Psychobiological Processes Flashcards
What is an electroencephalograph?
EEG. Measures brain activity (brain waves).
What is an electromyograph?
EMG. Measures muscle activity.
What is an electro-ocular graph?
EOG. Measures eye movement.
What are other measures of consciousness?
Heart rate and blood pressure, body temp., GSR (galvanic skin response), self-report, video monitoring.
Who discovered 2 types of sleep?
Azerinsky and Kleitman (1953) - EEG: NREM and REM sleep. 90 min cycles 5 per night.
Awareness
Awareness is reduced, however noises or sounds with personal relevance may wake someone.
Content limitations
Broader and deeper thoughts. Bizarre dreams with less restrictions.
Controlled and automatic processes
Unable to perform tasks, however somnambulists are an exception.
Perceptual and cognitive distortions
Attention to sensory stimuli is lowered as is pain. Thoughts are disorganised and unrealistic.
Memory
Although 2 hours of the night is spent dreaming, they cannot all be recalled.
Emotional awareness
Emotions are intensified either positively or negatively. Some evidence suggests that sleep helps to deal with emotions (Cartwright, 1998).
Self control
Maintaining self control and behaviour while sleeping is lowered resulting in snoring, dribbling, talking, grinding.
Time orientation
The speed at which time passes can move more slowly or quickly. People are able to estimate the amount of time passed whilst asleep (Tagaya et al, 2009).
What is consciousness?
“Subjective awareness of mental events” (Burton, 2009).
What is an ASC?
When changes in mental awareness occur to the extent that you can notice differences in your level of mental functioning, you have entered an altered state of consciousness (Glicksohn, 1991).
Partial sleep deprivation
The severity and extent of the side effects depend on the individual, the amount of sleep lost, and the period of time which the sleep deprivation occurs (Coren, 1996).
Effects of partial sleep deprivation
Cognitive (slower reaction time, problem solving decreases, motor skills), psychological (inability to concentrate, low motivation), physiological (lack of energy, interruption in growth process (hormones are released in NREM)).
Evidence of partial sleep deprivation
After 4 hours of sleep deprivation, reaction time is 45% slower on a perceptual motor task such as driving (Maas 1998).
Sleep debt
People everywhere are living less than an optimal life and level of functioning, impaired by an amount of sleep debt that they are unaware of (Dement, 1999).
Total sleep deprivation
Peter Tripp (Dement 1972) - 8 days awake for charity. Observed under strict conditions, mean body temperature decreased overtime, hallucinated during REM sleep. Behaviour and personality changed wife said.
Selective sleep deprivation
The body will spend more time in REM sleep next time in order to make up for their deprivation (Bonnet, 2005).
Circadian rhythm evidence
Many blind people report sleep problems as the absence of light disrupts their circadian rhythm (Czeisler et al, 1995)
Circadian rhythm and preference
Refers to a biological clock which regulates within 24-25 hours.
Wallace (1993) discovered that there is circadian preference
Sleep-wake cycle shift in adolescence
Hormonally induced shift of the body clock forward by 1 to 2 hours.
Restoration theory
Oswald (1966) maintains that sleep’s purpose is restorative. NREM restores bodily processes while REM replenishes brain functions.
REM repair evidence
Developing foetuses and infants spend more time in REM sleep than other life stages (Hockenbury and Hockenbury 2006).
Information reviewed during waking hours is more likely to be remembered after sleep (Gais et al, 2006).
The body will spend more time in REM sleep next time in order to make up for their deprivation (Bonnet, 2005).
NREM repair evidence
Many hormones and neurotransmitters that influence mood and emotion are active when we’re asleep (Boivin at al 1997).
Secretion of growth hormones is released during NREM (Pandi-Perumal et al, 2008).
Evaluation of restoration theory
Empson (1993)- NREM and REM sleep are responsible for different restorative capabilities however cell repair occurs 24 hours a day.
Survival theory
The adaptive theory suggests that sleep evolved because it prevented early humans and animals from wasting energy and exposing themselves to the dangers of nocturnal predators (Webb, 1992).
Evidence of survival theory
Many birds sleep with only one hemisphere at a time, to guard against predators (Sillery, 2002).
As humans rely on visual cues and lack night vision, circadian clock has evolved to allow for sleeping at night (Hirshkowitz et al, 1997).
Evaluation of survival theory
Cannot generalise animal studies to humans.
Psychoanalytic theory: Wish-fulfilment
Freud (1965)- dreams have meaning but must be translated by a dream interpreter.
Manifest content- the basic storyline of the dream.
Latent content- the dream’s underlying meaning- unconscious wish typically a sexual desire.
Dreams are forgotten as they contain anxiety-provoking thoughts usually repressed during NWC.
An interpreter’s task is to translate dream symbols and uncover a client’s unconscious desires (Bower, 2001).
Evaluation of Psychoanalytic theory
Unreliable as it is untestable. Subjective self-report and interpretations.
Extensions of Waking Life Theory
(Cartwright 1977)
Dreams reflect a person’s thoughts and fears experienced when in NWC.
Evidence of Waking Life Theory
Dreams serve a problem-solving capability presenting dreamers with solutions to problems being faced (Cartwright, 1996).
Dreams show cognitive development- children’s dreams lack the sophistication of adult dreams (Foulkes, 1982).
Activation Synthesis
(Hobson and McCarley 1970)
Dreaming occurs as areas of the brain which provide cognitive control are shut down. Cortex is highly active during REM sleep but receives little external stimulation.
Evidence of Activation Synthesis
Pre-frontal cortex responsible for problem-solving is less active while visual cortex and limbic systems (emotions) are highly active (Braun 1998).
Explains why dreams are emotional and full of imagery but are often bizarre and lack logic that differs from NWC (Domhoff, 2003).
Reverse learning
(Crick and Mitchison 1986)
We dream to get rid of useless or redundant information. An overload of information during NWC occurs and REM sleep is used to clean up and allow for new input.
