Module 6: Consciousness

Consciousness 

describes our awareness of internal and external stimuli.

Feeling pain, hunger, thirst, sleepiness, and being aware of our thoughts and emotions.

Awareness of internal stimuli includes [5]

seeing the light from the sun,

feeling the warmth of a room,

and hearing the voice of a friend.

Awareness of external stimuli includes experiences such as seeing the light from the sun, feeling the warmth of a room, and hearing the voice of a friend. [3]

continuum that ranges from full awareness to a deep sleep

We might even describe consciousness as a:

Sleep 

a state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness

Wakefulness

characterized by high levels of sensory awareness, thought, and behaviour

William James

wrote extensively about attention in the late 1800s

 limited capacity for information processing

means that we can only attend to or be consciously aware of a small amount of information at any given time.

the nature of the task used to study it.

we define different types of attention by

lag.

When watching for a rare event, it is easy to allow concentration to ___

 sustained attention or vigilance 

Attention in the context of this type of search task (staring and waiting for an event to happen) refers to

 divided attention

allow us to determine how well individuals can attend to many sources of information at once.

Spatial attention

 refers specifically to how we focus on one part of our environment and how we move attention to other locations in the environment.

selective attention

 the ability to select certain stimuli in the environment to process, while ignoring distracting information.

dichotic listening and shadowing tasks

experiements used to study selective attention

Dichotic listening

simply refers to the situation when two messages are presented simultaneously to an individual, with one message in each ear.

Biological rhythms

internal rhythms of biological activity.

Alertness is associated with higher body temperatures, and sleepiness with lower body temperatures.

body temp in relation to consciousness

circadian rhythm 

a biological rhythm that takes place over a period of about 24 hours.

hypothalamus

main centre for homeostasis

suprachiasmatic nucleus (SCN).

The brain’s clock mechanism is located in an area of the hypothalamus known as

The axons of light-sensitive neurones in the retina provide information to the SCN based on the amount of light present, allowing this internal clock to be synchronized with the outside world. When the retina in the eye is exposed to light, it then stimulates the SCN, which then prompts the pineal gland to decrease the amount of melatonin it secretes.

how does the brain’s clock work

Melatonin. increases drowsiness and relaxation

One important regulator of sleep-wake cycles is the hormone

pineal gland,

an endocrine structure located inside the brain that releases melatonin

release is stimulated by darkness and inhibited by light.

how is melatonin release stimulated

chronotype

individual differences in circadian patterns of activity are known as

Sleep regulation

refers to the brain’s control of switching between sleep and wakefulness as well as coordinating this cycle with the outside world.

Jet lag 

a collection of symptoms that results from the mismatch between our internal circadian cycles and our environment.

insomnia 

consistent difficulty in falling or staying asleep for at least three nights a week over a month’s time)

Rotating shift work

refers to a work schedule that changes from early to late on a daily or weekly basis.

sleep debt.

a person does not get sufficient sleep on a chronic basis

decreased levels of alertness and mental efficiency

The consequences of sleep debt include

7–9 hours

recommended sleep for adults

between 12 and 18 hours a night

recommended sleep for new borns

obesity, increased blood pressure, increased levels of stress hormones, and reduced immune functioning

sleep deprivation is associated with

24 hours, or following nights with fewer than four hours in bed.

that the most severe effects of sleep deprivation occur when a person stays awake for more than

hallucinate

if a person is awake for 48 hours, they could start to ______

meta-analysis

a study that combines the results of many related studies

1/3

how much of our lives are spent sleeping

sleep is distinguished by

low levels of physical activity and reduced sensory awareness

Sleep rebound

refers to the fact that a sleep-deprived individual will fall asleep more quickly during subsequent opportunities for sleep.

sleep rebound following sleep deprivation. 

Homeostatic regulation of sleep is evidenced by

certain patterns of activity of the brain that can be visualized using electroencephalography (EEG), and different phases of sleep can be differentiated using EEG as well.

Sleep is characterized by

thalamus,

the hypothalamus,

and the pons

Sleep-wake cycles seem to be controlled by multiple brain areas acting in conjunction with one another [3]

rapid eye movement (REM)

The pons is important for regulating _______________ sleep

FSH and LH

During sleep, the pituitary gland secretes both __________ which are important in regulating the reproductive system

growth hormone

The pituitary gland also secretes ________, during sleep, which plays a role in physical growth and maturation as well as other metabolic processes

Evolutionary psychology

a discipline that studies how universal patterns of behaviour and cognitive processes have evolved over time as a result of natural selection.

One hypothesis from this perspective might argue that sleep is essential to restore resources that are expended during the day

Evolutionary pschology hypothesis for why we sleep

Some research suggests that species that face higher predatory risks sleep fewer hours than other species

relationship between hours slept and predatory risk

include maintaining healthy weight, lowering stress levels, improving mood, and increasing motor coordination, as well as a number of benefits related to cognition and memory formation.

benefits of adequate sleep

using EEG and are distinguished from one another by both the frequency and amplitude of brain waves

How are changes in brain wave activity visualized

REM sleep and non-REM (NREM) sleep.

Sleep can be divided into two different general phases:

Rapid eye movement (REM)

sleep is characterized by darting movements of the eyes under closed eyelids. Fourth and final sleep stage

. Brain waves during REM sleep appear very similar to brain waves during wakefulness.

