Chapter 7: Human Memory Retention and Retrieval Flashcards
explain Penfield study about stimulating areas of the brain and how it relates to the idea that forgotten memories might still be in the brain
-Electrical stimulation of the cortex
-Stimulation of the temporal lobes with neurosurgical procedure
-Led to reports of memories that patients were unable to report in normal recall
-When people’s cortices were stimulated they were able to record memories that they were otherwise unable to recall
-No way to know if they remembered things they had forgotten, or if they are just making up things; did not know enough about peoples histories to know
what is experimental evidence (number word association study) that forgotten memories might still exist
NELSON (1971)
-Taught people number-word associations
-Create stimuli that people are going to know the same amount about, we all know the same about numbers and words
-Banana = 12; chair =3 for example
Tested them on these later
-People remembered some and forgot other ones
-Then, retaught them associations that they forgot
-Some people got taught the same associations as before and other people were taught new associations
-When tested, they recalled 78% of unchanged associations, but 43% of changed associations
Even though people had forgotten the original associations, there must have been something that has left behind since they remembered more of them
explain the study with the hammer that highlights potential memory for forgotten memories
People were asked to imagine how an artist would draw or functional uses for an object
-Ex. Hammer
-People told to either imagine ways to use it or how an artist would depict it
Were scanning brain activity while this was going on
-Brain activity pattern analyzer could distinguish between the tasks
-By looking at brain activity, program could tell if someone was picturing the hammer or a utilitarian use for it because it was different in the brain
-Later, when participants were shown words again, it could still distinguish, even for those they could not remember
-Could determine what people were told even if behaviorally a person could not remember what they were told / what they saw before
what are the two theories of forgetting
decay theory and interference theory
what is decay theory
Memory traces simply decay in strength with time
what is interference theory
Memory traces are replaced with interfering material
what are the two kinds of interference with inferencing theory
Retroactive interference: new piece of learning replaces your old information stored
Proactive interference: something you learned in the past gets in the way of your ability to retrieve something in the future
-Ex. Memory of old password is getting in the way of you learning your new one
what does the retention function of memory say
Memory performance systematically deteriorates with delay.
explain the two components of the retention function of memory
1) NEGATIVE ACCELERATION
-Rate of change gets smaller and smaller as the delay increases.
2) POWER LAW OF FORGETTING
-Memory performance deteriorates as a power function of practice.
study that highlights the retention function
Results from Wickelgren’s Experiment to Discover a Memory Retention Function
-Anytime you learn something and test yourself over a period of days on it, when there are times where you are not studying it or looking it over, initially there is a very steep drop off for how much you remember and overtime it eventually drops off
study of retention function with different languages
-Long-term retention of vocabulary words (up to fifty years)
BAHRICK (1984)
-Looking up retention of vocabulary words for languages that people learned
-Graphed a negative acceleration in a retention function
-Flat between 3 and 25 years
-Rapid between 25 and 49 years (due to cognitive decay)
retention function study with rats
RAYMOND AND REDMAN (2006): The retention function
-Showed decay functions may be found in associated neural processes
-Decreased LTP in rats hippocampus with delay
-If you continually stimulate a neuron (with an electrode or by practicing), the more likely it is to fire in the future, but the rate it increases goes down overtime
-Study in rats, when neurons are not stimulated, instead of becoming more likely to fire again, they become less likely to fire again, but this lesser rate of firing decreases over time
explain the interference study with related vs. unrelated words
How Interference Affects Memory
-Had both groups memorize the same list of words, one group memorized a list of similar words, the other group memorized one with different words
-The word that memorized the related list had a harder time recalling the first list than the group who learned something totally unrelated
what is the fan effect
increase in reaction time is related to an increase in the fan of facts emanating from the network representation of the concept.
study about the fan effect
Anderson (1974)
Study: taught people simple sentences / word associations (ex. The doctor is in the bank, the fireman is in the park)
-The first sentence just involves a doctor, the second two sentences just involve a lawyer, the last two sentences involve a park
-The doctor is in the bank
-The fireman is in the park
-The lawyer is in the church
-The lawyer is in the park
Lawyer and church is a 2-1 association because lawyer is associated with two things and church is associated with one
Later on, they showed people these sentences and other sentences they had not seen, interested in how quickly they identified the sentences, seeing how they quickly they could note the things they had seen before
Results: quicker to respond to sentences that has less associations, fits well with spreading activation theory; what is happening here is that the 1:1 ratio activation is not as spread out as the 2:2 ratio
-Memory structure gets half the activation because it is spread out elsewhere
explain the fMRI study with fan effect
(Sohn & colleagues, 2003)
-Response of the prefrontal cortex during verification of facts
-Contrasted high-fan sentences to low-fan sentences
-There is greater response in the high-fan condition.
