1. Since list C was recalled the worst, it appears that there’s semantic STM Baddeley (1966)
Encoding in confusion in LTM. Therefore, LTM tends to be encoded on a semantic basis.
The Multi-Store Model
Short-Term Memory Atkinson and Shiffrin (1969) Long Term Memory
Three Separate Stores For Memory. (Sensory, Short-Term and Long-term Memory)
Information Is Encoded Acoustically Information is Encoded
(Through Sound) Encoding in STM and LTM by Baddley (1966)
Semantically
Aim: To investigate how information is encoded in STM and LTM memory.
Procedures: Participants were present with four word lists which are either: (Through Meaning)
List A: acoustically similar (cat, mad, sat, sad)
List B: acoustically dissimilar (pen, day, cow)
List C: semantically similar (big, huge, great)
List D: semantically dissimilar (old, late, thin)
75 participants heard one list repeated four times. Immediately after this (to test STM) and 20 minutes
later (to test LTM) , they were given a list in both occassions that contained all the words but in the
wrong order. There task was to rearrange the words in the correct order.
Findings: Those participants given list A (acoustically similar) performed the worst (recall 10%). Recall
for the other lists were comparatively good (60-80%) .
Those participants given list C (semantically similar) performed the worst. Recall for the other lists was
Capacity is on average 7 items comparatively good (70-85%)
(+/-2) Has Unlimited Capacity
Conclusion: Since List A was recalled the worst, it would appear that there’s acoustic confusion in
STM. Therefore, STM tends to be encoded on a acoustic basis.
Since list C was recalled the worst, it appears that there’s semantic confusion in LTM. Therefore, LTM
tends to be encoded on a semantic basis.
Capacity in STM Jacobs 1887
Duration in LTM by Bahrick
Aim: to investigate the capacity of STM
Procedures: Jacobs reads aloud lists of either et al (1975) Duration a long time…
letters or numbers. He gradually increased the
but declines a little over time.
Duration less than 30 seconds length of these lists until participants could only
successfully recall them 50% of the time.
Jacobs used a wide range in his sample. Aim: To investigate the existence of very long
Findings: STM capacity for numbers was 9, term memories (VLTM) using real-life
whereas for letters it was 7 memories.
Procedures: 400 participants ranging in age
After 18secs, Conclusion: STM has a limited capacity of
from 17 to 74 were asked to remember the
fewer than 10% between 5 and 9 names of classmates from their high school (a
recalled free recall task). They were also shown a set of
correctly. Duration in STM (1959) photos and a list of names, some of which
were of their ex-school friends. They had to
After only Aim: To investigate the duration of STM when no rehearsal is allowed.
identify their ex-school friends (a recognition R e h e a rsa l
Procedures: Participant were read a nonsense trigram (three
3secs, 80%
consonants with no meaning e.g.LTB). Immediately after this, task). Loop
recalled participants had to count backwards in threes starting from a very Findings: Those who’d left high school within
correctly. large three digit number (e.g. 576) for a specified period of time. This the previous 15 years recalled 90% of the
time period was called a retention interval and varied from 3-18
faces and name in the recognition task. Those A tte n t io n
seconds. The counting backwards was called the distracter task. It
was designed to prevent rehearsal of the trigrams. At the sound of a who’d left 48 years previously recalled 80% of
tone, participants had to recall the trigram. the names and 70% of faces. Free recall of the
Findings: Approximately 90% of the trigrams were recalled after a 3
names was comparatively poor.
Recall got progressively second retention interval. Only about 10% were recalled after 18
seconds. Letters had to be exactly in the same place in the recalled Conclusion: people do possess VLTM (very
worse as the delay trigram as in the original. long-term memories), although these decline a
S e n so ry S h o rt T e rm Lo n g T e rm
Conclusion: Without rehearsal, the duration of STM is very short little over time.
grew longer! M e m o ry
indeed (less than 18 seconds)
M e m o ry M e m o ry
…Created by Naziya Ali…