Memory and Language Flashcards
What is the multi-store model?
Atkinson and Shiffrin
A model of memory consisting of modality-specific sensory stores, a short-term store of very limited capacity, and a long-term store of essentially unlimited capacity capable of holding information over time.
What is the sensory store of the multi-store model?
Consists of an
iconic store - visual.
Echoic store - auditory
What was Sperling’s experiment?
Investigating iconic store. Briefly present letters in a grid array. Participants could only report 4 or 5 letters correctly, but in a ‘partial’ report condition, could report most of the letters from the requested line if the delay between removal of the array and presentation of the prompt was less than 1s
What was Treisman’s study on the echoic store?
Dichotic listening. Auditory message to one ear, asked to repeat back while ignoring a second message from the other ear. If the second message was identical to the first, but started at a different time, participants only noticed if they started within 2s of each other. Suggests unattended information persists for approx. 2s.
What was Miller’s experiment?
- Miller: short term memory span Asked subjects to recall digit strings. Typically, could recall 7+-2 digits, same for letters and even words. Words being treated the same as letters suggests that short term memory holds 7+-2 chunks. Can retain information by rehearsing it.
What was Peterson and Peterson’s experiment?
- Peterson and Peterson: asked participants to remember a stimulus for a few seconds while counting backwards in 3s to prevent rehearsal. Ability to remember a stimulus diminished rapidly, suggesting information decays from the short term store within seconds.
What was Waugh and Norman’s experiment?
manipulated speed with which digits were presented to participants, and found that digit recall was more or less unaffected, suggesting that short-term memory forgetting is due to interference from exposure to additional information, rather than the passage of time
Decay hypothesis: fast>slow
Interference hypothesis: fast = slow
What was Rundus’ experiment?
Rundus: made people rehearse out loud. The more frequently a word rehearsed, the better it was remembered.
What were the criticism’s of the multi-store model?
- Model says processing in the short-term store is required for encoding into long-term memory - Patient KF
- Assumes short and long term stores are unitary, operating in a single way - patient KF
Who was patient KF?
Parieto-occipital lobe damage. Defective short term memory (digit span) but preserved long-term learning and recall. Had worse short-term memory for auditory letters and digits than for visual stimuli - suggests that there may be distinct short-term memory stores for different types of material.
What was the model created aiming to improve the multistore model?
Baddeley & Hitch Working memory model
What are the components of the Working Memory model?
3 primary components:
- Auditory-verbal phonological loop (speech-based)
- Visuo-spatial sketchpad
- Modality free central executive
What is the role of the central executive?
Selecting and initiating cognitive processing routines e.g. manipulation beyond simple repetition
What is the evidence regarding a speech based temporary store existing?
- Treisman
- Miller
- Peterson and Peterson
- Rundus
- Baddeley’s word length and phonological similarity effects
What is the phonological similarity effect?
Baddeley
Serial recall of a list of phonologically similar words is significantly worse than from a list of phonologically dissimilar words.
Suggests speech based representations are used in storing the words and that recall requires discrimination between memory traces, which is more difficult for phonologically similar words.
What is the word-length effect?
Baddeley
Recall of a list of long words is worse than a list of short words
Confirmed depended on phonological loop by asking participants to silently mouth digits (articulatory suppression) during presentation and recall of words. Eliminated the word-length effect, suggesting that phonological storage capacity is determined by rate of rehearsal.
How did Baddeley structure the phonological loop?
Phonological store perceives speech
Articulatory control process linked to speech production that gives access to the phonological store
How does Baddeley’s structure of the phonological loop explain the phonological similarity effect and the word-length effect?
Confusions between similar representations in the phonological store
Takes longer to rehearse longer words via the articulatory control process
What did Baddeley do to elucidate a difference between auditory-verbal and visuospatial short term memory?
asked participants to encode material using either rote verbal learning or an imagery strategy. When task was combined with pursuit rotor tracking, performance using the imagery based strategy was disrupted, but not the verbal.
How did Baddeley and Lieberman divide the visuospatial sketchpad?
- Baddeley and Lieberman: asked participants to encode material using either rote verbal learning or an imagery strategy again. Split concurrent task into visual (making brightness judgments) and spatial (pointing at a moving pendulum while blindfolded, guided by an auditory tone). Learning of the imagery-based strategy was most clearly disrupted by the spatial concurrent task, whist the visual task did not interrupt significantly
What did Logie argue?
