PSYC1002 #2 Flashcards
From middle of sleep lecture just before the start of behaviour
What does the suprachiasmatic nucleus control and do? How long does the human clock go for and how does the clock work?
Are sleep and wakefulness cycles affected by light?
Controls release of hormone melatonin from pineal gland
o Its activity acts as a clock and keeps track of the time of day tells body what time it is
o In humans, this clock goes for a total of 25 hours it is a bit slow but when light hits your face it resets
o Takes a few days for the clock to be reset properly easier to set your clock later than earlier so it’s easier to get over jetlag from a western country than from an eastern country
o Sleep and wakefulness cycles are not affected by lack of light
What does melatonin do and signal? When do levels of melatonin in blood peak? What is the difference in melatonin between young adults and old people?
• Melatonin signals night time to whole body
o Levels of melatonin level in blood from 12pm-6pm are flat but peaks at 12am and then goes back down in the morning
o The rise in melatonin is a cue for the brain to be going to sleep
o Young adults release more melatonin during the evening than older people
What does adenosine do when we’re awake
Builds up in brain
-Being awake for longer increases amount of adenosine
o Adenosine increases sleepiness (sleep pressure desire to go to sleep based on how long you’ve been awake) by inhibiting alertness centres (especially Ach in pons) and stimulating sleep centres (pre-optic area)
o Brain uses accumulation of adenosine level as an indicator of how long the person has been awake for
How is adenosine produced?
by brain as by-product of activities
How do you get rid of adenosine?
Through sleep
What does caffeine do?
Blocks adenosine receptors
What happens during an all-nighter
o An all-nighter means that melatonin levels go back down in the morning, but adenosine levels keep accumulating so feel less tired in the morning of an all-nighter but deadly tired the next night
Where is the pre-optic area?
In the anterior hypothalamus
What does destruction of the pre-optic area do?
Cause insomnia
What does stimulation of the pre-optic area do?
Induce sleep
What neurotransmitter do neurons in the pre-optic area contain and what does it do?
GABA- this neurostransmitter inhibits Ach, 5HT and NA arousal systems in brainstem so that you can go to sleep
How do you measure activity when someone is asleep?
EEG
What is the electrical activity in our brains when we’re awake?
• When we’re awake, the electrical activity in our brains is of high frequency but with small fluctuations
How is sleep characterised, and how is it achieved?
• Sleep is characterised by slow rhythmic patterns of electrical activity in the brain (slow-wave sleep, the 4th cycle of sleep).
o Activity slows down but fluctuations in electrical activity get larger and slower
Neurons around cortex are being synchronised
Synchronisation of neurons is achieved by the thalamus
• Thalamus can coordinate unification of brain as it is bidirectionally connected to the cortex can communicate with the cortex and cortex can communicate to it
What is Rapid Eye Movement sleep?
o At multiple times through the night, the brain waves become desynchronised, just like when we’re awake
o During these periods, the eyes dart back and forth
What happens if woken during REM
o If woken during REM, typically report dreams- associated with visual dreams
More dreams during REM than other cycles
What is REM caused by?
o REM sleep caused by neurons in Pons that contain acetylcholine and stimulate neurons in the thalamus, which project to the visual cortex
Using fMRI- during REM, various areas become very active: visual regions at back of brain, motor regions, and limbic system (especially amygdala and cingulate, the emotional parts (which is why our dreams are so emotional), even more active than when we’re awake)
Suppression of particular regions of frontal lobes (lateral prefrontal cortex; important for logic, reasoning and self control)- which is why you have no self-control in dreams and do things you normally wouldn’t do in dreams
Can we move during REM sleep? Why/why not?
o During REM sleep, we are paralysed
Ach neurons in pons stimulate neurons in medulla, which ultimately inhibit motor neurons in the spinal cord (paralysis)
Destruction of these neurons in medulla causes animal to become very active during REM sleep (no longer paralysed)
Motor signals to your eyes only thing that isn’t paralysed during REM sleep
This is why sometimes paralysed for 30 seconds in morning- REM sleep has yet to be turned off
Describe typical sleep cycle
- First few hours of sleep is deep slow wave sleep
* After 40min-1h, REM sleep may have a cycle- REM occurs more frequently in the morning
Does REM increase during the night and life span?
