8-Memory Flashcards
What is Memory?
Preservation/record of experience, including sensations, emotions, thoughts & beliefs; actionable preservation (not just storing, but retrieving it so we can act on it)
Two different kinds of information serve different memory functions. Knowledge requires what?;
Experiences require what?
Semantic memory;
Episodic memory
Describe the characteristics of Semantic memory
Not contextual; abstract; non-autobiographical; knowledge based (e.g. “what is a hippopotamus?”); read or identify (a word for instance)
Describe the characteristics of Episodic memory
Context sensitive; personal; autobiographical; event based (e.g. “did you see a hippopotamus at zoo last week?”; recall (e.g. “did this word appear in the list of words earlier?”)
Most of our cognitive activities, decisions and action plans use what kind of information?
Both episodic and semantic information
Compared to a computer, which does things rapidly, accurately & one at a time, the human brain is a slow, powerful, parallel processor. What is needed in a workable human memory system?
Access past experiences and knowledge to deal with a current situation; a filing system that allows us to access the relevant information; forget similar memories that no longer apply; do this job efficiently during ongoing actions
In computers, memory is organized by topic, date, time & place. In humans, memory is organised by what?;
In computers, memory is accessed from pre-defined cues. In humans?
By experiences & significance of information;
Memory access-cue is less well specified
Computers have the capacity for a rapid serial search of memory. What do humans have?;
In a computer, information is completely & accurately represented in memory. In humans?
Slower memory access, in parallel with other operations;
Only part of an experience is stored according to personal relevance
Information in a computer is not altered during storage or retrieval. In humans?;
In a computer, memories remain separate within the memory system. What occurs with humans?
Information is re-interpreted or distorted over time & during retrieval;
Generalisation, composite memories & interference
Details of context of occurrence and source of memories are retained in a computer. How does this compare to humans?
Source information may be lost (can’t aways recall where information came from)
On repeated eye-witness questioning, witnesses may remember something that was in fact suggested during prior questioning, without realising the source of this info. What is this known as?
Misinformation effect
WM reflects ideas about the cognitive workspace. It’s the memory used for current actions & has a duration of several seconds or minutes. How does long-term (secondary) memory differ from this?
Information is more permanently stored & must be retrieved for use
What evidence was found by Murdoch (1962) to support the distinction between WM & LTM?;
How was the study carried out?;
Memory accuracy depended on position in which a word occurred in the study list. What was found?
The serial position curve (first finding dates back to Ebbinghaus with his forgetting curve);
Participants had to remember a list of 10-30 words, presented singly for 1 or 2 secs; then they freely recalled the words in any order;
Best recalled were items at beginning & end; worst were items in middle (Primacy & Recency)
What does the Primacy effect reflect?;
What is the Recency effect found for?
Transfer of items to LTM (fresh mind, nothing to interfere, more rehearsal at the beginning);
Later list-items that are still “fresh” in WM (test usually done immediately after)
When participants in Murdoch’s study were asked to count backwards by 3s from 100 at the end of the study list, what occurred?;
What has subsequent evidence indicated about the recency effect?
The recency effect was eliminated, but not the primacy effect (supporting interpretation of serial position effect);
It may have other causes related to LTM
WM has low capacity & evidence has shown forgetting due to decay and interference from later and prior items. Although Miller (1956) proposed “the magical number 7” for WM capacity, what does recent evidence suggest?
That original estimates were optimistic & inflated by contributions from long-term memory (i.e. rehearsal); Cowen suggests 4 is a better estimate; WM is also highly sensitive to order of item presentation
Describe Atkinson & Shiffrin’s (1968) Modal Model of memory
Info from environment enters sensory memory (iconic & echoic); most quickly fades, if attention’s given to process & identify, it’s transferred to STM; some is forgotten; if rehearsed it’s stored in LTM; in retrieval, there’s an interplay between accessing from LTM & STM
According to the Modal Model, what keeps material in STM?;
When material is stored long enough in STM, what happens?
