Cognitive Approach - Case Studies Flashcards
Milner (1966)
Background: HM had a temporal lobectomy to end his epileptic seizures which began after an accident. This resulted in him losing his hippocampus.
Aim: To determine the extent of HM’s memory deficiency.
Procedure: HM was initially studied by Brenda Milner, administering a range of tests and measures such as personality and mood tests, depression questionnaires, and interviews with psychiatrists. His scores did not indicate depression, anxiety or psychosis and he communicated a good awareness of his condition (i.e. he did not ‘forget’ that he was suffering from anterograde amnesia). He completed a standard IQ test on which his score was normal, however his scores on the Wechsler Memory Scale test demonstrated his severe memory impairment. Milner noted that HM frequently forgot what had happened that day, thought he was younger than his actual age, forgot the names of people he had just met and commented that every day felt as if he was just waking up from a dream. Milner studied him (and later, Corkin) for over 50 years until his death.
Conclusion/Results: The loss of his hippocampus meant that he could retrieve information from before the surgery, but he could not create new memories. He could, however, hold a conversation, showing that he had working STM memory. It appears that the hippocampus is responsible for transferring information from STM to LTM. This supports that there is more than one store for memory.
Glanzer and Cunitz (1966) - study 1
Aim: To see if the interval of time between words on a list would increase the number of words recalled at the start of the list (Their hypothesis was that a longer interval would provide more time for rehearsal, thus making the primacy effect greater). They also wanted to see if each word was read twice in succession, would this improve the overall recall of the list.
Procedure: The sample was made up of 240 Army enlisted men and used an independent samples design. There were 40 men allocated to each of the following condiitons:
- Each word read once at a 3-second rate
- Each word read twice in succession at a 3-second rate
- Each word read once at a 6-second rate
- Each word read twice in succession at a 6-second rate
- Each word read once at a 9-second rate
- Each word read twice in succession at a 9 second rate
Participants were first gives two 5-word practice lists to learn the procedure. Then, they listened to recordings of eight 20-word lists. The lists were the same each group except for the variation of time and repetition. All words on the list were common one-syllable words. After listening to each recording, participants had 2 minutes to write down the words they recalled in any order. A bell was used to signal the end of each list.
Results: It was found that increased time interval between words led to an increase in the recall of all words in the list except for those at the end. The effect of repetition on recall was limited to the 3-second rate. There was no significant effect on recall in the 6 or 9-second rates.
Conclusion: The study supports the theory that the primacy effect is the result of rehearsal. The increased time interval allowed for more rehearsal, leading to a greater overall recall of the list of words. However, as words int eh STM were still available in working memory, there was no significant change in the frequency of recall.
Glanzer and Cunitz (1966) - Study 2
Aim: Focused on the recency effect rather than on the primacy effect.
Procedure: The participants were 46 army enlisted men, and the study used a repeated measures design. participants were first given three 5-word practice lists to learn the procedure. Then, they were shown 15 fifteen-word lists. The words were shown on a screen with a projector. The words were common one-syllable words. Each word was shown for 1 second with a 2-second interval between words. The experimenter read each word as it appeared.
After each list was done, the participants either saw a # or a number between 0 and 9. if they saw three #, the experimenter said “Write” and they wrote down as many words as they could recall in any order. if they saw a number, then they were to start counting from that number until the experimenter said, “Write.” The experimenter would either stop them after 10 seconds or after 30 seconds. To summarise, the conditions were:
- Immediate recall
- Delayed recall (10 seconds)
- delayed recall (30 seconds)
All participants were tested individually and the order of the reading of the lists was randomised.
Results: When asked for immediate recall, both primacy and recency effects were shown. With the 10-second distraction task, there was a significant reduction in the recency effect. In the 30-second delay condition, the researchers reported “no trace” of the recency effect.
Peterson and Peterson (1959)
Aim: To investigate the duration of STM. (hypothesis being that information that is not rehearsed is lost quickly from STM).
**Procedure*: A lab experiment was conducted with 24 psychology students. They had to recall trigrams (meaningless three consonant syllables). The trigrams were presented one at a time and had to be recalled after intervals of 3, 6, 9, 12, 15, or 18 seconds respectively for each trial. No two successive trigrams contained any of the same letters. After hearing a trigram, participants were asked to count backwards in threes of fours from a specified random digit number until they saw a red light appear (then they recalled the trigram). This is known as the Brown Peterson technique, which aimed to prevent rehearsal. The Iv was the interval between hearing the experiment say the trigram and the participant recalling the trigram. The DV was the number of trigrams correctly recalled by the participant after every trial. There was six trials in total.
Results: Their results showed that the longer each student had to count backwards, the less well they were able to recall the trigrams accurately.
- After 3 seconds, 80% of the trigrams were recalled correctly
- After 6 seconds this fell to 50%
- After 18 seconds less than 10% of the trigrams were recalled correctly.
