preserving neural pathways

purpose of dreaming is toprovide brain stimulation

Circadian rhythm

biological clock (controlled by hypothalamus)-

- Provides approximate schedule for physical processes

Suprachiasmatic nucleus (SCN)

in hypothalamus -sensitive to changes in light• Controls pineal gland- Pineal gland - secretes melatonin• Melatonin - hormone that causes sleepiness

- controls the pineal gland

pineal gland

secretes melatonin

Melatonin

hormone that causes sleepiness

Circadian Rhythms

darkness & light

Darkness

SCN directs pineal gland to secrete melatonin

Light

SCN directs pineal gland to stop secretingmelatonin

Artificial lighting

interferes with circadian rhythm

types of sleep

1. Non-rapid eye movement (N-REM) - 3 stages

2. Rapid eye movement (REM) - brain waves resemble wakefulness

Sleep Stages

90-minute cycles of sleep stages

1. Non-rapid eye movement (N-REM) - 3 stages

N1

N2

N3

N1

light sleep- Hypnic or hypnagogic jerk- Hypnagogic hallucinations

N2

true sleep• Brain activity slows• Reductions in heart rate and muscle tension

N3

deep sleep• Further slowing of brain activity• Hard to awaken, disoriented when awakened• Growth hormones released from pituitary

Rapid eye movement (REM)

Eyes move back and forth- Heart rate, blood pressure, breathing - rapid or irregular- Sleep paralysis- "Paradoxical sleep"- Dreams

Sleep Cycle

Evolutionary/adaptive theory

protection - not outand vulnerable to predators in the dark

Restorative theory

sleep supports growth and healing- Production of growth hormone- Supports immune functioning

Sleep deprivation

slower healing, reduced immune system activity

impairment of memory formation

Information processing theory

sleep supports cognitive processes- Supports learning- Restores and rebuilds memories, Supports creative thinking

Effects of Sleep Deprivation

Irritability, mood disruption• Increased risk of depression• Increased risk of obesity