10. Brain and behaviour Flashcards
What is the Theory of memory I: Stages?
Memory is a construct, for which there are many stages:
• Registration - input from our sense into the memory system
• Encoding - processing and combining of received information
• Storage - holding of that input in the memory system
• Retrieval
What is the Theory of memory II: Duration?
There are conceptual divisions in memory systems based upon how long a memory lasts:
• Sensory - seconds
• Working/short-term - few minutes
• Long-term - indefinite period of time with infinite capacity
Can information be transferred directly to long-term memory?
Yes, depending on what it is e.g. sensory aspects of traumatic memories
Which part of the brain is highly activated in traumatic moments?
Limbic system - very important in memory too
How can we overcome the disadvantageous effect of sensory information of traumatic events in our long-term memory?
• Overcome the nature of the memory
- make it less sensory and more verbally accessible
• This avoids simple sensory stimuli triggering sad and upsetting memories
Which parts of our sensory experiences are more likely to pass into working (short-term) memory?
Parts that we attend to
How can we increase the chance of transferring sensory experiences into working memory?
Rehearsing (this can then be stored and put into long-term memory)
What is retrieval, is it active or passive, and what type of memory allows this?
- Recovering stored information from the (long-term) memory system
- Active process
- Working memory allows this retrieval process
What are the 2 types of long-term memory (Theory of memory III)? Describe them and their further subtypes
Declarative - available to conscious retrieval and can be declared (propositional)
• Episodic - what did I eat for breakfast?
• Semantic - what is the capital of Spain? (knowledge)
• Working - what did I just say? (short-term)
Non-declarative - causes experience-induced change in behaviour, and can’t be declared (procedural)
• Priming - subliminal advertising
• Skills - how to ride a bike
• Conditioning - phobias
What questions can you ask a patient to asses their memory?
Do you have difficulties with: • remembering conversations? • losing track of conversations? • repeating questions/information? • finding your way in familiar areas?
What questions can you ask to check recent episodic memory?
- What did you have for dinner last night?
- What are some of the headlines in the news?
- How is your team doing at the moment?
- How did you get here?
What happened when Henry Molaison underwent surgery for uncontrollable epileptic seizures?
- Had specific lesions in the medio-temporal lobes, so his hippocampi were removed
- Developed significant anterograde (and some retrograde) amnesia after surgery
- Seizure vanished, but so did his ability to develop memories
- Could learn new skills and recall general aspects of life, but couldn’t remember new experiences (like episodic and semantic memory)
- Working and procedural memory was fine
Which parts of the brain does episodic memory involve?
Medial temporal lobes • Hippocampus • Entorhinal cortex • Mammilary bodies • Parahippocampal cortex
Which memory system is important in knowing how to do things?
Procedural
Which part of the brain plays a key role in learning motor tasks?
Cerebellum
Is the left or right hemisphere more concerned with verbal information processing?
Left
Which part of the brain do theories suggest is important for processing new information and activating memory (remembering)?
Hippocampus (different evidence shows it may be one or the other, or both)
What is the serial position effect, with reference to repeating a list of words back to a person?
This is where we tend to remember the words towards the beginning and end of the list
What factors is the probability of recalling a word related to?
- Order in the list
- Personal salience of words
- Number of words
- Chunking or other encoding strategy
- Delay time
- Distraction
In consultations, we give large amounts of information to patients, so how can we get them to remember the key things?
- Give important information at the beginning and end of a consultation
- Emphasise and repeat important information a few times
- Make the information salient to the person (link to their problem specifically)
- Chunk information into meaningful categories
- Avoid overloading
What did Barlett’s ‘War of the Ghosts’ study show?
Study where student read a story and reproduced it to another person, with changed order, rationalisations and omissions
- Majority of people think that memory accurately records events as we see and hear them
- Most people don’t realise that it is susceptible to distortions
Can changing words when describing an event change someones perception of people’s memory?
Yes
• e.g. video showed to people of a car collision
• people asked how quickly the cars “hit” or “smashed” into each other
• When using the word “smashed”, they estimated a higher speed
What are 3 strategies that work in committing information to memory i.e. how to study?
1) Rote
• Frequent repetition
• Form a separate schema
• Least efficient
2) Assimilation into existing networks
• Learning by comprehension of meaning
• Fitting new information into existing schemas
• Can only be used where there is a link between old and new knowledge
3) Mnemonic device
• Artificial structure for reorganising or encoding information to make it easier to remember
• Useful when info doesn’t fit into existing schemas
• e.g. visual imagery, hierarchies, acronyms
Give 4 examples of unknown causes of memory problems?
- Vascular
- Infectious
- Toxic-metabolic
- Autoimmune
Can lesions in the pre-frontal cortex affect memory?
Yes
What are the early features of Alzheimer’s disease?
- Disorientation for time
- Difficulty in finding way around familiar places
- Anterograde and retrograde component
What type of abilities are usually preserved till late in memory disorders?
- Ability to perform over-learned skills e.g. driving, swimming, cooking etc.
- Implicit memory - ability to learn a motor skill or react faster the second time
How long does transient global amnesia last?
4-5 hours with complete recovery
What is retrograde amnesia?