What does alcohol do to REM sleep?
- Amount of REM increases during the night, but decreases across life span (The foetus has a lot of REM: 50% for newborns, decreasing to 20% in adults.)
- Alcohol reduces REM sleep (including in utero)
Why is a reward useful?
o Motivation to engage in a particular behaviour o Animals (including humans) will act in order to receive some reward
What did Olds and Milner do?
o Electrical self-stimulation of the brain
Olds and Milner accidently implanted an electrode into the medial forebrain bundle ( a bundle of noradrenaline and dopamine fibres travelling from brainstem to forebrain)
Their rat kept returning to place where it had received electrical brain stimulation
O and M went on to show that rats with electrode in mfb would readily learn to perform many acts in order to receive electrical stimulation
If allowed, rats would do nothing else but press bar
• Would prefer to starve or even tolerate shocks through floor in order to continue self-stimulating
• The simulation has become an addiction
What axons are involved in rewarding effect? What drugs influence it and how?
• Dopamine axons in mfb make greatest contribution to rewarding effect of electrical stimulation
o Effects greatly reduced by destruction of dopamine fibres
o Many addictive drugs (e.g. amphetamines, cocaine) directly boost release of dopamine in mfb
o Other drugs (eg heroin) indirectly increase dopamine release
Rats will work (e.g. bar press) in order to receive injections of amphetamines or opiates into nucleus accumbens
o VTA- full of opium receptors which heroin and morphine directly influence
o Food and sex operate on this structure of the brain
Are the right and left hemispheres responsible for their respective sides or opposite sides?
Opposite sides- right hemisphere receives from left side of body whilst left hemisphere receives from right side of body
What does lateralised mean?
One side of brain is doing most of the work for something
Are the 2 hemispheres lateralised?
Yes
What evidence is there for lateralisation?
o Most of us have a hand-preference, indicating superiority of one hemisphere for manual control
Brain determines handiness -> for those with a right hand preference, left hemisphere does a better job for the fine control of the hand
Hand preference not specific to humans but hand preference split, while humans prefer to be right handed
o Of all cognitive or behavioural functions, language is the most lateralised
For most of us, the left hemisphere controls speech and is better at comprehension
In more than 95% of people who are right handed and 70% of left handed people, left hemisphere is better at controlling speech and comprehension
The evidence for this:
• Stroke (blocked blood brain vessel which causes surrounding tissue to die due to lack of essentials) in left (but not right) brain often causes aphasia (problems with production and comprehension of speech
• Brain imaging: left hemisphere is more active when person speaks or listens to speech
• Dichotic listening task- people understand a word faster if presented to right ear
Where is Broca’s area?
Lower posterior region of left frontal lobe
What does damage to Broca’s area do?
o Damage to Broca’s area causes difficulties speaking (expressive aphasia or non-fluent aphasia) but generally can understand speech
They can, however, articulate
o Broca’s aphasia is not just motor problem, because often those affected can sing
o There are problems with writing but not drawing
o Deaf signers with damage to Broca’s area can lose the ability to sign
o People with damage to Broca’s area know they have been affected and what they can’t do that they previously could
Where is Wernicke’s area?
Posterior region of left temporal lobe
What does damage to Wernicke’s area cause?
o Damage to Wernicke’s area causes problems with comprehension of speech (“receptive aphasia”)
o Produces fluent but meaningless speech (“fluent aphasia”)
Content of the speech is the problem -> patterns of speech perfect but content makes no sense (gibberish)
o Cannot read
o Not aware they have a problem -> don’t know what they’re missing that they could do before
Why do some people have callosotomy? (surgery to cut the corpus callosum)
• But some patients with intractable epilepsy had surgery to cut the corpus callosum (callosotomy)
o Split brain patients
o Epilepsy- electrical storm neuron activity spreads and takes over the brain
By cutting the corpus collosum, it can’t go to both hemispheres and it is contained in one hemisphere
Limits how long the attack lasts for as it can’t go back and forth hemispheres
Who extensively studied split brain patients?
