Consciousness Flashcards
Levels of consciousness
Conscious,
Pre-conscious,
Non-conscious,
Sub-conscious/unconscious
Why do we have consciousness?
Construct of the sensory world more accurate
Behavioural responses are enhance and more appropriate
Consciousness allows us to plan/regulate thoughts
What is attention?
“Process of focusing conscious awareness, providing heightened sensitivity to a limited range of experience requiring more extensive information processing”.
Is attention voluntary or involuntary?
Both. Attention can be voluntarily controlled (top-down processing) or involuntary (bottom-up processing).
How are attention and perception linked?
Conscious perception requires attention, but in order to allocate attention, a lot of implicit processing is occurring outside of awareness
What information is processed out of conscious awareness?
Shift in attention Automatic tasks Priming Subliminal perception Reconstruction of memory First impressions
Cork, Kihlstrom and Hameroff 1992 study
People under general anaesthetic presented with 15 word pairs repeatedly
Afterwards couldn’t remember being presented with any words but if they were given first word, they could complete the pair.
What are subliminal stimuli?
Sensory stimuli below the threshold for conscious perception. They are attended to by the brain, but not consciously perceived
How do subliminal stimuli affect the brain?
fMRI studies show that subliminal studies activate specific cortical regions despite participants being unaware.
What are different states of consciousness?
Awake Hypnosis Daydreaming Sensory deprivation Orgasm Food/oxygen starvation Dreaming Asleep Hallucinating Meditation
What are hallucinations?
Realistic perceptual experiences created in the absence of external stimuli.
Usually visual but can be in any form (olfactory, gustatory, tactile)
What is déjà-vu?
Sense that you have experienced something previously and/or predict what is going to happen
Neuropsychology suggests it is caused by small seizures in right temporal lobe associated with feelings of familiarity
What is capgras syndrome?
Disorder in which a person believes that a friend/family member replaced by imposter. Can by caused by schizophrenia, dementia, brain injury, etc.
Origin is a disconnection between temporal lobe (facial recognition) and the limbic system (emotions)
What is sleep?
A heightened anabolic state which build and accentuates the development of the immune system, nervous system and muscular and skeletal systems
What is the circadian rhythm?
An inner time-keeper, temperate regular, enzyme-release controller that works alongside neurotransmitters.
It determines optimal timing of a correctly structured and potentially restorative sleep.
What is the function of sleep?
Many functions unknown but: immune system maintenance growth neuronal maintenance cognitive functioning motor control
What are some symptoms of sleep deprivation?
Cognitive impairment Memory lapses Impaired moral judgment Hallucinations ADHD symptoms Impaired immune system Increase reaction time and decrease accuracy Growth suppression Psychological disorders
How many stages of sleep are there?
Four non-REM stages and one final stage being REM
Describe stage 1
Transition stage from wake to sleep Very brief Fantastical images reported - hallucinations Falling or floating sensations No memory of this stage
Describe stage 2
Occupies about 45-55% of total sleep
Characterised by bursts of brain activity following a muscle twitch
Characterised by k-complexes - a brief negative high voltage peak of activity
Lasts about 20 minutes
Reflects deeper relaxation, but still a light sleep
Describe stage 3
Transition to deep sleep
Characterised by the presence of delta brain waves
Stage in which parasomnias occur - night terrors, sleep walking, bedwetting, sleep talking
Lasts a few minutes
Describe stage 4
Deep sleep - hard to awaken
Likely involved in muscle/body restoration
Similar to stage 3, but more delta waves
As you age, the amount of stage 4 sleep decreases
At the end of stage 4, don’t go straight to REM - we ascend back up to stages 3 and 2 then jump to REM
Describe REM sleep (stage 5)
Final stage
20-25% of total sleep time
Characterised by rapid eye movements and rapid low voltage EEG
Most memorable dreaming occurs
Descending muscular atonia - paralysis that protects from self harm
Which stage is considered to be the most important?
REM. REM deprivation can caused anxiety, irritability, increased appetite.
What is dreaming?
Sequence of images, emotions and thoughts in which dreamer is usually a participant and not an observer
Stimulated by the pons
Can incorporate external sleep environment
What is Freud’s theory on why we dream?
Wish fulfilment
- unacceptable feelings
- erotic wishes/violent urges
- safe environment to deal with socially unacceptable desires
- manifest content
- latent content (expert required to uncover meaning in latent content)
What is the activation-synthesis hypothesis?
Dreams are a meaningless by-product of a neurobiological process
The same structures that induce REM sleep also generate sensory information
Solms suggests that dreams are generated in the forebrain, not the brainstem
Suggests REM sleep and dreaming are not directly related
Dreaming is similar to wakeful consciousness & we construct images to make sense of neuronal firing
