Cognitive Studies

HM Milner: 1966

HM Milner: 1966

HM Milner (1966) 

Aim: To better understand the effects that the surgery had on patient HM.  

Procedure: This study was a longitudinal case study and used several methods of data collection. It closely followed patient HM, whom was hit by a cyclist at age 7 and suffered severe epileptic attacks, which by age 27 controlled his life. Tissue was removed from the medial temporal lobe on both side of HM’s brain. Observations were made about Milner using psychometric testing (IQ tests), direct observation, interviews with HM and family members, cognitive tests (memory recall tasks and learning tasks) and eventually MRIS.  

Results: The memory systems in the brain constitute a highly specialized and complex system. The hippocampus plays a critical role in converting memories of experiences from short-term memory to long-term memory. However, researchers found that short-term memory is not stored in the hippocampus as HM was able to retain information for a while if he rehearsed it. Since HM was able to retain some memories for events that happened long before his surgery it indicates that the medial temporal region is not the site of permanent storage but rather plays a role in the organization and permanent storage of memories elsewhere in the brain. Implicit memory contains several stores - for example, procedural memory, emotional memory and skills and habits. Each of these areas is related to different brain areas 

Strengths:  

• Longitudinal, so change was observed over time  

• Method triangulation used 

• High ecological validity 

• HM was protected from harm, remained confidential, and gave consent 

Weaknesses:  

• Cannot be replicated because case study  

• Retrospective, so limited data on abilities prior to surgery 

Brewer and Treyens (1981)

Aim: to investigate the role of schema in encoding and retrieval of episodic memory 

Procedure: Participants seated in a room made to look like an office. The room consisted of objects that were typical of offices and there were some that one would not typically find in an office - like a skull a toy top, a piece of bark, a screwdriver. Each participant was asked to wait in the office. The participant didn't realize that the study had begun. The participants were asked to have a seat. All the chairs except for one had objects on them. So, it was guaranteed that all participants would have the same vantage point in the office. The researcher left the room and said that they would return. After 35 seconds the participants were called into another room and then asked what they remembered from the office. When they finished the experiment, they were given a questionnaire. Some participants carried out written recall and then verbal recognition, some carried out drawing recall, and others verbal recognition only. 

Results: When participants were asked to recall either by writing or drawing, they were more likely to remember items that were congruent with their schema of an office. Items that were incongruent with their schema of an office were not often recalled. When asked to select items on the list, they were more likely to identify the incongruent items; They also had a higher rate of identifying objects which were schema congruent but not in the room. In both the drawing and the recall condition, they also tended to change the location of the objects to match their schema. (Like, the pad of yellow paper that was on a chair was remembers as being on the desk.)  It appears that schema played a role in both the encoding and recall of the objects in the office

Strengths: 

• The research produced both quantitative and qualitative data in order to provide a richer understanding of the role of schema 

• They had concent from the participants 

Weakness: 

• ethical concerns about the deception used in the study 

• There is no way to verify the schema of the participants prior to the experiment, 

Tversky & Kahneman (1974) 

Aim: demonstrates the power of anchoring bias by using a mathematic problem 

Procedure: High school students were used as participants. Participants in the “ascending condition” were asked to quickly estimate the value of 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 in five seconds. Those in the “descending condition” were asked to quickly estimate the value of 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1.  

Since we read from left to right, the researchers assumed that group 1 would use "1" as an anchor and predict a lower value that the group that started with "8" as the anchor. The expectation was that the first number seen would bias the estimate of the value by the participant. 

Results: The researchers found that the median for the ascending group was 512; the median for the descending group was 2250. The actual value is 40320 

Strengths: 

• easily replicated, allowing to test the reliability of the results 

• highly controlled and has high internal validity 

Weakness: 

• low ecological validity. The situation is very artificial 

• Independent samples design so, participant variability may have played a role in the results 

Landry and Bartling

 Landry and Bartling (2011) 

Aim: investigate if articulatory suppression would influence recall of a written list 
of phonologically dissimilar letters in serial recall. 

Procedure: There were ten lists each consisting of a series of 7 letters randomly constructed from the letters F, K, L, M, R, X and Q. The experimenter presented one letter series at a time. They received an answer sheet with seven blanks in each row. The participants received instructions to repeatedly say the numbers '1' and '2' at a rate of two numbers per second from the time of presentation of the list until the time they filled the answer sheet. This was repeated ten times. Before the experiment started, each participant viewed one practice list to become acquainted with the procedure. In the control group, the experimenter showed participants a printed list for five seconds, instructed them to wait for another five seconds, and then instructed them to write the correct order of the letters on the answer sheet as accurately as possible.  

Results: The experimenter calculated the average % correct recall for both groups. The scores from the experimental group were much lower than the scores from the control group. The mean % of accurate recall in the control group was 76% compared to a mean of 45% in the experimental group. The standard deviations were nearly identical. A T-test was calculated and found a significant difference of p ≤ 0.01. The results supported the experimental hypothesis. In line with the Working Memory Model, articulatory suppression is preventing 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. 

Strengths  

• Study is well-controlled 

• High level of internal validity. 

• cause-and-effect relationship can be determined 

• Easily replicable, so it can be retested, and the findings can be considered reliable. 

Weaknesses: 

• Nature of the study is artificial and so it lacks ecological validity

Kulkofsky et al (2011) 

Aim:

Schaefer et al (2011) 

Mueller and Oppenheimer (2014)

Aim: Investigate whether processing notes in your own words helps the learning process better than taking notes on the computer, regardless of how “complete those computer notes may be.” 
Procedure: 

• Given either a laptop or pen & paper – instructed to take notes on 4 lectures - tested in 1 week (no studying unless in the study condition where they studied 10 minutes before the exam) 

• Factual vs conceptual test questions 

Results: 

• Both the longhand and laptop conditions: poorly on factual knowledge but fairly well on conceptual knowledge without studying 

• Significant difference when studying between longhand and laptop – longhand did significantly better 

Strengths and Weaknesses:

• highly standardized, replicated, reliable, low ecological validity (possibly), participant variability, high standard deviation, low internal validity