Roger Sperry
What can split brain patients generally do?
- Split brain patients can still walk, talk, suffer little or no impairments of intelligence of emotion
- But some did report some disquieting difference between what left and right hands did (a woman’s left and right hand kept taking different clothes from each other -> each hemisphere had a different idea to what she should wear)
What two experiments did Sperry perform and what did he find?
o Sperry found that patient could name an object put in his/her right hand, but not object put in left hand
Sperry put a curtain over patients’ hands
Sperry would place object in each hand
If he put the object in the right hand, the person could recognise what it was
• This is because information from the right hand goes to the left hemisphere, that is lateralised for language, and therefore could express what was in the hand
• However, information from left hand goes to right hemisphere, which cannot speak: knew what was in the hand but couldn’t say it, so the left hemisphere had to guess wildly
• One of the patients had a comb placed in her left hand -> right hemisphere grew frustrated with lack of communication and brushed the thumb against the comb to make a sound to inform the left brain of what it is
o Experiment was done with vision-
A spot was focused on the screen
A different word was flashed on the left and right side of the screen
Patient could name word on right but not on the left
However, if 2 words flashed on screen and patients were asked to find the objects corresponding to the words, the left hand selects the object matching the left word, and the right hand selects objects matching the right word
• Hence, demonstrates that right hand knows -> just cannot communicate through language
What can the right hemisphere do?
• Right brain can comprehend simple language (but less so than left brain), but cannot produce speech
• The right brain contributes more than left to adding and interpreting emotional content in speech (sarcasm)
o Understands emotional content of language
o People with right brain damage had trouble understanding sarcasm
• Right brain better at producing and interpreting emotion in general
o Left side of the face produces more emotion than right side of the face
Who is Henry Molaison and what happened to him?
o H.M had a bike accident, smashed his head and got a concussion. His brain damage led him to contract epilepsy, that got worse as he aged
The scar tissue probably facilitated the development of the epilepsy
Epilepsy gets worse with age as brain starts to shift pathways to make it easier for epilepsy to attack
o Received brain surgery to treat at intractable epilepsy at 26 years old
o The surgeon removed hippocampus on both sides (+ the amygdalae and some of the surrounding cortex)
The surgeon decided the hippocampus was the likely cause of the epilepsy (area around the hippocampus temporal lobe is a very common starting point forseizures)
o The surgery worked as treatment for epilepsy, but rendered HM unable to learn and remember new information (dense amnesia)
Who is Brenda Milner and what did she do?
o Brenda Milner studied HM for many years
o HM’s older memories, acquired before the lesion, were spared
o Brenda Milner gave HM a mirror drawing task
Bit of paper on the table, which is blocked from view by an upstanding piece of paper -> the subject can only see their hands and the paper through a mirror
Hard to do at first but after a while gets easy
Despite not remembering having done the task, HM got better and better at it -> he learned how to do it
What does damage to the hippocampus do?
• Now shown in many patients that damage to the hippocampus causes severe anterograde amnesia (can remember old stuff but can’t learn anything new)
• Deficit only in creating new long-term memories, as patients with hippocampal damage can retain new information in short-term memory hippocampus is not where the memories are stored, the hippocampus acts as a transit
• Deficit specific to declarative learning and memory
o Patients show normal procedural learning, even though they can’t recall having done the task before
What is Wernicke-Korsakoff’s syndrome?
-Amnesia is not only due to brain damage but also diseases
What is Wernicke-Korsakoff’s syndrome caused by?
• Severe deficiency in vitamin B1 (thiamine) in chronic alcoholics (alcohol interferes with B1 absorption) triggers Wernicke Encephalopathy (confusion and disordered gait and eye movements)
o Can trigger panic in the brain: the brain has episode because part of the brain is dying
• Untreated, WE leads to Korsakoff’s psychosis, characterised by profound anterograde amnesia and some retrograde amnesia (which would result in confabulation)
o This means can lead to being unable to form new memories and the loss of some memories that occurred in the past
o This leads to confabulation: making things up to get a complete image (not lying intentionally)
• Amnesia due to irreversible damage to mammillary bodies (which are part of the hypothalamus) and part of the thalamus.