-The greater activation means that your brain is having a harder time doing the task
what are redundancy effects and how do they impact interference
Major restriction on the situations in which interference effects are seen
-Redundancy among learning materials eliminates interference effects
-When facts are redundant or related to one another, learning more of them actually facilitates memory and makes it easier to remember things
study about redundancy effects and interference
Bradshaw and Anderson (1982)
Study: taught people facts in different conditions (teaching people a single fact, taught people three irrelevant facts, taught people three facts that had an obvious relationship to each other)
-Instant recall: people were good in all conditions
-Week later recall: people were best able to recall the related facts, followed by the single fact, then following by the irrelevant facts (with a huge drop off)
retrieval and interference? (inferencing)
People may infer forgotten information from remembered information.
explain the study about Helen Keller and interference
SULIN AND DOOLING (1974)
-People will use what they can remember to infer what else they might have studied.
-Helen Keller and Carol Harris
-Even when we do not remember things, we can use the things we do remember to make inferences about the things we do not
study: showed people a paragraph about Carol or Helen, the paragraph talked about how troubled they were as a child and what the parents decided to do
-Later shown information and asked if this was in the paragraph or not
-A lot of people when they were asked if they read about a deaf, blind, and dumb person said it was in the paragraph about Helen Keller even though it did not
-Barely any people said this was in the paragraph about Carol
-People were making inferences
study about plausible retrieval
Plausible Retrieval: Participants use of exact retrieval versus plausible retrieval of textual information (Reder, 1982)
INTERACTION EFFECT (CROSS-OVER)
-As delay intervals increase from immediate to two days, participants’ exact retrieval gets slower, but their plausible retrieval gets faster.
-They no longer rely on facts.
Study: read a paragraph and then showed people three kinds of sentences about the paragraph
-Actual sentences, plausible sentences, or neither
-Participants were asked if these sentences were in the paragraph
-Interested in the reaction time for exact recall or plausible sentences (if they were in the paragraph or if the sentences would make sense in the paragraph)
-People were initially much slower at determining if a sentence was plausible, after 20 minutes exact and plausible recall were the same amount of time, and after two days people were able to do plausible recalls better
Showed that exact memory was starting to decay, memory got consolidated and plausibility is easier
explain the accuracy of eyewitness testimony
eyewitnesses are often inaccurate in the testimony they give. (even though this is something that is incredibly impactful in court)
-Even though jurors accord it high weight
subsequent information and memory? and study about this
Subsequent information can change a person’s memory of an observed event.
Loftus et al. (1978)
-Yield sign
-Smashed vs. hit
Participants were shown video of an accident and told to recall how fast the car was going when the car either smashed or hit the sign
Results: people who were told “smashed” said the car was going a lot faster than people who were told “hit”
-Study: researching eyewitness testimony, found that eyewitness accounts can be influenced by information that they encounter after the event
what is false memory syndrome
Individuals claim to recover memories of traumatic events that they had suppressed for years.
-It is possible to create false memories by use of suggestive interview techniques
-Certain kind of therapy, imagination, dream interpretation, hypnosis, and exposure to false information were used which led to people developing these memories
Loftus study about false memory syndrome and therapy
-Ex. Satanic panic: cults that were occurring that would kill babies in the woods
-Controversy over credibility of recovered memories of childhood abuse
-People would go to therapy to recall memories about abuse, therapist would help them recover these memories or at least thought they were
-A lot of the memories that recovered were bizarre and ritualistic, would have left physical reminders, but there were none
explain the study that was looking at determining if memories someone has are true or false
Study that looks at how you can try to determine if the memories someone has are true or false
Show people a list of words having to do with needles, but the word needle does not appear on the list
-Show people three kinds of words after that either did appear on the list, did not appear on the list but should be on the list, or a word that did not appear on the list and should not be on the list
-In many cases people would falsely remember the words that were supposed to be on the list, but were not (words that went along with the theme)
-Looked at brain activity and found a difference
-Found a brain area, parahippocampal gyrus, found a higher level of activation here for the words that were actually on the list
-In the hippocampus, activity was the same
explain Associative structure and retrieval: the effects of encoding context
Recall is better if the physical context during study is the same as the physical context during the test.
