STM and LTM Flashcards
What are the differences between the LTM and the STM
STM -
-Encoded acoustically,
-Capacity = 7 +- 2 bits of information
-Duration = 18-20 seconds
LTM -
-Encoded semantically
-Capacity = unlimited
-Duration = essentially a lifetime
Who did research into the encoding of the different types of memory
Badely (but a diffent one)
What experiment did Badley do to test the encoding of Short and Long term memory
He had participants learn words that were either acoustically similar or dissimilar, or semantically similar or dissimilar. He found that acoustically similar information was easier to mix up when being recalled a short time after encoding, showing STM is acoustically encoded. When recalled a long time after encoding semantically similar words were recalled with less accuracy, showing the LTM is encoded semantically
Who discovered the ‘magic number’ for memory
George Miller
What did George Miller discover
That the magic number for short term memory recall was 7+- 2 bits of information. As part of this he noted that people could count up to 7 dots when they were flashed on screen but not many more
How can short term memory be improved
George Miller found that people could remember more if they chunked the information, meaning grouping the information into sperate parts
Who did research into the duration of Long Term Memory using yearbook photos
Bahrick
What study did Bahrick do into the duration of LTM
Showed graduates photos from their high school yearbook with a group of names, and asked them to name the person in the picture. Bahrick found that 70% were able to correctly match the names and faces 48 years after graduating.
What conclusions did Bahrick draw from his study into LTM
Bahrick concluded that the duration of LTM was essentially a lifetime, and that as information used 47 years ago was still present in the majority of participants memories, the capacity of LTM must also be unlimited, or it would have been replaced with more recent information
How did Peterson and Peterson conclude that the duration of STM was 18-20 seconds
They had people read a line of characters, then gave them a distraction task to ensure they didn’t process the info. After a range of intervals they asked the participants to write doen the characters, with recall falling off after the 18 second mark
Who did a study into the duration of STM
Peterson and Peterson
What is an issue with research into the capacity of STM and individual differences
There may be individual differences which influence capacity. Jacobs, who ran one of the earliest psychological tests to assess STM capacity, found that recall improved steadily with age, with the mean for 8 year olds being 6.6 digits whereas for 19 year olds it was 8.6 digits. This could be due to brain changes or development of memory strategies like chunking. Suggests STM may not be fixed but individual differences, like age, have an effect
Who did one of the earlies psychological tests into STM
Jacobs
Why might research onto LTM and STM have low ecological validity
The conditions used are often entirely artificial. Often studies include memorising meaningless strings of characters, such as in Jacobs study. This doesn’t refect our everyday experiences or memory activities. However it could be argued that we do actually have to memorise things like phone numbers or postcodes, thus the tasks may retain relevance to everyday experinces
Why might splitting encoding into semantic or acoustic encoding be too simplistic
Frost found that long term recall is related to visual as well as sematinc categories, while Nelson and Rothbart found evidence of acoustic encoding in the LTM. Therefore simplifying encoding of memory into semantic or acoustic may be reductionist (not convinced this is reductionism) as it simplifies complex memory into a simple dichotomy
Who found evidence that recall is related to visual as well as semantic categories
Frost
Who found evidence that long term recall is related to visual as well as semantic categories
Nelson and Rothbart
Who repeated Peterson and Peterson’s study with auditory tones
Reitman