What is Alzheimer’s disease and what is it caused by?
• Progressive degenerative disease is characterised by:
o Loss of newly learned information, followed by loss of distant memories, factual knowledge and finally procedural skills
o Widespread neuro degeneration in brain
The brain shrinks, and sulci and ventricles enlarge
o Seems to target areas of temporal lobe around hippocampus, where the degeneration seems to start, and it then becomes spread out
o The cortex thins: the brain tissue deteriorates
o Abnormal neural tissue present in brain, especially prevalent in cortex and hippocampus
Senile plaques neurons are dying
Neuro-fibrillary tangles protein overproduction chokes neurons to death
What is the automatic/ implicit process theory of behavior?
- Low effort
- High capacity
- Rapid
- Default
- Associative
- Contextualised
- Nonverbal
- Evolutionarily old
- Modular
- No need of working memory
- Parallel
What is the controlled/explicit process theory of behaviour?
- High effort
- Low capacity
- Slower
- Inhibitory
- Rule-based
- Abstract
- Verbalisable
- Evolutionary modern
- Fluid
- Limited by working memory
- Serial
What is causality?
We see causal sequences but the sequences are all we actually perceive
What are categories of understanding?
As we experience sensory inputs, we must bring with us certain concepts, such as causality, by which we interpret and organize the inputs from the sensory world
What did Kant theorise?
- There are concepts in our minds that sensory input does not account for
- Causality-
- Causality is supplied by the observer
- Categories of understanding
- Not derived from experience
- We know, without being taught, that there are right and wrong actions, and we know that we ought to do the one and avid the other.
What are reflexes?
- Automatic and usually very fast: learning is not required
What are some examples of reflexes?
- Airpuff -> eye blink
- Food -> salivation
- Knee tap -> knee jerk
- Babinski reflex: touch a baby’s cheek -> head turn
- Startle reflex
What is the reflex arc?
- Reflex switches itself on
- Feedback system built into response
- Sensory afferents fire at different rates depending on the intensity of the stimulus
- If this rate exceeds a threshold, a response is elicited
- Activating a response pulls the arm away from the stimulus
- Pulling the arm away reduces the stimulation of primary afferents
- Reducing the input signal reduces stimulation of afferents
- A reduction in efferent stimulation reduces response strength
Are reflexes self-governing or not?
They are self-governing
What is an instinct, as defined by Darwin?
- Action which enables us to perform without knowing for what purpose
- Born with it
- Doesn’t require learning
What is Darwin’s theory of evolution?
• Animals had to have the structural and behavioural characteristics required to survive and to breed within their habitats
• Those that lacked these requirements left no descendants
• And living animals today are the descendants of those that possessed these requirements
• There are three key ideas to his theory of evolutio
• Variability:
o Within a species, animals vary one from another
• Heritability:
o Animals pass on their inherited characteristics to their offspring
• Selection:
o Variation means that some members of the species are better adapted than others to the ecology in which they live
• Those that are well adapted are more likely to have offspring, to which they will pass on their characteristics
• Those that are poorly adapted will have fewer offspring, and so their characteristics will diminish over successive generations
• This is known as selection pressure by the environment in which species lives
What is the system involved in shifting thresholds in the mind, and what is the relationship between emotions and pain sensitivity?
• Sensory (afferent) nerves detect stimuli as per normal
• Projection from brain inhibits transmission
• Motor (efferent) nerves stimulate muscles as per normal
• Emotions affect pain sensitivity:
o Aggression and fear would reduce pain sensitivity
o The placebo effect can reduce or heighten pain sensitivity
What is the difference between behaviorist and contemporary views on behaviour?
Behaviourism-
Theories of behaviour need only refer to changes in ability of stimuli to elicit responses
Contemporary views-
Behaviour can also be modulated by cognitive processes and emotions
How did James define instincts?
instincts are a complex unlearned response to a characteristic stimulus, which may also be complex
Are instincts stereotyped or not stereotyped?