- Loss of personal identity
- Intact new learning is unusual
- May be a psychiatric cause
- Psychiatric history more likely to be present
- Normal performance on memory test, but can suffer remote memory loss
- Recovery may be sudden and triggered by emotional event
What did the brain training study show?
- Six-week online study, where participants were trained on cognitive tasks
- Aim to improve reasoning, memory, planning, etc.
- Improvements observed in every one of the cognitive tasks trained
- No evidence for transfer effects to untrained tasks - even when cognitively closely related
Brain training makes you good at doing brain training tasks, but doesn’t generalise into other day-to-day cognitive abilities
What is a phoneme?
The smallest unit of speech sound in a language that can signal a difference in meaning e.g. ø
How many phonemes can humans produce, and how many are there in the English language?
- Humans - 100 phonemes
* English - 44 phonemes
What are morphemes?
- The smallest units of meaning in a language
- Typically consist of one syllable e.g. the
- Morphemes are combined into words
What is syntax?
- Rules and principles, which govern the way in which morphemes and words can be combined to communicate meaning in a particular language
- i.e. the arrangement of words to create well-formed sentences
What is the Theory of Universal Grammar?
- Under normal conditions, human beings will develop language with particular properties
- A certain set of structural rules are innate to humans, independent of sensory experience
At what age do babies tend to say their first recognisable words (as one-word utterances)?
12 months
At what age do babies say their first rudimentary sentences, usually consisting of two words e.g. more milk?
12-18 months
At what age will a child have learned the basic grammatical rules (combining nouns, adjectives etc. into meaningful sentences)?
4-5 years
What is the critical period of language acquisition?
- The first few years of life constitute the time during which language develops readily
- After this period, language acquisition is much more difficult
Is there a genetic contribution to language development?
- Large genetic component to language development
* e.g. language problems associated with mutations of FOXP2 gene
Which hemisphere is most language control lateralised to?
Left hemisphere
What percentage of right-handed people have left-hemisphere dominance, and left-handed people have right-hemisphere dominance for language?
- 95% of right-handed people have left-hemisphere dominance
- 18.8% of left-handed people have right-hemisphere dominance
(shows dominance of left hemisphere)
What is Broca’s aphasia and the symptoms of it?
Expressive issue
• Can understand speech but struggle to generate a response
• Non-fluent speech
• Impaired repetition
• High risk of depression - can’t get across what they want to say
What is Wernicke’s aphasia and the symptoms of it?
Receptive issue
• Problem in comprehending speech
• Fluent meaningless speech - no problem with speaking
• Paraphasias - errors in producing specific words
• Neologisms - nonsense words
• Impairment in writing and reading - varies depending on site and extent of lesion
What types of paraphasias can a Wernicke’s aphasia patient get?
- Semantic paraphasias - substituting words similar in meaning e.g. barn instead of house
- Phonemic paraphasias - substituting words similar in sound e.g. house instead of mouse
What connects the language and speech areas of the brain?
Arcuate fasciculus
Describe the passage of the signal from speech in the brain to be able to understand and reply to it?
- Hear information
- Auditory cortex processes it
- Wernicke’s area tells you what that information means
- Transmitted to Broca’s area via the arcuate fasciculus
- From the Broca’s area, the person can decided how to respond
- Broca’s area => motor cortex (controlling breathing and pharynx)
- Speech is produced
Is there just one connective tract relevant to language?
- Modern findings show that there are many
- e.g. uncinate fasciculus
- Language function is widely distributed, far beyond Broca’s and Wernicke’s area
What conditions are associated with aphasia?
Lesions to the dominant hemisphere can be caused by: • stroke • trauma • cerebral tumour • neurodegenerative conditions
Transient aphasia can be associated with:
• transient ischaemic attack (TIA)
• migraine
What is dysexecutive syndrome?
- Disruption of executive function
- Encompasses cognitive, emotional and behavioural symptoms
- Closely related to frontal lobe damage
- Can result from many causes e.g. trauma, tumours, degenerative diseases and psychiatric conditions
What are execute functioning skills?
Mental processes that enable us to plan, focus attention, remember instructions and juggle multiple tasks successfully
Describe the 2 types of presentation of dysexecutive syndrome?
1. • Hypoactivity • Apathetic (lack of interest) • Emotional bluntness • Reduced empathy
2. • Hyperactivity • Impulsive • Disinhibited • Emotional dysregulation • Socially inappropriate
Opposite presentations, but can co-occur at different times
What cognitive difficulties do people with dysexecutive function have?
- Attentional and working memory difficulties
- Poor planning and organisation
- Coping with novel situations
- Switching from task to task
- Keeping track of multiple tasks
- Complex/abstract thinking
What effects do deficits associated with the following regions of the frontal lobes have:
• Orbito-frontal
• Medial
• Lateral
- Orbito-frontal - impulsivity
- Medial - loss of spontaneity
- Lateral - inability to formulate and carry out plans
What is cerebellar cognitive affective syndrome?
People with lesions in the cerebellum may also have emotional, cognitive and behavioural changes, reflective of a frontal lesion
Why might someone with a thalamic infarction appear to have a frontal lobe lesion?
The subcortical regions (includes the thalamus) sit posteriorly to the frontal lobe and are highly interconnected with it
