Chapter 8 | Wakefulness and Sleep (Learning Material)

References: Kalat, J. W. (2019). Biological psychology (13th ed., pp. 257–285). Cengage Learning. Roffwarg, H. P., Muzio, J. N., & Dement, W. C. (1966). Ontogenetic development of human sleep-dream cycle. Science, 152(3722), 604–609. https://doi.org/10.1126/science.152.3722.604

The body's natural 24-hour clock that regulates the sleep-wake cycle.

Circadian Rhythm

Rhythms that are generated internally, such as the circadian and circannual rhythms.

Endogenous Rhythms

A stimulus that resets the biological clock; German for "time-giver."

Zeitgeber

A cluster of neurons in the hypothalamus that regulates the circadian rhythms.

Suprachiasmatic Nucleus (SCN)

A hormone released by the pineal gland that regulates sleep-wake cycles.

Melatonin

A sleep disorder characterized by pauses in breathing or instances of shallow breathing during sleep.

Sleep Apnea

The most common sleep disorder, characterized by difficulty falling or staying asleep.

Insomnia

A sleep stage where most dreaming occurs, characterized by rapid eye movement and increased brain activity.

REM Sleep

A state where a person is aware they are dreaming while still asleep.

Lucid Dreaming

Intense episodes of fear during sleep, usually occurring during NREM sleep.

Night Terrors

A gland that secretes melatonin and helps regulate sleep patterns.

Pineal Gland

A state of being awake and alert, regulated by the reticular formation.

Arousal

Extended unconsciousness due to trauma or disease, with low brain activity.

Coma

A combination of EEG and eye-movement records used to track sleep stages.

Polysomnography

A neurotransmitter that inhibits neuron activity, playing a key role in promoting sleep.

GABA

A sleep disorder characterized by involuntary limb movement during sleep.

Periodic Limb Movement Disorder

A temporary inability to move or speak while falling asleep or waking up.

Sleep Paralysis

A theory that dreams result from the brain's attempt to make sense of random neural activity.

Activation-Synthesis Hypothesis

A theory that dreams are spontaneous thoughts occurring during reduced sensory input.

Neurocognitive Hypothesis

A prolonged state of dormancy that reduces metabolism and conserves energy.

Hibernation

burst of electrical activity that occurs during REM sleep and is linked to dream imagery. 

PGO (Post-Geniculate-Occipital waves)

 a condition characterized by frequent periods of sleepiness during the day. 

Narcolepsy

The hormone that regulates sleep/wake cycle, controls puberty onset, and affects seasonal changes.

Melatonin

It alternates between sleep and moderate arousal, no awareness or purposeful behavior, and autonomic responses.

Vegetative State

No brain activity or response to any stimulus, confirmed after 24 hours of no brain activity, ethical to remove life support after brain death is confirmed.

Brain Death

Measures brain electrical activity by recording potentials from cells and fibers near the scalp.

Electroencephalograph (EEG)

It is located between the pons and midbrain a part of the reticular formation that plays the central role of controlling alertness and arousal.

Pontomesencephalon

What cause is related to Narcolepsy?

Neurotransmitter Orexin

Does Periodic Limb Movement Disorder happen during REM or NREM sleep?

NREM Sleep

It’s when people apparently act on their dreams during their REM periods.

REM Behaviour Disorder

It’s a case of sleep disorder more severe than a nightmare.

Night Terrors

 An analogous condition of sleepwalking.

Sleep sex or sexsomnia

A part of the brain does learning experiences replay during sleep.

Hippocampus

A theory that sees dreams as thought-like activity influenced by memory, emotions, and visual imagery during sleep.

Neurocognitive hypothesis

A special pathway to give information about light to SCN from the retina.

Retinohypothalamic path

The two specific genes that control sleep-wake cycle.

Period (PER) and Timeless (TIM)

 A type of person who reaches their peak early and becomes less alert later in the day.

Morning Person or Lark

How do REM and NREM sleep change with age, and what is one theory about REM sleep’s function?

As people age, REM and the total sleep decrease, and one theory suggests that REM helps oxygenate the corneas by moving the eyes during sleep.

What explains why we dream of flying or being paralyzed during sleep based on brain activity patterns?

Random brainstem signals interpreted by the cortex.

Actively produced by the brain, Characterized by decreased activity and response to stimuli.

Sleep

What are some key functions of sleep?

Sleep helps rest muscles, lower metabolism, maintain neurons, reorganize synapses, and strengthen memories.

What is a likely original function of sleep across species?

A likely original function of sleep is energy conservation, especially during times when activity would be inefficient or dangerous.

How is hibernation similar to sleep, and what are some unique features of hibernation?

Hibernation, like sleep, conserves energy and involves lowered metabolism and brain activity. It also slows aging, increases lifespan, and offers protection against infection and injury.

Why do sleep patterns vary so much across animal species?

Sleep patterns vary based on species' needs for alertness, energy conservation, and feeding habits. Animals sleep less when constant activity or alertness is crucial, like during migration or after giving birth.

How do aquatic mammals like dolphins manage to sleep without drowning?

Dolphins sleep with one hemisphere of the brain at a time, allowing the other side to stay awake for breathing and swimming.

Why is sleep important in memory storage?

Lack of sleep will impair memory consolidation. Sleep will facilitate the transfer of memories

What explains why we dream of flying or being paralyzed during sleep based on brain activity patterns?

 Random brainstem signals interpreted by the cortex.

What theory sees dreams as thought-like activity influenced by memory, emotions, and visual imagery during sleep?

Neurocognitive hypothesis.