That the visuospatial sketchpad should be divided into two components: visual cache (passively stores information about visual form and colour, subject to decay and interference by new visual information), and an inner scribe (processes spatial info and allows active rehearsal of information in the visual cache).
Who is patient NL?
Preserved perceptual skills, but could not describe details of a scene from memory (fine visual cache, but no inner scribe?)
Who is patient LH?
Performed better on spatial processing tasks than visual imagery tasks
How do we measure memory?
1. Conscious behavioural methods: Objective: accuracy/reaction time Subjective: remember/know, confidence, qualitative measures 2. Unconscious behavioural methods: priming, conditioning, habits - Psychophysiological GSR/HR - Electrophysiological EEG ECG EMG MEG - Haemodynamics PET SPECT fMRI
If you are given a list of words to remember and then immediately asked to recall them, you will experience a serial position curve. What does this show?
Primacy effect = remember the first few items better
Recency effect = remember last few items better
What did Glanzer and Cunitz do?
Showed that the recency effect can be eliminated if participants counted backwards prior to recall, supporting the link to short-term memory of the recency effect. Showed that counting backwards had no effect on primacy effect, while manipulating word familiarity/presentation rate/age of participant does affect the primacy effect (but not the recency effect) so attributed this to long term memory
What separates short term and long term memory experimentally?
Primacy and recency effects
Patient HM
Who was patient HM?
Patient who had medial temporal damage and had impaired long-term memory , but normal digit span
Intact recency, impaired primacy
- Impaired explicit memory, not implicit
- Impaired episodic memory, but not semantic
What does fMRI tell us about where in the brain long and short term memories are associated with?
- fMRI studies: Schacter and Wagner – activity in medial temporal lobe when participants were encoding and/or retrieving information from long-term memory. Henson – asking patients to retain information in short-term storage associated with inferior frontal and parietal cortex.
What did Ebbinghaus do?
Taught himself lists of nonsense syllables then repeated them until he could recite them correctly twice. Measured time to learn the lists, then time saved in relearning them after various delays. Retention decreased with a longer retention interval, and rate of forgetting slowed down after the first hour or so.
What is the capacity of long term memory?
Theoretically unlimited, realistically limited by number of neurons and synapses in the brain (10^15).
What did Standing do?
Tried to locate the limit of capacity of long term memory by testing memory for thousands of pictures, but found good memory for 10,000+
What did Lindauer suggest?
That capacity of long term memory may be constrained by the rate of acquisition.
How do people forget?
Very rapid over first hour, then logarithmically
Primarily due to interference from other experienced events:
1. Proactive interference where previous learning interferes with later learning
2. Retroactive interferemce where later learning interferes with previous learning
What did Underwood find?
The more nonsense syllable lists a participant had previously learnt, the more forgetting of new syllables the participant exhibited after 24h - proactive interference
What is an example of retroactive interference?
Eyewitness memory for an event can be interfered with by post-event questioning
Who split long term memory?
Squire
What are the divisions of long term memory?
Implicit - Perceptual representation system: Priming - Procedural memory: Motor skills Explicit - Episodic - Semantic
What are the different memory tasks to test explicit and implicit memory?
- Schacter: Memory tasks. Ask a participant to study a list of words. Explicit memory task = recognition old or new, cued recall, free recall. Implicit tasks = fragment completion, wordstem completion, degraded word naming.
What did Jacoby and Dallas find regarding retaining information in long term memory?
Effect of different levels of processing at encoding. Words encoded using tasks e.g. does it contain an R, does it rhyme with drain, etc. Found that deeper levels of processing improved explicit memory but had little effect on implicit memory.
What do medial temporal lobe amnesiacs show about long term memory?
E.g. patient HM
Impaired long term memory
On pursuit rotor or Gollin figures tasks, performance of amnesics improves over trials, despite the patients being unable to recall having done the test before
Define double dissociation
When you can show two mental tasks to be distinct by two lesions leading to contrasting symptoms
What does medial temporal lobe damage cause?
Impaired explicit long-term memory
Which brain region, when damaged, affects implicit memory?
Occipital
E.g. patient HM
Impaired long term memory
On pursuit rotor or Gollin figures tasks, performance of amnesics improves over trials, despite the patients being unable to recall having done the test before
Give two patients that exemplify the double dissociation between explicit and implicit memory
HM lost explicit not implicit
MS lost implicit but not explicit
Define episodic memory
Memory of specific events or episodes occurring in a particular time and place
Define semantic memory
General knowledge about objects, people, facts, concepts, meanings, without awareness of where or when the information was learned
Stored in the lateral temporal cortex
What did Jacoby and Dallas fine regarding episodic and semantic memory?