REM brain waves:

non-REM (NREM) 

sleep is subdivided into four stages distinguished from each other and from wakefulness by characteristic patterns of brain waves. The first three stages of sleep are this

Stage 1 sleep

a transitional phase that occurs between wakefulness and sleep, the period during which we drift off to sleep

During this time, there is a slowdown in both the rates of respiration and heartbeat. In addition, involves a marked decrease in both overall muscle tension and core body temperature.

what happens stage 1 sleep

alpha waves,

relatively low frequency (8–13Hz), high amplitude patterns of electrical activity (waves) that become synchronized

Theta waves 

even lower frequency (4–7 Hz), higher amplitude brain waves than alpha waves

 stage 2 sleep

stage of sleep where the body goes into a state of deep relaxation.

Theta waves still dominate the activity of the brain, but they are interrupted by brief bursts of activity known as sleep spindles

stage 2 sleep brain waves

A sleep spindle

a rapid burst of higher frequency brain waves that may be important for learning and memory

K-complex  (stage 2 sleep)

a very high amplitude pattern of brain activity that may in some cases occur in response to environmental stimuli.

Stage 3 sleep

often referred to as deep sleep or slow-wave sleep because this stage is characterized by low frequency (less than 3 Hz), high amplitude delta waves

of this combination of high brain activity and lack of muscle tone

REM sleep is often referred to as paradoxical sleep because

The REM rebound,

If people are deprived of REM sleep and then allowed to sleep without disturbance, they will spend more time in REM sleep in what would appear to be an effort to recoup the lost time in REM

REM sleep is homeostatically regulated

the rem rebound suggests that

REM rebound may actually represent an adaptive response to stress in nondepressed individuals by suppressing the emotional salience of aversive events that occurred in wakefulness

Role of REM sleep in emotional processing and regulation

Manifest content

the actual content, or storyline, of a dream.

Latent content

refers to the hidden meaning of a dream.

Swiss psychiatrist Carl Jung

believed that dreams allowed us to tap into the collective unconscious.

collective unconscious,

a theoretical repository of information he believed to be shared by everyone.

Rosalind Cartwright

this researcher’s ideas about dreaming have found empirical support.

Alan Hobson

credited for developing activation-synthesis theory of dreaming.

activation-synthesis theory of dreaming.

this theory proposed that dreams were not the meaning-filled representations of angst proposed by Freud and others, but were rather the result of our brain attempting to make sense of ("synthesize") the neural activity ("activation") that was happening during REM sleep.

 Lucid dreams 

dreams in which certain aspects of wakefulness are maintained during a dream state. a person becomes aware of the fact that they are dreaming, and as such, they can control the dream’s content

Insomnia

the most common of the sleep disorders.

involves experiencing these symptoms (wake up several times during the night only to find that they have difficulty getting back to sleep, long delays between the times that they go to bed and actually fall asleep) for at least three nights a week for at least one month’s time

criteria for insomnia

overtired and may be associated with symptoms of depression.

Chronic insomnia is almost always associated with feeling:

might limit their use of stimulant drugs (such as caffeine) or

increase their amount of physical exercise during the day.

might turn to over-the-counter (OTC) or prescribed sleep medications to help them sleep (sparingly to not be dependent)

insomnia treatment

 Cognitive-behavioural therapy 

a type of psychotherapy that focuses on cognitive processes and problem behaviours.

The treatment of insomnia likely would include stress management techniques and changes in problematic behaviours that could contribute to insomnia

cognitive behavioural therapy for insomnia:

• going to bed and waking up at the same time every day

• Avoid anything stimulating for an hour before bed

• Exercise daily.

• Avoid naps.

• r bedroom temperature between 60 and 67 degrees.

• Avoid alcohol, cigarettes, caffeine, and heavy meals before bed.

• If you cannot fall asleep, leave your bed and do something else until you feel tired again.

tips to maintain healthy sleep:

parasomnia 

one of a group of sleep disorders in which unwanted, disruptive motor activity and/or experiences during sleep play a role.

Sleepwalking, restless leg syndrome, and night terrors

examples of parasomnias [3]

sleepwalking, or somnambulism

the sleeper engages in relatively complex behaviours ranging from wandering about to driving an automobile. sleepers often have their eyes open, but they are not responsive to attempts to communicate with them.

most often occurs during slow-wave sleep, but it can occur at any time during a sleep period in some affected individuals

when does sleepwalking occur

treated with a variety of pharmacotherapies ranging from benzodiazepines to antidepressants. However, the success rate of such treatments is questionable.

Treat breathing problems

how to treat sleepwalking

REM sleep behaviour disorder (RBD) 

occurs when the muscle paralysis associated with the REM sleep phase does not occur. Individuals who suffer from RBD have high levels of physical activity during REM sleep, especially during disturbing dreams.

These behaviours vary widely, but they can include kicking, punching, scratching, yelling, and behaving like an animal that has been frightened or attacked.

RBD symptoms

Clonazepam, an anti-anxiety medication with sedative properties. As part of treatment, the sleeping environment is often modified to make it a safer place for those suffering from RBD

RBD treatment

restless leg syndrome

uncomfortable sensations in the legs during periods of inactivity or when trying to fall asleep.

relieved by deliberately moving the legs, which, not surprisingly, contributes to difficulty in falling or staying asleep.

How is restless leg syndrome discomfort relieved?

chronic kidney disease and diabetes

restless leg is associated with what other diseases?

benzodiazepines, opiates, and anticonvulsants

Drugs that treat restless leg

Night terrors 

 result in a sense of panic in the sufferer and are often accompanied by screams and attempts to escape from the immediate environment.