Rehearsal
It gradually gets transferred to LTM (so effectively, rehearsal helps get info into LTM)
According to the Modal Model, what do Sensory stores handle?;
What is its capacity?;
What phenomenon is it relevant to?
Initial sensory analysis (modality specific - one for vision, touch, sound);
High capacity, but material decays quickly unless moved to short-term store;
Attentional Blink
What does Short-term memory store?;
What about the Long-term store?
Holds in memory what’s needed for current actions; control processes involved in rehearsal, coding (chunking), decision & retrieval strategies;
Has a vast capacity & long-term retention; supports short-term store (identifying words, objects)
What are some problems with the Modal Model?;
Despite this, what did these ideas of distinctions & separate memory stores influence?
Rehearsal isn’t what gets material into LTM; there’s a more complex interplay between STM and LTM, not a simple sequential transfer of information;
The development of Baddeley & Hitch’s (1974) STM model
In typical episodic memory paradigms, where participants employ intentional (explicit) retrieval to recall words on a list, what are the gold standard tasks used;
How would a typical experiment be conducted?
Recall & recognition; Study phase (see words one at a time, do a task on each (e.g rate pleasantness); retention interval (mins, hrs or days); recall test (say or write words from study list) or recognition test (are words from study list, yes or no?)
What sort of materials are usually used in typical episodic memory tests?;
What’s the dependent variable in these tests?
Nonsense words, faces, pictures, abstract shapes, with & without verbal labels;
Accuracy - % of number correctly recalled
What’s a Free recall test?;
What’s Serial recall?;
Long-term serial recall?;
Cued recall?
Participants produce the words in any order that they wish, until they can’t recall any more;
They produce the words in the order in which they were studied;
Feasible only with short lists (like passwords);
A cue is provided for each word on the study list (makes recall easier)
How is a Single item recognition test conducted?;
What’s recorded?;
What do participants decide in a Choice test?;
What about an Associative recognition test?
Each memory item (picture, word, feature from face, etc) is presented one at a time for decision between old vs. new (unstudied) items;
Accuracy (sometimes latency also);
Which word is old? (e.g. house/cottage);
Were the items studied as a pair or not?
Is recall or recognition a more sensitive & flexible test?;
Why is this?
Recognition;
Can test all kinds of items that can’t easily be produced (complex shapes, pictures, symbols); more likely to detect memories that are weaker or incomplete
Why is recording accuracy scores on recognition tests more complicated?;
So what do we need to take into account?
If the participant has 90% correct on old items, we can’t say whether memory is good or whether they just say “old” most of the time (response bias);
False alarms - old responses to new items
If, for example, “plateau” is on the list & “train” is not, what if a participant chooses plateau as old?;
If they choose plateau as new?;
What if they choose train as old?;
If they choose train as new?
It’s a hit;
It’s a miss;
False alarm;
Correct rejection
Suppose participants study a set of face stimuli, then get a recognition test of old and new faces. If they’re offered 50 cents for every face they correctly recognise at test, what can happen?
Bias. They’ll be affected by motivational factors & information provided favouring old over new
If participants are presented with faces in distinctive contexts (e.g., different coloured backgrounds), then test faces in their old context or in a new context not seen at study, what may happen?
They may be more likely to say old to a face tested in an old context
If the false alarm rate is low, hits are usually what?;
What kind of task is a recognition test?
Interpretable; groups in different experimental conditions can be compared on Hits if their FA rates are low and similar;
Discrimination task
For tests of items studied under 2 different conditions
(e.g. imagery task or pleasantness judgment for study task), what must the items be?;
Why is this?
As similar as possible;
A difference between item sets may make one set easier to remember (whatever the study task) & they’ll confound
For old (studied) vs. new (non-studied) items in recognition tests, a difference between item sets may give participants what?
A clue to what is new and old
In a between groups experiment, use the same item sets; In a within groups experiment, either match item sets or what?
Counterbalance assignment of items to conditions
Explain how traditional episodic memory tests are Explicit (direct);
In cases of reduced memory function (brain injury), how do participants perform on these tests?
Participants intentionally & deliberately try to retrieve just the items that occurred in the study phase/memory episode;
Very poorly
Participants with reduced memory function may perform well on implicit (indirect) tests. How are these conducted?
