Long-Term Memory Flashcards
What experiments show the primacy effect and what explains it?
The primacy effect may be caused by subjects being able to rehearse words at the beginning of the list more and hence transfer these words to LTM. Less rehearsal is possible for words later in the list.
Rundus presented a list of 20 words at 1 word per second and then asked subjects to write as many words as they could remember. He got a similar serial position curve to Murdoch. In another group, Rundus got participants to repeat the words out loud in the 5 sec intervals. Subjects were not told what words to repeat, just that they should keep repeating words. Rundus counted the number of times each word was said. The curve followed the path of the primacy effect, and number of times each word was said slowly decreased towards the end of the list. Words presented earlier in the list were rehearsed more.
What is the recency effect and how is it explained?
The recency effect is the better recall for words at the end of the list. Most recent words are still in STM and therefore are easy for subjects to recall.
Glanzer and Cunitz had subjects recall words after the counted backwards for 30 seconds after recall. This eliminated rehearsal of the words at the end of the list and allowed for words to be lost from STM. Results followed primacy effect but the recency effect was eliminated as would be expected.
What type of coding are there?
Semantic
Visual
Auditory
How are semantic memories encoded in short-term memory?
Wickens and co - subjects were presented with words related to either fruit or professions. Subjects in each group listened to three words, counted backward for 15sec and then recalled the words. They did this for four trials, with different words for each trial. Subjects were using STM. Wickens created proactive interference. Each trial, there was a reduction in the percentage of words recalled.
In the professions group, subjects have professions in trials 1-3 but fruits are presented as the 4th trial. Subjects performance increases in trial 4 - release from proactive interference.
Explain semantic encoding in LTM.
Sachs - subjects listened to a recording and then measured their recognition memory to determine if they remembered the exact wording of sentences in the passage or just the general meaning of the passage.
Subjects forgot the specific words but remembered the general meaning of the passage.
What is the predominate form of coding in STM and LTM?
STM - auditory (i.e. remembering a phone number)
LTM - semantic (i.e. the plot of a movie)
What cases from neuropsychology results in a double dissociation between LTM and STM?
H.M. underwent a procedure to eliminate epileptic seizures - H.M.’s hippocampus was removed on both sides of his brain. H.M. was unable to create new long-term memories. STM remained intact. Shown by psychologist arriving and H.M. greeted as if never met before. Shows STM and LTM are served by separate functions.
Clive Wearing - contracted viral encephalitis - destroyed part of medial temporal lobe (includes hippocampus, amygdala). Wearing lives in last 1-2 minutes. Wearing cannot form new memories.
K.F. - brain damage to parietal lobe. K.F. had poor STM with a low digit span (2). Recency effect in serial curve position was reduced. K.F. had a functioning LTM - he was able to form and hold new memories of events in his life.
H.M./Wearing and K.F. shows a double dissociation - LTM and STM are served by different functions.
What does brain imaging suggest about the location of STM and LTM?
Ranganath and D’Esposito - the hippocampus is essential to forming new LTM. Subjects underwent fMRI - they were presented with a sample face for 1sec followed by a 7 sec delay. A test face was presented. Subjects were asked to identify if the test face matched the sample face. Subjects were in two conditions - novel face - the sample face was new each time. Familiar face - they saw faces they had previously seen in the experiment. Hippocampus activity increased as subjects were holding the novel face in their STM during the 7 sec delay. Activity only changed slightly for familiar face condition. Ranganath and D’Esposito concluded that hippocampus is involved in maintaining novel information in memory during short delays.
Hippocampus and other medial temporal lobe structures are involved in short-term memory as well as LTM.
What are the two types of LTM?
Explicit - aware of memories
Implicit - people not aware of
What are examples of explicit memories?
Semantic
Episodic
What are examples of implicit memories?
Procedural
Conditioning
Priming
What are episodic memories?
Episodic memories are memories for experiences. They often involve mental time travel - experience of traveling back in time to reconnect with events that happened in the past. Tulving describes it as self-knowing or remembering.
What are semantic memories?
Semantic memory is memory for facts. It involves accessing knowledge about the world (i.e. facts, vocabulary, concepts, numbers). Tulving describes semantic memory as knowing.
What are the differences between episodic and semantic memory?
K.C. - suffered damage to hippocampus. K.C. lost episodic memory but semantic memory remained intact.
Italian woman - suffered encephalitis. Had a result of loss of semantic memory but episodic memory remained.