Double dissociation: reading a word out of context improved semantic memory, whereas generating word themselves improved subsequent episodic memory.
What did Vargha-Khadem et al show?
Children with selective hippocampal damage showed impaired episodic, but performed well on tests regarding semantic.
Explain the double dissociation shown by dementia
Alzheimer’s –> medial temporal lobe atrophy
Early semantic Dementia –> lateral temporal lobe atrophy. Simons et al, asked patients to perform a semantic task and later tested episodic memory for same drawings. Alzheimer’s = impaired semantic and preserved episodic. Semantic dementia = preserved episodic, impaired semantic.
What is the problem with studying patients with Semantic dementia?
Lateral temporal lobe damage so often also have language issues and can’t do word related tasks
What are the two major forms of amnesia?
Retrograde (forgetting of events occurring prior to trauma)
Anterograde (inability to retain new information in a permanent form)
What are the causes of amnesia?
Anoxia, ischaemia, encephalitis, alcoholism and associated dietary insufficiency (thiamine deficiency in Korsakoff’s syndrome) and neurosurgery. Alzheimer’s.
Where does the pathology of Alzheimer’s strike?
Hippocampus and entorhinal cortex within the parahippocampal gyrus of the medial temporal lobe
What is the difference between forgetting and amnesia?
Forgetting prevents the brain being burdened with useless information. Amnesia is a pathological memory loss.
What was resected in patient HM?
Bilateral medial temporal lobe: hippocampus, amygdala, overlying temporal cortex
How was HM studied?
- Impaired long term
- Showed intact digit and spatial span - Impaired explicit
- Deficit in matching to sample after delay, but not immediately, showing that he understood the task - Impaired episodic
- Severe anterograde
- Mild retrograde
What does a right sided medial temporal lobe resection result in?
Non verbal memory deficit
What does a left sided unilateral medial temporal lobe resection result in?
Verbal memory deficit
What does the Corsi block tapping test test?
Spatial span
Subject must copy a sequence tapped out by the examiner on the blocks. Numbers visible tot he examiner but not the subject.
Who is patient NA?
Patient with diencephalic amnesia
Lesion of mediodorsal nucleus of the thalamus
Severe anterograde amnesia
What can Korsakoff syndrome cause?
Thiamine deficiency
Damage to medial thalamus, fornix and mammillary bodies
Diencephalic amnesia
Which characteristic lesion causes selective loss of short term memory? What else happens?
Temporo-parietal junction
Often conduction aphasiac.
Where might short term memory in vision be stored?
Unimodal association areas related to the particular modality in question e.g. post parietal in case of spatial span
What are agnosias?
Higher level sensory deficits
Inability to recognise things
Define prospagnosia
Patient can’t see faces
What are the two main types of visual agnosia?
Associative: patient cannot recognise objects, name them, or use them appropriately, but can draw them accurately
Apperceptive: patient can name if the appropriate perceptual cues are present, but cannot draw the object, or name it if it is presented in an unusual view
What is an example of a condition where procedural memory is impaired?
Huntington’s
Perform better on word recognition
What are the types of amnesias?
- Medial temporal lobe
- Diencephalic
- Selective short term loss
- Loss of special knowledge systems (agnosias/apraxias/aphasias)
- Procedural
Which brain structures underly declarative and procedural memory?
Declarative = temporal lobe, diencephalon Procedural = basal ganglia and cerebellum
What is DNMS and what does it show?
Delayed non matching to sample
Impaired recognition memory
Monkeys have to remember having seen a junk object over longer and longer delays. At the choice stage, monkey has to choose between the junk object or a novel object. Has to choose novel object, indicating that he remembered which of the objects was familiar. Large impairments following combined damage to hippocampus, amygdala, entorhinal and perirhinal cortex
How do you show that moneys with MTL damage have intact skill learning?
Lifesaver motor-skill task
Measured by improved ability of monkeys to retrieve a sweet from a bent stick
How do you show monkeys with MTL damage have mild retrograde amnesia?
Mild retrograde amnesia – monkeys trained on concurrent object discriminations pre surgery at 2/4/6/8/10/12 w. Impairment only on object discriminations post-surgery that were learnt 2-8 weeks before surgery.