Participants are asked at test to identify items or “give the first thing that comes to mind”
In an implicit priming test, participants perform a study task on a list of words (e.g. animal, kitchen, drivel). Then what happens?
There’s no mention of a memory test. But an implicit/semantic memory test is performed with no mention of the study episode (e.g. Lexical Decision Task)
What’s involved in a Lexical Decision Task (LDT)?;
What are 3 other ways of testing implicit memory after priming?
A stream of words will appear & subjects make a speeded word vs. nonword decision for each letter string (e.g. flurb, kitchen, sping);
Name a briefly presented word (kitchen); complete the stem ki ….. with the first word that comes to mind; or free association: What is the first word that you think of when I say “cook”?
In implicit tests, an effect of memory for the study phase is priming (these tests are counterbalanced). What has been found for studied words compared to non-studied words?;
Participants who can’t retrieve kitchen on an explicit test may show what?
Performance at test is faster or more accurate; lexical decision, stem completion & free association test to kitchen is faster for those who studied kitchen than for those who didn’t;
Priming for it on an implicit test, showing that the word was encoded during the study phase
When a recently encountered word is more available or better identified in an implicit test, what has occurred?;
But what can participants who are able to deliberately do?
Priming (a representation of a word has been made more accessible in memory);
Retrieve from the study list during implicit tests (cheat)
What can people who are ageing or with brain injury have difficulty with?
The use of contextual information at encoding and/or retrieval (can’t use context to retrieve a particular episode)
What do patients with Korsakoff’s syndrome (amnesia)
have difficulty remembering?
Information acquired after the onset of their illness & acquiring new information
Schacter, Tulving & Wang (1981) had Korsakoff’s patients answer multi-choice trivia questions (used questions were put back in the question pile). Which questions were better answered?;
What does this suggest?
Repeated questions, but patients were unable to say that they’d seen the questions before;
That explicit memory is lost, but there are implicit (semantic) memory effects; patients appear to be unable to use contextual and source information
Episodic memory tasks date from Ebbinghaus (around 1885) where he used himself as his own subject. What did he do?
Studied a series of nonsense syllables until he could recite the series perfectly twice; tested recall of the series at different time delays up to one year; used both free and ordered recall
The result of Ebbinghaus’ research was a curve that steadily dropped off, and could be described with a simple exponential equation based on delay between study and test. What is this known as?
The Forgetting Curve (forgetting is systematic & lawful)
The forgetting curve is one of the first really robust findings of scientific psychology. What does it reveal?
That we lose information over time in a systematic, nonlinear fashion
What is Decay?;
What’s a conceptual problem with the concept of decay as forgetting?
When memories fade, or connections between them fade if they are not used;
Decay = “loss due to passage of time”; forgetting = loss of knowledge over time (saying same things in different words; using time as a stand-in for unknown cause tightly correlated with time)
What’s an empirical problem with the concept of decay?
It’s not feasible to get direct evidence of decay at the neural level
Passage of time may affect mechanisms other than decay, such as what?
Effectiveness of retrieval cues (e.g., context); sometimes forgotten things can be remembered later (retrieval failure, not decay); interfering effects of learning occurring after the memory was laid down
Decay theorists tried to show that memories fade over time even when interfering material and changes in cues were controlled. How did Jenkins & Dallenbach (1924) do this?
Compared Obliviscence (forgetting) during sleep & waking. Participants learnt information & compared recall after sleep for several hours vs. wakefulness
By controlling for cues, what were Jenkins & Dallenbach aiming to show?
What were the results?;
What did they conclude?
The sleep group can only forget due to decay; awake group forgets due to both (potentially) decay + interference;
Much more forgetting in awake than sleep condition;
Interference is the largest source of forgetting
What were some limitations in Jenkins & Dallenbach’s study?;
Though decay may play a role in forgetting, what do researchers agree are more important?
