Human consciousness

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Human consciousness

• Domján Nóra
• 2009.

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Normal waking consciousness

• Stream of consciousness (we are aware of many
  external and internal stimuli at a time)
• We can deal only with a few stimulus (attetion
  mustnt be distracted)
• Which processes help in picking the important
  stimuli? ? focusing

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Subconscious mental activity

• Preconscious
• Can be brought into awareness
• Automatised activities, processes
• Unconscious
• Permanently unaviable for the consciousness
• Physiological functioning
• Processes of thinking and creativity
• Freudian slips

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Attention

• Consciousness is limited by the selective
  attention (can be effortful, directed)
• Cocktail party phenomenon dichotic listening
  (different infomation into each ear, one must be
  shadowed) ? only one source can be remembered
• Unattended information is also monitored, so it
  can influence behaviour (outstanding stimuli are
  understood)

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Priming

• Undecetable or unprocessed stimuli affect
  behaviour, task solving
• A stimulus below the treshold of awareness can
  accelerate the processing of a conscious
  stimulus, if they are related to each other in
  some way
• E. g. kitten ? xxx ? cat ? decision
• prime ? pause/mask ? (RT measured)

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• This filtering is automatic and involuntary
• In a complex environment attention can become
  effortful, but gets better with time and
  practicing
• In some situations automatic behaviour can be
  regarded as mindless (it results in an unwilled
  consequence, e. g. an accident)

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Sleep and dreams

• We spend almost one third of our lives with
  sleeping
• The first method to examine brain activity during
  sleep has been EEG (electroencephalogram)
• Sleep is a multifaceted, patterned and complex
  activity

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Stages of sleep

• Main difference dreams ? NREM and REM (Rapid Eye
  Movement) sleep
• During NREM phases
• Breathing becomes slow and even
• The heartbeat becomes regular
• Blood pressure falls
• Brain temperature decreases
• Blood flow to the brain is reduced
• Little or no body movement

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NREM stages

• Stage 1 (ten mins)
• Lightest level of sleep (rather dreamy, than
  dream), Low voltage, fast EEG, somewhat irregular
• Stage 2 (twenty mins)
• Sleep spindles appear, sleep deepens
• Stage 3
• Delta waves (high voltage, low-frequency), deep
  sleep begins
• Stage 4
• Deepest sleep, only slow delta activity

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REM sleep

• Heightened EEG and physiological arousal
• Paradoxical sleep
• Brain and internal organs are highly activated
• Motor neurons are inhibited, so that moving is
  impossible
• External stimuli are not percieved
• Dreaming
• Returns periodically

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A nights pattern
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Stages of awakeness on EEG
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The need to sleep

• Sleep deprivation
• Few days whithout sleeping does not cause serious
  decrease in biological functioning and cognitive
  performance
• Subjective reports are controversial to
  experimental evidence
• Circadian rhytm
• Biological clock (25 hours period)
• Evolutional roots
• Energy saving and restoring body tissues
• Safety

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Sleep disorders

• Insomnia
• Lenghty time to sleep onset
• Frequent wakening
• Early morning wakening
• Causes psychological disorders (anxiety), drugs
• Sleepwalking
• Mostly in childhood
• Narcolepsy
• Sleep attacks during the day
• Cataplexy, sleep paralysis, hypnogogic
  hallucinations
• Sleep apnea
• Cessation of breathing interrupts sleeping (10
  40 secs)

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Dreams

• Characteristics
• Mostly visual images
• Fantastic, irreal storyline
• Emotion provoking
• Delusional quality
• Dream-deprivation studies
• Subjects awakened at the beginning of REM
• On recovery nights REM phases occur more often
  and longer
• People need dreaming ? irritabilty

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Dream theories

• Freud
• Dreams as wish fulfillment
• Uncoscious wishes an be repressed when awake, if
  they are not tolerated
• Manifest (symbolic) and latent content of dreams
  ? dream analyses (interpretation)
• Hobson and McCarley
• Activation-synthesis hypothesis
• Random brain activation is synthetised by the
  cortex into dreams (by-product)

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Sleep and development

• Sleep may be needed for maturation of brain cells
  and consolidation of memories (by newborn 50 of
  sleep is REM)

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Altered states of mind

• Organic
• Sleep
• Psychosis
• Self-induced
• Meditation
• Hypnosis
• Chemical induction
• Psychoactive drugs

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Meditation

• Focusing on a single, simple image, phrase or
  sound reduces the awareness of other external or
  internal stimuli
• Psychological effects
• Calmness, well-being, which continues into the
  daily life
• Physiological effects
• Alpha waves dominate brain activity instead of
  betas
• Decreased breathing and heart rate (reduced
  arousal)
• Clinical application
• Therapy for stress-related disorders

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Hypnosis I.

• The suggestions of the hypnotist changes
  perception, memory and behaviour (at the extent,
  the subject allows)
• Hypnotic induction enhances this mental state
• Focused attetion
• Reduced reality testing
• Imaginative involvement
• Hypnotic suggestion
• Hallucinations (positive/negative)
• Memory (amnesia/hypermnesia)
• Behaviour (posthypnotic suggestions)

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Hypnosis II.

• Hypnotic susceptibility
• Trait (20 highly, 5-10 not at all)
• Can be measured through standardized procedures
• Clinical application
• Working with traumatic memories
• Leuners Guided Affective Imagery Therapy

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Psychoactive substances I.

• Sedatives
• Decrease activity levels, produce calmness
• Ethyl alcohol, barbiturates, benzodiazepines
• Sedation Intoxication Anesthesia Coma -
  Death
• Stimulants
• Increase activity levels, enhance positive
  feelings, heighten alertness ? euphoria
• Caffeine, amphetamines, cocaine (nicotine)
• Rebound ? depression ? repeated usage
• Can trigger psychosis

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Psychoactive substances II.

• Psychedelics
• Alternate perception, thought, imagination
• LSD, psylocibin, mescaline
• Hallucinations, depersonalisation, memories can
  return (therapy?)
• Miscellaneous
• Mixed sedative, psychedelic, or stimulant effects
• Cannabis sativa, PCP
• Narcotics
• Painkillers
• Opium, Morphine, Heroin
• Euphoria, drowsiness, nausea

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