study about a person’s appearance and learning context
SMITH et al. (1978)
-Appearance of the experimenter and environment
-An experimenter taught people words in a room, had the same room and experimenter come back and they remembered the words
-If the experimenter was dressed the same the participants remembered more than if the experimenter was dressed differently
explain context learning and scuba diver study
-On shore versus under the sea
-Crossover interaction effect
-Trained people at a scuba diving school on lists of words, people were either trained in dry land or underwater
-Later on they were tested either on dry land or under water, found an interaction: if you learned in dry land you remembered more in this context, same is true for underwater
explain emotions and memory studies
Bower et al. (1978)
-Better memory when emotional state during study matched that during the test
-Elicited via hypnosis
MOOD CONGRUENCE
-Teasdale and Russell (1983)
-Participants recalled more of the words that matched their mood at test.
-Remembered more negative words when they were in a bad mood when learning, and more positive words when they were happy when learning
-This effect is more robust than context and emotional context
state dependent learning (drugs)
Effects of psychoactive drugs (including alcohol) on memory
-People remembered more when they smoked weed while studying and smoked weed while testing, same with smoking a regular cig
-Ex. Playing beer games better when you are already drunk
overall context research?
The degree to which contextual effects are obtained has proved to be quite variable from experiment to experiment.
explain patient HM
H.M.: One of the most studied amnesic patients
-Temporal lobes were surgically removed to cure epilepsy
-Unable to remember new events, or most things from 11 years before the surgery
-Patients with damage to the hippocampal formation show both retrograde amnesia and anterograde amnesia.
result of H.M.’s brain damage showed in the drawing a star example
His unconscious motor centers remembered what his conscious memory had forgot, he got better at drawing a star within a star even though he could not remember the original trials
-Procedural memory (implicit): retrieved unconsciously
-Declarative memory (explicit): can be retrieved consciously
what is korsakoff syndrome a result of and what can it lead to
Korsakoff syndrome
-Result of chronic alcoholism
-Blow to the head
-Or surgically removing this
Can result in:
-Retrograde amnesia
-Loss of memories for events that occurred before an injury
Anterograde amnesia
-An inability to learn new things
difference between implicit vs. explicit memory
EXPLICIT MEMORY
-Knowledge that we can consciously recall
IMPLICIT MEMORY
-Knowledge that we cannot consciously recall but that nonetheless manifests itself in our improved performance on some task
memory in amnesic patients
Often cannot consciously recall a particular event, but will show implicit memory for the event
explain the study about word recall of individuals who do or do not have amnesia
Participants were given a list of words and then later had to recall them, pick words out of a list that you saw
-People with amnesia were not good at this task
-When people had to do word completions for words they saw before, amnesics and normal people were equally as good (word completions: for the word banana you are given ba); the idea is that you are not just starting from 0, this requires more implicit memory
elaborative processing and implicit vs. explicit
Facilitates explicit memories but not implicit memories
what is priming
An enhancement of the processing of a stimulus as a function of prior exposure (Jacoby, 1983)
-Essentially exposing you to a stimulus, fosters implicit memory
Jacoby’s experiment with priming with words
Had people engage with material under three conditions (no context: show people a word and tell them later on that they would have to remember it; context: saw a word and saw it in the context of its antonym; generate: show you the antonym and you had to generate the opposite and you had to remember the opposite), going from less to more elaborative processing
Then had people either try to recall the words they had seen (tested explicit memory) or flash the word for 40 milliseconds
Results: for explicit memory, the more elaborate processing you did the better you remembered it; for implicit memory, the more elaborate processing the worse you did
-Reasoning for results: in the no context you saw the word, context you saw two words, and in the generate condition you did not see the word; so in the no context condition you had the most priming
explicit vs. implicit memory for non-brain damaged individuals
New explicit memories are built in hippocampal regions and PFC
But old knowledge can be implicitly primed in cortical structures
-Such as visual areas
-Decreased activation here during priming (brain is working less hard)
explain procedural knowledge
-Knowledge of how to perform various tasks that is often implicit
-Supported by the basal ganglia and prefrontal cortex
-Cerebellum may be important, also
explain declarative memory
-Explicit memory system that includes episodic and semantic memory
-Supported by the hippocampus
explain nondeclarative memory
-Implicit memory system that includes procedural skills, priming, conditioning, habituation, and sensitization
-Basal ganglia, cerebellum, other cortical structures