Bartlett (1932)
Aim: To investigate how the memory of a story if affected by previous knowledge. (Can previous knowledge lead to distortion of memory?)
Hypothesis: Memory is reconstructive and that people store and retrieve information according to expectations formed by cultural schemas.
Procedure: Told a number British participants a Native American legend called “The War of the Ghosts”. For the participants, the legend, the concept, the names, etc. were all unfamiliar due to cultural differences. This made the story ideal to study the reconstruction of memory based on schema processing. The participants were allocated to one of the two conditions: repeated reproduction (asked to reproduce the story after short time and then repeatedly over a period), and serial reproduction (recall and repeat to another person).
Results: It was found that there was no significant difference between the way that the groups recalled the story. Participants in both groups changed the story as they recalled, distortion. It was found that 3 patterns of distortion took place: Assimilation (changing details to fit the participants norms in their culture), leveling (shortening the story as participants omitted details that were seen as insignificant), and sharpening (change the order of the story to make sense of it and added details/emotions. Basically, they overall remembered the main themes but changed the unfamiliar elements to match their own cultural expectations so that the store remained a coherent whole although changed.
Conclusion: The study indicates that remembering is an active process, where information is retrieved and changed to fit into existing schemas. This is done in order to create meaning in the incoming information. According to this study, humans constantly search for meaning. Based on his research, Bartlett formulated the theory of reconstructive memory (meaning that memories are not copies of experiences but rather a reconstruction).
Shallice & Warrington - case study of KF (1974)
Aim: To determine the interaction between the biological cause of amnesia and its impact on memory.
Bacground: KF was in an accident and suffered memory impairment, he had brain damage to his left parietal and occipital lobe.
Procedure: A longitudinal case study using different memory tests including remembering both verbal and visual information.
Results: KF could transfer information from STM to LTM. He suffered problems with STM of different types of information: Auditory was effected but not memory of visual information.
Conclusion: The results support the Working memory model showing that STM is more complex than the multistore model of memory proposed.
Baddeley & Hitch (1974)
Aim: To see if performance would be impaired when using two different parts of STM at the same time. (If not, this would support the working memory model.)
Procedure: Participants were asked to repeat numbers reading them out loud while doing a reasoning task.
Results: It was found that participants made few errors on either task, although the speed was slightly slower.
Conclusion: When ısing the ponological loop (repeating words with inner voice) at the same time as the central executive (problem solving), subjects used two different types of STM. This worked fine, supporting the working memory model.
Landry and Bartling (2011)
Aim: To investigate if articulatory suppression would influence the recall of a written list of phonologically dissimilar letters in serial recall.
Procedure: The participants were 34 psychology students. An independent samples design was used and the participants were tested individually. In the experimental group, the participants saw a list of letters they had recall while saying 1 and 2 at a rate of two numbers per second. The control group saw the list of letters but did not carry out the articulatory suppression task.
There were ten lists each consisting of a series of 7 letters randomly constructed from some letters (F, K, etc.) These letters were chosen because they don’t sound similar. The experimenter presented one letter series at a time and the participants recieved a blank sheet for answers. Before the experiment started, each participant viewed one practice list in order to understand the procedure. Each trial was scored for the accuracy of recall. The trial was correct if the letters were in the correct position. the experimenter then calculated the average percent correct recall for both groups.
Results: The scores from the experimental group were much lower than the control group (45% vs 76%). However, the standard deviations were nearly identical and pretty low. The mean percent of accurate recall in the control group was higher than the mean percent of accurate recall in the experimental group.
Conclusion: In line with the working memory model, articulatory suppression is preventing the rehearsal in the phonological loop because of overload. This resulted in difficulty in memorizing the letter strings for participants in the experimental conditions whereas the participants in the control condition did not experience such overload.
Bransford & Johnson (1972)
Aim: To determine if schema activation would result in a better understanding and recall of an ambigous text.
Procedure: There was 52 ğarticipants allocated to one of three conditions. The “no topic” group, 17 participants heard a passage with no additional information. The “topic after” group, 17 participants were told the topic of the passage after hearing it. The “topic before” group, 18 participants were told the topic of the passage before hearing it. They were all told that they would later be asked to recall the passage as accurately as possible and they were tested at the same time. they were also asked to rate their comprehension of the passage on a 1-7 scale.
The researchers had decided on “idea units” before the experiment. Each participant2s summary was independently scored by two judges, using the list of 18 idea units.
Findings: The researchers concluded that “prior knowledge of a situation does not guarantee its usefulness for comprehension. For prior knowledge to aid comprehension, it must become an activated semantic context.”
Brewer & Treyens (1981)
Aim: To investigate the role of schema in the encoding and retrieval of episodic memory. The basic assumption of theory schema theory is that individuals’ prior experiences will influence how they remember new information.
