Psychology Experiments and People Flashcards
Who tested the capacity of short term memory?
Jacobs (1887) - digit span experiment
What was the procedure of Jacobs digit span experiment?
Participants were presented with increasingly longer lists of numbers or letter which they had to recall in the right order (lab experiment)
What were the findings of Jacobs digit span experiment?
The average span for digits was 9.3 items
The average span for letters was 7.3 items
-stm capacity is 7+-2
Who tested capacity of sensory memory?
Sperling (1960) - sperlings sensory memory test
What was the procedure of Sperlings sensory memory test?
A 12 letter grid will flash onto the screen. (3 x 4 grid for a second).
•whole report procedure - participant asked to do free recall.
•partial report procedure - a tone would be heard (high, medium, low) each time corresponded to a line so participants asked to recall the letters on the row corresponding to the tone.
What were the results of the sperling sensory memory test?
- free recall- 4/5 letters recalled on average.
* partial report procedure- 3 out of 4 when recalling the row.
Who tested the duration of short term memory?
Peterson and Peterson (1959) - trigram experiment
What was the procedure of the Peterson and Peterson trigram experiment?
- researcher asked to recall out a trigram - 3 letters and 3 numbers.
- participants asked to recall after a delay increasing by 3 seconds each time.
- during the delay, participant were asked to count backwards in 3’s from the 3 digit number they were given.
- then they were asked to recall the trigram.
What were the findings of the Peterson and Peterson trigram experiment?
Participants on average, were 90% correct over 3 seconds, 20% correct after 9 seconds and only 2% correct after 18 seconds.
Who tested the duration of long term memory?
Bahrick at al (1975) - yearbook photos.
What was the procedure of bahrick’s yearbook photos experiment?
- ex high school students ages from 17-74 (400 people).
- a photo recognition test consisted of 50 photos, some from the participants yearbook.
- another way was to do a free recall test, they were asked to list the names they could remember of those in their graduating class.
What are the findings of Bahrick’s yearbook photo experiment?
- within 15 years of graduation, 90% accurate in identifying faces.
- (photo recognition) after 48 years, 70% accurate for photo recognition.
- (free recall) after 15 years, 60% accurate. After 48 years, 30% accurate.
What is the Capacity of long term memory?
There are no known limits to how much info long term memory can store
Who tested the encoding of long term memory?
Baddeley (1966) - words lists experiment
What was the procedure of baddeley’s short and long term word lists experiment?
•He used semantically similar words (meaning) and acoustically similar words (sounding) to test the effects on long term memory and short term memory.
What were the findings of baddely’s short/long term memory words lists experiment?
- participants had difficulty remembering acoustically similar words in STM but not LTM
- semantically similar words posed little problem in STM but led to muddled LTM
- this suggests that LTM is largely encoded semantically
- this suggests that STM is largely encoded semantically
Who studied variables affecting conformity?
Asch (1956)
What was the procedure of asch’s study on variables affecting conformity?
- participants were seated around a table to look at three lines of different lengths
- took turns to call out which of the lines was the same length as the ‘standard’ line
- confederates on 12/18 trials said the wrong answer
What were the findings of asch’s study on variables affecting conformity?
- 12 critical trials > average conformity rate was 33%
- 1/4 of participants never conformed
- controlled group were only wrong 1% of time
Who tested conformity to social roles?
Haney, Banks, Zimbardo (1973)
What was the procedure of the Stanford prison experiment?
- mock prison set up in the basement of Stanford uni
- 24 of most stable volunteers were randomally assigned to either prisoner or guard
- prisoners arrested unknowingly
- given uniforms
What were the findings of the Stanford prison experiment?
- over first few days, guards became increasingly tyrannical and abuse toward prisoners
- 5 prisoners had to e realeased early
- study terminated after 6 days (2 week plan)
What was the conclusion of the Stanford prison experiment?
Situational hypothesis (environmental factors within the prison would affect behaviour) was favoured
Who supported the working memory model?
Baddeley and Hitch (1976) - dual task performance
