Sleep and Dreaming Flashcards
What is the meaning of Consciousness?
It is the awareness of objects and events in the external world and our sensations, mental experiences and existence at any given moment.
What does Normal Waking Consciousness mean?
It is our awareness of internal states and external surroundings when we are awake and unaffected by sleep, drugs or other states.
What does Altered State of Consciousness mean?
It is anything that is not normal waking consciousness.
What is conscious experience associated with?
The activity of neurons in the brain.
What are four characteristics of consciousness?
- Personal (individual)
- Selective (choose what we think about)
- Continuous
- Changing
List the states of consciousness from most aware to least aware
-Total awareness
-Focused, selective attention (controlled processes)
-Daydreaming
-Meditative state
-Hypnotized
-Asleep
-Anaesthetised
-Unconscious (coma)
-Complete lack of awareness
What are the three characteristics of NWC?
-Attention (Selective and divided)
-Controlled vs automatic processes
-Content limitation
What does attention mean?
A concentration of mental activity that involves focusing on specific stimuli and ignoring other stimuli
Where can attention be focused in NWC?
-Can be focused internally or externally
-Can be selective or divided
What does selective attention mean? and an eg
Attending to certain stimuli while ignoring other stimuli
e.g pickpocketing
What are some factors that influence attention?
-If stimuli is personally important to you
-Changes in stimulation
-Novel stimuli (something new)
What does divided attention mean?
The ability to distribute one’s attention and undertake more than one activity at the same time.
What do Controlled processes mean?
When information processing requires conscious, alert awareness and mental effort.
What are some characteristics of Controlled processes?
-Focused on achieving a particular goal
-Associated with a difficult or unfamiliar task
-Involves serial processing (one thing then another)
e.g driving a car
What do Automatic processes mean?
When information processing involves little conscious awareness and mental effort
What are some characteristics of Automatic processes?
-Easy of familiar tasks
-Involves parallel processing (two things at one)
e.g singing while cleaning
What does Content Limitations in NWC mean?
Content refers to the type of information held in consciousness. ROLLOC; The type of info in NWC when compared to content in ASC is more restricted, more organized, more limited, more logical, more ordered and more controlled
What are some other characteristics of NWC?
-Perception is clear
-Memory; ability to store and retrieve info
-Time orientation
-Ability to process internal and external info
How are processing and consciousness related?
The LOWER the level of processing, the LOWER the level of consciousness
Define sleep
A reversible behavioral state of perceptual disengagement from and unresponsiveness to the environment
What does reversibility mean in reference to sleep?
You can be woken up
What does perceptual disengagement mean in reference to sleep?
It means that the sleeper has no awareness of sensory stimuli and is typically unresponsive to stimuli
What does the SCN stand for?
Suprachiasmatic Nucleus
Where is the SCN located?
It is a tiny region of the brain in the hypothalamus. It is directly above the optic chiasm.
What is the optic chiasm?
It is a crossover of the two optic nerves
What does the SCN do?
It is responsible for controlling circadian rhythms. It detects the amount of light being sent to the brain for processing and then uses this info to influence amount of melatonin being released into the bloodstream. It is responsible for the ONSET of sleep.
What does circadian rhythms mean?
These are the sleep wake cycles that occur approximately every 24 hours.
What is Melatonin?
It is a hormone that is produced and secreted from the pineal gland and is associated with the sleep wake cycle.
What is the pineal gland?
It is a gland at the base of the brain which keeps track of the body’s natural cycles and registers external factors such as light an darkness.
What is the role of melatonin?
The more the light, the less melatonin is released. High levels of melatonin lead to sleepiness. Melatonin gradually builds up during the day.
Name the flowchart of how the SCN influences melatonin release?
LIGHT > EYES > SCN > PINEAL GLAND > MELATONIN RELEASE
What is the RAS?
Reticular Activating System. It is a network of neurons that extends out from the reticular formation to different parts of the brain and spinal cord.
What is the major purpose of the RAS?
Regulate cortical arousal. When we’re sleeping, we’re in a low cortical arousal, so the role of the RAS in sleep is to MAINTAIN the sleep state.
What are the major parts of the RAS?
-Reticular formation
-Thalamus
What is the Reticular Formation?
It is a structure running through the brain stem and up into the mid brain. It is critical in reducing stimuli that is sent to the cerebral cortex.
When RF stimulated = alertness
When RF damaged = coma
What is the role of the thalamus?
Acts as a sensory ‘way-station’ and filter for the rest of the brain.
What happens if there is damage to the thalamus?
-May cause loss of any sense (except smell)
-Attention difficulties (what to ignore and what to attend to)
-Lower arousal from lethargy to coma
What are the 3 methods to study sleep?
- Electroencephalograph
- Electromyograoh
- Electrooculogram
What does the EEG do?
It is a device used to detect, amplify and record electrical activity that is generated by the brain.
Explain the difference between Amplitude and Frequency in relation to brain waves
Amplitude; Refers to the intensity of the wave and is measured in wave height.
Frequency; Relates to how many occurs over time and is measured by how close the waves are to one another.
What is the acronym to remember the types of brainwaves?
‘Batman Ate The Donut’
List the types of brainwaves in order of most aware to least aware
Beta waves
Alpha waves
Theta waves
Delta waves