Stereotyped
What are instincts also called?
Fixed Action Patterns
Are instincts dependent or independent of immediate external control?
Independent of immediate external control
What happens once a fixed action pattern is triggered?
Once triggered, a FAP continues to completion regardless of changes in the environment
What is a fixed action pattern triggered by?
Releasing stimulus
What are fixed action patterns associated with?
Associated with a specific source of energy and require an appropriate motivational state
Can fixed action patterns occur spontaneously?
Yes
when motivational state is high enough, a FAP can occur in the absence of any releasing stimulus
Can fixed action patterns be easily modified by learning?
No
What is the difference in muscular terms between fixed action patterns and reflexes
Fixed action patterns require multiple action groups whilst reflexes only require one
What is action specific energy?
the specific source of energy associated with a FAP, the level of which controls the intensity with which the FAP is performed or its sensitivity to the occurrence of releasing stimuli.
What is supernormal stimulus?
Stimulus that triggers a FAP more than an actual real life stimulus. E.g. red fire truck to real male stickleback
What is Freud’s psychoanalytic theory?
- Tripartite model of the mind
- The Id, the Ego, the Super Ego
- The life and death drives
- -Libido or Eros
- –Survival, hunger, thirst
- -Thanatos
- –Reducing tension
- Unconscious motivation- we are powerfully affected by thoughts, wishes and memories of which we have no conscious awareness
Who was Anna O?
Patient-
o Showed that the hysteria symptoms were actually associated with life events and the emotions that went with these events even though the patient could not remember the events
o The symptoms were relieved when the events were remembered and the emotions expressed
o Suggested that symptoms were caused by the energies of pent-up unconscious emotions, and would go away when the emotions were released
What is free association and Freud’s interpretation of it?
• Free association-
o Procedure that requires patient to talk freely, without censorship or attempt to direct the flow of thought
o By letting thoughts follow one another freely, a patient could show the therapist what associative bonds there were, and just what was linked with what in the patient’s mind
• Freud- Neurotic symptoms, dreams, slips of the tongue, and the like are disguised or symbolic expressions of wishes
o Wishes highly threatening to the patient and too threatening even to be allowed into consciousness
o Occurs when unacceptable impulses threaten to overwhelm the ego’s defences and explode into consciousness or action
What is unconscious conflict?
unconscious wishes are pushing to be expressed, but at the same time, another part of the patient’s mind is resisting any such expression
What happens to infantile urges?
• The persistence of infantile urges into adult thought and action-
o If urges are inhibited, they won’t just go away
o If denied direct expression, they will seek expression is some other way
o Hence the expression of the urge in symbolic form
What are sex and aggression affected by? Are they homeostatic motives? Does the role of learning affect them?
- Sex and aggression are affected by internal and external factors that interact
- Sex and aggression are not homeostatic motives
- The role of learning affects sex and aggression, especially in humans
Who were Lorenz and Tinbergen?
Ethologists
What did Lorenz do with imprinting?
• Just after they’ve hatched, when they see something, they think it’s their mother
• Imprinting happens after a day or 2 of hatching
• Instincts come about at particular biological phases
-Experimented this with geese
What are conditions of the fixed action pattern?
• The fixed action pattern
o The behaviour is stereotyped and constant in form
o It be characteristic of the species
o It appears in animals which have been raised in isolation from others
o It develops fully-formed in animals which have been prevented from practicing it
o It is made regardless of the consequence
o Once triggered, the entire sequence of behaviour has to be finished
• For example, the shape of an egg-shaped object triggers the goose mother to brood on it even if it clearly isn’t an egg triggered by the shape of the object, will complete all appropriate behaviours
What is the agression fixed action pattern of stickleback fish in spring?
o If a red-underbelly male approaches, the stickleback male will attack
o The attack begins with a threat display, an action pattern consisting of head-down posture and spread fins
o Releasing stimulus/Sign stimuli- the intruder’s red underbelly
Even very crude models, if introduced near the male, will be threatened if their undersides are red
What is the sex fixed action pattern of male stickleback fish in spring?
