Psychology 5b - Brain and Behaviour Flashcards
List the stages of memory
- Input from our senses into the memory system (registration)
- Processing and combining of received information (encoding)
- Holding that input in the memory system (storage)
- Recovering stored information from the memory system (retrieval)
Describe different durations of memory
- Sensory
- Working or short term memory (7 plus minus 2)
- Long-term memory
Describe a model of memory
- Information in to sensory
- Sensory to long term memory (eg. trauma - treatment involves shifting this pattern)
- Sensory to working memory (attention)
- Rehearsed information will stay in the working memory, otherwise it is lose
- Storage of some information into long term memory
- Retrieval from long term to working memory
List types of long-term memory
- Long term memory may be declarative or non-declarative
- Declarative (episodic or semantic)
- Non-declarative (procedural, priming, conditioning, non-associative loss)
What is priming?
- Priming is the implicit memory effect in which exposure to a stimulus influences response to a later stimulus.
- Used in associative learning
Where is declarative memory performed?
Medial temporal lobe and diencephalon
Which part of the brain is used in episodic memory?
Medial temporal lobes, hippocampus, entorhinal cortex, mammilary bodies and parahippocampal cortex
Describe the case of HM
- Hippocampus surgically removed to treat epilepsy
- Resulted in anterograde amnesia (with some retrograde)
- Episodic memories were lost, but he had procedural memory
What is the hippocampus important for?
- Sematic - knowledge
- Procedural - how to do things
- Working - short term
What is often intact in memory disorders?
Implicit memory (learning)
Describe the case of Clive Wearing
- Muscian, composer, scholar
- Herpes simplex encephalitis
- Temporal lobe damage
- Severe amnesia (could still play the piano and recognise his wife)
- In a permanent state of having just woken up
Compare effect of left sided to a right sided lesion
- Lesions left verbal informaton processing
- Lesion right non-verbal information processing, including face processing (prosopagnosia)
Describe serial position effect
- Primacy effect (memory of the beginning things of a list - lost in Alzheimers)
- Recency effect (memory of the end things in a list)
What 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 (frontally mediated deficits result in difficulty with this)
- Delay time
- Distraction
List clinical implications of recall
- Give important information at the beginning and end of the consultation
- Emphasise and repeat important information
- Make salient to the person
- Chunk information into meaningful categories
- Avoid overloading with information
What is language?
- System of symbols and sounds governed by rules
- No humans let discovered without language
- May be due to innate (critical periods of language acquisition) or exposure
- Both organic and environmental factors are important
Describe structure of language
- Phoneme: smallest unit of speech sound in a language that can signal a difference in meaning (44 in english)
- Morphenes: smallest units of meaning in a language (typically consist of syllables combined into words)
- Words form phrases, which form sentences which forms conversational discorse
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
- Universal grammar - under normal conditions humans will develop language with particular properties (eg. distinguising nouns from verbs)
- Following exposure to non-grammatic language there is formation of a structured language in children
Describe language development
- 1-3 months (crying and cooing, can distinguish speech from non-speech sounds)
- 4-6 months (babbling sounds begin)
- 7-11 months (babbling sounds narrow to form phonemes, tongue is moved with vocalisations and imitations)
- 12 months (first recognisable words spoken as one word utterances)
- 12-18 months (use of single words to express whole phrases or requests)
- 18-24 months (50-100 words spoken, li usually consists of two words)
- 2-4 years (expansion of several hundred words every 6 months, basic language syntax and longer sentences)
- 4-5 years (basic grammatical rules are known)
What happens if a child is not exposed to language?
- Genie - deprived of social interaction from birth until discovered aged 13
- Completely without language, and after 7 years of rehabilitation she still lacked linguistic competence
When is the critical period in language acquisition?
- Between ages of 5 and puberty language acquisition becomes harder (based on feral children, children with brain injuries, second language acquisition)
- Hardest at age 12
- Exposure to other people is therefore required
Describe brain structures underlying language
- Hemispheric specialisation
- 95% right handed people left hemisphere dominance, 18.8% left handed right hemisphere dominance
- 19.8% left handed have bilateral language distribution
How can memory be enhanced?
- Chunking
- Repetition
- Acronyms
What is expressive aphasia?
- Requires lots of effort to express yourself
- Non-fluent speech
- Impaired repetition
- Poor ability to produce syntactically correct sentences
- Intact comprehension
- Affecting Broca’s region
What is receptive aphasia?
- Affecting Wernicke’s area
- Problems in comprehending speech
- Fluent meaningless speech
- Paraphasias (errors in producing specific words)
- Semantic paraphasias (substituting words similar in meaning) and phonemic paraphasias (substituting words with similar sounds)
- Neologisms (non words such as galump)
- Poor repetition and impairment in writing
Describe the language circuit when speaking a heard word (repetition)
- Informaiton about sound analysed by primary auditory cortex and transmitted to Wernicke’s area
- Wernicke’s area analyses the sound information to determine the word that was said
- Transmitted through arcuate fasciculus to Brocas area
- Broca’s area forms a motor plan to repeat the word and sends that information to the motor cortex
- Motor cortex implements the plan, manipulating the larynx and related structures to say the word
List forms of aphasia
- Global aphasia (difficulty with all aspects)
- Mixed transcortical aphasia (impaired fluency and comprehension with intact repetition)
- Broca’s aphasia (comprehension but no fluency or repeats)
- Transcortical motor aphasia (intact repetition impaired fluency)
- Wernickes aphasia (fluency but no comprehension or repeats)
- Transcortical sensory aphasia (intact repetition, impaired comprehension)
- Conduction aphasia (lesion in the connection - fluent and comprehends with no repeats)
- Anomic aphasia (deficit in naming specifically, with fluency, repetition and comprehension)
List conditions associated with aphasia
- Stroke
- Traumatic brain injury
- Cerebral tumour
- Progressive neurodegenerative conditions
What is dysexecutive syndrome?
- Disruption of executive function, closely related to frontal lobe damage
- Executive functioning skills are mental processes that enable us to plan, focus attention, remember instructions and juggle multiple tasks successfully
- Encompasses cognitive, emotional and behavioural symptoms
- Dysexecutive syndrome can result from head trauma, tumours, degenerative diseases, cerebrovascular disease and several psychiatric conditions
- Eg. Phineas Gage
List behavioral and emotional aspects of dysexecutive syndrome
- Hypoactivity
- Lack of drive
- Apathy
- Poor initiation of tasks
- Emotional bluntness
- Theory of mind difficulties and reduced empathy
Could instead have:
- Hyperactivity
- Impulsive
- Disinhibitive
- Perseverative
- Emotional dysregulation
- Socially inappropriate
- Rude, crass, prone to swearing
Describe cognitive aspects of dysexecutive syndrome
- Attentional and working memory difficulties
- Poor planning and organisation
- Difficulty coping with novel situations
- Difficulty multitasking
- Difficulty moving from task to task
- Difficulty with complex/ abstract thinking
Which areas of the brain are different aspects of dysexecutive syndrome associated with?
Different areas of the frontal lobe
- Orbito-frontal (impulsivity and disinihibition)
- Medial (loss of spontaneity, initiation - akinetic mutism)
- Lateral (inability to formulate and carry out plans)
- Connection to cortical and subcortical (basal ganglia, cerebellum, thalamus) structures can result in similar behaviour changes (eg. Parkinsons)
Describe conductive aphasia
- Lesions of the arcuate fasciculus
- Disrupts the transfer from Wernicke’s area to Broca’s area, so the patient has difficulty repeating
- However, retains comprehension and fluency as the Wernickes and Broca areas are intact