Procedure: There were 86 psychology students and they were seated in a room that was made to look like an office. The room consisted of items that would be expected to be seen in an office, as well as sime unexpected items (and some items were omitted that normally would be expected). The participants were asked to wait in this room until the researcher “checked that the previous participant completed the experiment.” The participants did not realize the experiment had already begun. All chairs except one had an object on them so all participants were guaranteed to have the same vantage point. After 35 seconds, the participants were called into another room and then asked what they remembered from the office. After, there was a questionnaire to ask if they expected this question and 93% said “No.”
30 participants carried out written recall and then verbal recognition. (asked to write and describe objects and given a booklet containing objects which they rated if they think it was in the room or not)
29 carried out drawing recall (given an outline of the room and asked to draw objects)
27 carried out verbal recognition only (were read a list of objects and asked whether they were in the room or not)
Results: It was found that participants that were asked to recall either by writing a paragraph or by drawing, they were more likely to remember items in the office that were congruent with their schema of an office. The incongruent items with their schema of an office were often not recalled. When participants were asked to select items on the list, they were more likely to identify incongruent items. However, they also had a higher rate of identifying objects which were schema congruent but not in the room. In both the drawing and recall condition, they also tended to change the nature of the objects to match with their schema.
Conclusion: It seems that schema played a role in both the encoding and recall of the objects in the office.
Greene (2011)
Aim: To investigate whether forcing participants to wait before making a moral decision will cause system 2 rather than system 1 thinking to determine moral decisions.
Procedure: Participants are given a story morally wrong story and then two arguments (a strong and weak) supporting the story. They are asked to rate the morally acceptibility to the arguments after.
Results: When subjects got time to think, their system 2 thinking was activated and therefore a clear difference was seen in their responses as the strong argument would be more valid than the weak. When responses were given immediately, there was no differences in responses, supporting that they used system 1.
Cox & Criggs (1982)
Aim: to see if matching bias was less commonly used to solve the Watson Selection Task when the task was more personally relevant.
Procedure: The participants were 144 psychology students. They were randomly allocated to one of six groups in order to counterbalance the experiment. Each group was given a workbook with 3 problems and they all had a different order of the questions. Each problem had 4 cards and a statemnt and they were asked to turn over the cards that proved the statement incorrect. One of the tasks was not personally relevant and only consisted of letters and numbers, the other was more relevant, and the last one was highly personally relevant.
Results: It was found that:
- The Abstract task: 3% solved correctly
- Intermediate: 43% solved correctly
- Memory cueing task: 60% solved correctly
They also found that when the participants were given the abstract task first, there was an increase in the use of matching bias in the other conditions.
Conclusion: It appears that when the task cued memory of past experience, a more rational approach was taken to choosing the cards. The more abstract and less relevant the task, the more likely that cognitive biases would be used to solve the problem.
Kruger (2003)
Participants rated a poem, a painting, and a suit of armour. The more time and effort participants believed that was put into produce it, the higher they rated the value of the piece.
Tversky & Kahneman (1973)
Aim: To investigate the anchoring effect on judgements.
Procedure: Partcipants saw a picture of a sequence for 5 seconds and estimated its product. The sequence that was in descending order was the high anchoring condition and the sequence in ascending was the low anchor condition.
Results: Median estimate of produce in the high anchor group: 2250. Median estimate of product in ascending group: 512. The results imply that seeing the high numbers in the beginning had an effect in the participants estimate.
Englich & Mussweiler (2001)
Aim: To investigate if the smple request for a certain length of a prison sentence would unduly influence the decision made by a judge.
Procedure: An independent samples design was used (which allowed the researchers to use the same case study for both high anchor and low anchor conditions). The sample was made up of 19 young trial judges in order to control the level of courtroom experiences (average of 9 months of experience). The participants were given a case of alleged rape and the prosecutor in one condition demanded a sentence of 2 months vs. 34 months. The case materials were priorly tested on senior law students which served as a pilot study. the average recommended prison term suggested by the law students was 17 months, which was used as a basis for determining the anchors. Participants were given the case materials and asked to read through and form an opinion. Afterwards, they were given a questionnaire. Half of the participants were told that the prosecutor demanded 34 and the other half 2 month sentence. they were asked what they though of the recommendation, what they would recommend, how certain they were (1-9), and how realistic the case was (1-9).
Results: The average rationg for rating for the realistic nature of the case was 7.17, with a standard deviation of 1.3. The judges’ certain about their responses, however, was not as strong, with an average rating of 4.53 and a standard deviation of 2.29.
When presented with a low anchor, the average sentence was 18.78 months, with a standard deviation of 9.11. In the high anchor condition of 34 months, the average sentence was 28.70 months, with a standard deviation of 6.53.