o If a female fish comes along, then the fish is courted
o Action pattern- a zigzag dance
o Releasing stimulus/Sign stimuli- the swollen underbelly of the female fish heavy with eggs
Crude models with swollen undersides will be courted while good models without swollen undersides won’t be
1. The male has a red-belly
2. The male builds the nest
3. If female has extended belly full of eggs, it bites the female down to the nest
4. The male then leads the female to his nest
5. If she follows, he points to the next entrance with his nose
6. If she swims into the nest, he nuzzles her posterior, causing her to release her clutch of eggs
7. He then swims in after her, depositing sperm to fertilise the eggs
8. The male takes over the job of caring for the developing eggs
9. If the female is not interested once shown the nest, she will swim away `
o Every stage of the sequence is an action pattern (instinctive pattern of response) evoked by releasing stimuli
Are sex/aggression responses in male stickleback fish stimulus bound?
Yes
What are the two phases to sexual/agressive behaviour in ,male stickleback fish?
o During the first, arbitrary learned responses can expand the sexual or aggressive repertoire
o One the mate or rival is at hand, behaviour funnels down into inflexible, stimulus-bound instinctive reactions
Who mainly studied the stickleback fish?
Tinbergen
What is Lorenz and Tinbergen’s ethological model of instincts?
They have a hydraulic view of instincts
- Specific to breeding season
- Initiated by sign (or key or releasing) stimuli
- Filtered by an innate releasing mechanism
- This activates action specific energy or a central pattern generator (modern idea)
- Released by biological state but requires sign stimulus to trigger - Results in a characteristic behaviour called the fixed action pattern
- The FAP can set up the conditions for the next sign stimulus, so the next behaviour in the sequence is triggered
- And so on
What are supernormal stimuli, and what is an example of this in the current media?
- Supernormal stimuli-a stimulus that elicits a response stronger than the stimulus for which it evolved, even if it is artificial
- This is used in cartoons, where animals are made cute based on the proportions of the human baby (large head, no neck…) which we are innate to care for.
What are the three motivational states?
- Arbitrary
- Learned
- Goal directed response
What does innate mean?
o Innate- behaviour, or some influence on behaviour, that is not acquired through specific learning experiences
o Just because something is innate doesn’t mean it’s fixed e.g. aggression in male stickleback fish due to red underbelly releasing stimulus doesn’t mean other conflicting factors can’t enhance/ inhibit aggression
o This behaviour can be m
odified by learning
How can we tell if behavior is instinctive?
- Biological basis
- Cross-species similarity
- Cross-cultural similarity
- Separated identical twin-studies
- Developmental studies
What did Ekman and Friesen do?
o Photographed 6 people with different emotions and took them to different cultures around the world to see if people recognised these emotions, and henceforth if the recognition of emotions was instinctive
What did Eibl-Eibesfeldt find in human expressions?
o Had a side-viewing camera to capture human facial expressions
o Eyebrow flash recognition between people use eyebrows for communication
o Facial expressions:
Innate around the world
Blind people smile like everyone else even though they’ve never seen a smile before instinctive
o Acting coy:
Extremely feminine behaviour
Involves:
• A direct look
• A smile
• Face being hidden
• Another direct look
o Women become more flirtatious near ovulation
What is Pinker’s view on instincts?
• The language instinct, 1996:
o Linguistics as a way to study innate abilities of people
o Language is a spontaneously created behaviour in all people, but it’s very variable
Universal basis Born with mechanisms to learn languages
Languages are spontaneously generated around the world
In different villages, home-made sign language is different
o An instinct is an urge and competence
o It is an ability to behave in a certain way coupled with a tendency to behave that way at appropriate times
How do instincts affect human behaviour?
• The behaviour is purely instinctive • The behaviour is a modified instinct o New eliciting stimulus o Modified response to the same stimulus • A predisposition to behave • A predisposition to acquire certain behaviours • Phase sensitive learning • Little or no role in the behaviour at all