Time scale: what if decay matters more at longer time periods (months not hours)?; role of sleep in consolidating information: could reverses effects of decay (need more precise theories of decay to get clear tests);
Interference and other effects located at retrieval
Describe the two broad classes of interference effects in retrieval
Proactive - old information blocks new information (e.g., recall of short word lists gets worse as the number of prior lists increases); Retroactive: new information blocks old (e.g., recall of words from earlier lists poorer than recall of words from current list)
Baddeley & Hitch (1977) studied 2 teams of rugby players’ recall of game details over time; they looked at memory for details of various games as a function of when they were played & how many games were played before & after them. What was measured?;
What was found?;
What effect does this suggest?
Decay - loss of detail correlated with time elapsed after the game; & Interference - loss of detail correlated with number of games;
r = .04 for game-memory with time r = .55 for game-memory with number of games played since the game;
Retroactive interference - forgetting has more to do with interference than decay
What are some conceptual & practical problems concerning repression/inhibition of traumatic memories (e.g. childhood sexual abuse)?
Events that are very traumatic are often well-remembered due to effects of arousal on memory encoding; it’s difficult to establish facts from many years ago; events early in childhood may not be well understood at the time (memories may be poorly retrieved because they are fragmented & difficult to interpret)
It’s not established whether memory repression does occur. Some techniques designed to “recover” repressed memories can create what?;
What must therapists avoid in their questioning with clients?
False memories;
Suggestions about repressed memories for possible childhood trauma/abuse
How can false memories about events be created?
Due to human difficulty with source memory (where, when, who & how of things remembered)
Explain Misinformation Effects, as reported by Elizabeth Loftus
Studies showed reduced memory accuracy in witnesses when incorrect information given during questioning (e.g. did the blue car turn right? - but it was actually a green car)
In Braun et al.’s (2002) study, participants were asked to rate advertisements on various characteristics, including a false ad with Bugs Bunny at Disneyland. What was found?
On later questioning 16% of participants claimed to have met Bugs Bunny at Disneyland (this is impossible as Bugs Bunny is Warner Bros, not a Disney character)
In Deese, Roeidger, McDermott paradigm (DRM), participants study a list of related words - bed, dream, wake, tired, blanket, yawn. What has been found?
About 50% of the time, participants falsely recall and recognise sleep as being on the list & also claim to have a clear memory of seeing it in the list
False memory & misinformation effects show that memory retrieval is what?;
What do memory researchers now recommend?
A re-constructive process, & reinforce the difficulty of recovering accurate source information;
That independent objective evidence be found before courts rely on reports of recovery of repressed memories
In a Retrieval-induced forgetting paradigm by Anderson & colleagues, participants studied category-target pairs, with 2 targets per category - fruit-banana, fruit-orange. They practised retrieving one of the targets, e.g., fruit-or? In the test phase, what happened?;
What did they conclude from this?;
If not inhibition, what else could the effect be from?
Cued recall was poor for unpractised targets from practised categories, e.g. FRUIT-banana (cued by fruit- or fruit-b) & poorer than for categories not practised at all (novel pairs);
That banana was inhibited during practice of orange (denotes an inhibitory link);
The competition between banana & orange
Whilst Anderson et al. argued that inhibition is of the target & not changes in the strength of the category-example links, what did later studies show?;
What did inhibition during practice remove?
Poorer cued recall for a related target paired with a different (unpractised) category; practising RED-blood inhibited not only tomato (category RED), but also other red things, like strawberry (category FOOD); cost for both strawberry & tomato
Competition between blood and other words that could belong with the category RED
The inhibition idea remains controversial. What do traditional interference theories propose?;
In this light, what finding has studies failed to replicate?
Competition at test - e.g, between the fruit-orange and fruit-banana associations (just playing with competition between cue & item strength) with no effect on individual word memories;
That inhibition is observed for related words paired with different category cues
Raaijmakers et al. 2013 have an alternative account with the RED-blood effect. What is it?;
So at test, with the unpractised category FOOD, there is less overlap in stored features between what?
That in retrieval practice of RED-blood, the red-related features of the FOOD target strawberry are activated and stored;
FOOD and the target strawberry, (it’s encoded in terms of red) & recall is poorer