These cases demonstrate a double dissociation.
Brain imagining - Levine and co - had subjects record their everyday experiences as well as some facts from semantic knowledge. When subjects listened in an fMRI scanner, there were some interactions but lots of differences shown in the scan.
What are the interactions between semantic and episodic memories?
Knowledge affects experience - people’s semantic knowledge is required to understand their experiences (i.e. knowledge of baseball rules is required to understand watching a game of baseball).
Autobiographical memories contain both semantic and episodic memories - i.e. meeting a friend at a coffee shop and sitting at favourite table (meeting friend - episodic; knowledge of favourite table - semantic).
What are autobiographical memories?
Memory for specific experiences from our life that contains both semantic and episodic components.
What happens to episodic and semantic memories as time passes?
Petrican and co - determined how people’s memory for public events changes over time by presenting descriptions of events that had happened over a 50-year period to older adults. They had to respond remember/know/don’t know. Found that complete forgetting increased over time; remember responses decreased much more than the know responses. Shows that episodic memories had become semantic memories. Semanticisation of remote memories - loss of episodic detail for memories of long-ago events.
What are the similarities between remembering past events and imagining future events?
K.C. who lost episodic memory was unable to describe events that might happen to him in the future. D.B. also had difficulty recalling past events and creating future events about his life.
Addis and co - fMRI scanning of subjects remembering events about their life and imagining future events. Found that there are similar mechanisms for both remembering past events and creating future events.
What is procedural memory? How is it explained?
Procedural memory is also called skill memory because it is memory for things that usually involve learned skills (i.e. tying shoes).
Wearing - unable to form LTM but could still play the piano. Amnesiac patients can still master new skills without remembering doing so.
H.M. - amnesia from having hippocampus removed - practiced mirror drawing. H.M. became good at mirror drawing with practice but he thought that it was the first time he was doing so.
K.C. - learnt how to stack books in the library.
Other procedural tasks include conversations (i.e. ability to speak and follow rules of grammar).
What is priming? How is it explained?
Priming is when the presentation of one stimulus (primer) changes the way a person responds to another (test). Repetition priming - test stimulus is the same as or resembles the priming stimulus.
Graf - tested patients with amnesia:
1 - amnesiac patients with Korsakoff’s syndrome (caused by alcohol)
2 - patients without amnesia with history of alcoholism
3 - patients without amnesia and with no history of alcoholism.
Subjects rated words on a scale of 1-5 based on how much they liked each word. They had to complete an explicit memory test (straight recall); or word completion test
Amnesiac patients struggled with recall, however in the completion test (test of implicit memory), amnesiac patients performed just as well as the other control groups.
What is the propaganda effect?
Subjects are more likely to rate statements that they have read before as being true, simply because they have been exposed to them before.
Perfect and Askew - subjects scanned articles in a magazine. Each page was faced with an advert. Subjects gave higher ratings on how appealing, eye-catching, distinctive and memorable they were on adverts that they had been exposed to in the magazine. During testing phase they didn’t recognise many of the adverts.
What is classical conditioning?
Classical conditioning occurs when a neutral stimulus that does not result in a response is paired with a conditioning stimulus that does result in a response. i.e. Pavlov’s dogs; tone followed by puff of air to the eye causing an eyeblink. Person starts to blink with presentation of tone.
What is the serial position curve, recency effect and primacy effect?
Murdoch presented subjects with words at a steady rate. Asked subjects to write down words in any order. Found that memory was better for words at the beginning and ends of the list. Serial primacy curve shows this.
Primacy effect - subjects are more likely to remember words at the beginning of a sequence.
Recency effect - subjects have better memory for words presented at the end of the list.
What is maintenance rehearsal?
Repeating information over and over, without consideration of meaning or making connections to other information.
What is elaborative rehearsal?
Considering meaning and making connections to other information is elaborative rehearsal. It is better than maintenance rehearsal.
What is levels of processing theory? What experiment shows this?
Proposed by Craik and Lockhart. Says that memory depends on the depth of processing that an item receives. It distinguishes between shallow and deep processing. Shall processing involves paying little attention to meaning. Deep processing is paying close attention, focusing on an item’s meaning and relating it to something else.
Craik and Tulving - presented words to subjects and asked them three types of questions (physical features; rhyming; fill-in-the blank - does the word fit). Given a recall memory test. Fill in the blanks > rhyme > features.
