Cognitive Case Studies

Aim: to test the "Levels of Processing" theory by seeing whether words processed at different levels would affect recognition of these words

Method:

• 24 participants
• Shown a series of 60 words through a tachistoscope 
• Asked a series of questions about the words
• Questions required either a structural, phonetic or semantic processing
• Participants were then asked to recognise words in a grid consisting of the original 60 words amongst 180 in total
• All 24 participants did all three levels of processing

Results:

• 17% of words recognised were at the structural level
• 36% of words recognised were at the phonetic level
• 63% of words recognised were at the semantic level

Conclusion:

• The deeper the processing, the deeper the recognition of words
• The recognition was greater for those words that were processed at a semantic level

Validity

• Controls were the number of words at each level, word length, time words displayed, same participants, random order for three levels 
• = good experimental validity, only the IV variable [types of processing] was affecting then DV
• DV [extraneous variable controlled] = not good ecological validity, task was artifical, could not relate to real life learning experiences

Reliability

• Hyde and Jenkins - 5 different levels, deep processing, participants rated pleasantness of words
• no different if memory was intentional or not
• high reliability 

Applications

• Good for revising

Overall

• Experiment support theory and experimental validity, IV directly affects the DV
• Good reliability as results were consistent and constant
• Not good ecological validity as cannot be related to everyday life

Strengths

• Led to experiments, most of which confirmed the superiority of 'deep' semantic processing

Weaknesses

• Concepts of depth is vague and cannot be observed, therefore cannot be objectively measured
• Does not explain how the deeper processing results in better memories

Aim: To investigate whether the wording of a question could alter a participant's recall. Consisted of two laboratory experiments, both examples of independent groups. 

Method

• 45 students
• 7 film clips of traffic accidents
• Ranged from 5 to 30 seconds
• Following each clip, students had to write an account of the accident they had just seen
• Asked questions, critical ones concerning speed of vehicle e.g. hit, smashed, contacted
• Independent variable = verb used
• Dependent variable = speed estimate by participants

Experiment One

Smashed 40.8

Collided 39.3

Bumped 38.1

Hit 34.0

Contacted 31.8

Experiment Two

Smashed = 16 said yes, 34 said no

Hit = 7 said yes, 43 said no

Control Group = 6 said yes, 44 said no

• Permanent altered memory due to post even information
• Show a significant effect of the verb in the q on the mis-perception of glass in the film

EXP 2 - Conclusions

• Post-event info permanently altered the eye-witness original mmemory of the event
• Police should be careful to ask leading questions when doing eyewitness interviews as these could change the witness' recall of the crime

Strengths

• Well controlled, high experimental validity
• Large samples more likely to be generalizable
• Application to real life in that it has important implications to police interviews

Weaknesses

• Not realistic in that the participants did not have direct involvement, lacks ecological v
• Arguable how representative students are as a generalisation

Aim: To investigate whether phonetic words were recalled when the context for learning and recall was the same, rather than if the context was differen - land and underwater. 

Method:

• Conducted in Scotland, groups of four
• 18 participants - 13 male, 5 female
• Repeated measures design
• 4 minute gap for divers to change context
• Task was to learn words from a list of 36

Results:

Land Land - 13.5

Land Underwater - 8.6

Underwater Land - 8.4

Underwater Underwater - 11.4

Conclusions:

• Forgetting occurs when context cues are absent

Extra Info

• First experiment had 4 minutes change in context
• Second experiment was conducted to see if the gap in changing of context could allow rehearsal
• No advantage from rehearsal
• No difference in results

Validity

• Experimental = high, set out to test what they did, not realised but realistic situations, lacked mundane realism
• Ecological = fairly high, realistic situation for divers, low = the way they learnt

Reliability

• Lang et Al showed similar findings - context/state cues do play a role in learning & recall
• High reliability, showed similar findings to Abernethy, standardised procedures

Generalizability 

• Only used 18 participants, fairly small sample size, used both sexes, not specialised for one gender. Difficult to generalise because contexts e.g. underwater would not realistically/normally be used

Applications - future to ensure good recall/learning, accurate eye witness statements

Strengths

• Highly controlled experiment makes it more reliable
• The only variable that changed is the IV
• All of the divers were in the same wet and cold state for 4 minutes between land and underwater

Weaknesses

• Diver could rehearse

Aim: to test retroactive interference by comparing recall of a word list after learning similar or dissimilar information.

Method:

• 12 participants
• Repeated measures experiment - counterbalanced to avoid order effect
• Task of words to learn
• 10 words to learn
• Followed by six other tasks

Results:

• Rest for 10 minutes = 4.5
• 3 digit numbers = 3.7 
• Nonsense syllables = 2.6
• Unrelated words = 2.2
• Antonyms = 1.8
• Synonyms = 1.3

Conclusion

• Similar information competes for memory space within old memory
• Supports retroactive interference

Strengths

• Well-controlled study
• Avoided confounding variable
• IV affected the DV

Weaknesses

• Small sample of participants
• 12 participants but tested 6 times
• Difficult to generalise, very small sample size