MSMM case studies Flashcards
Baddelley 1966
Gave a 4 groups of participants a different list of words to remember: group 1, acoustically similar, group 2 acoustically dissimilar, group 3 semantically similar, group 4 semantically dissimilar .
Participants did worse with acoustically similar words.
Conclude and evaluate baddelley
Suggests that information is coded semantically in LTM and that we code acoustically in STM.
Artificial stimuli- cant generalise as it has no world meaning
Margaret and Lloyd petersen (1959)
Tested 24 undergraduate students took part in 8 trials, each student was given a trigram for each trial and was also given a 3 digit number. Then the student was told to count backwards from the three digit number to prevent mental rehearsal. Each trial lasted longer than the other, this is the retention interval.
The lower the retention interval the higher percentage of correct responses.
Conclude and evaluate Margaret and Lloyd petersen (1959)
C- Duration of short memory is limited to 30 seconds without rehearsal.
E- because they were using trigrams, people were getting confused with different trigrams.
Participants knew their memory was being tested, when participants don’t know, STM is limited to 4 seconds.
Jacobs digit span
Jacobs developed a technique to measure a digit span. The researcher gives the P 4 digits to say out loud and if they are correct they have 5 digits and so on until the P cannot recall the order correctly.
Jacobs found that the mean span for all digits across all participants was 9.3, the mean span for letters was 7.3.
George Miller; chunking
Miller noticed things come in 7s; 7 notes on a music scale, 7 days of the week and 7 deadly sins and so on… This suggests that the span/capacity of STM is about 7 items +or- 2 (7+-2)
However miller noticed that people can recall 5 letters and 5 words via chunking.
Conclude and evaluate the two studies (chunking and span)
- STM has a limited capacity
- Digits scored a higher mean of 9.3 comparing to letters scoring a lower score of 7.3 meaning its easier to remember digits.
- Eval- Lacing validity, conducted a long time ago back then research often lacked adequate control e.g distraction for participants leading to low performance.
- not so many chunks, Cowan said that the capacity of STM was only 4 chunks.
Henry Bahrick (1975) duration of LTM
Ohio american state 365 ages between 17 and 74. High school year books were obtained from participants who went to the same school (all of them). recall was tested through pictures and names from yearbook. Participants before 15 years of graduation recalled 90% of photos correctly and 48 and above recall declined to about 70%.
Conclude and evaluate Henry Bahrick’s study
- Free recall was worse than recognition
- LTM can last a very long time
(eval) high external validity- real life studies were studied, when studies on LTM was conducted with meaningless pictures, LTM was lower but with meanfull pictures LTM was high. Confoundng variables were not controlled.
Tulving
-three different types of LTM he made, semantic, procedural, episodic. Episodic is time stamped.
Eval- neuro imaging (participants to use the PET scanner so different types of memory come up in different parts of the brain)
Clinical evidence- Clive wearing
Real life application- use these results to hell in real life, people who have cognitive impairment can be trained to recover and improve procedural memory. Test with a trained group and control group, trained group did better.
Problems with clinical evidence- lacks internal control as they’re not controlling extraneous variables.
Cohen and squire- episodic and semantic are together in declarative memory but prodigal is in non declarative so they belive that their is two different types of LTM
