Memory

Memory

1. STM Encoding

   • Procedure: Participants shown lists of printed letters, write down as many as you can remember.
     • Findings: mistakes participants made tended to be a result of mixing sounds of letters rather than their appearance e.g. participants mixed up B and V because they sound similar. They did not confuse F and E even though they look similar.

2. STM Capacity

   • Procedure: Read out lists of digits to participants and asks them to repeat them in same order. Make lists longer and longer
     • Findings: Participants recalled 5-9 digits

3. STM duration

   • Procedure: Participants given trigrams (set of three letters) which they were asked to recall in order after delay of 3,6,9,12,13,15,18 seconds. To prevent rehearsal participants had to count back in 3's from random 3 digit number
     • Findings: longer participants were asked to count backwards, fewer set of letters able to recall. percentage of recall: 3 sec=80% 6 sec=50% 18 sec=10%

4. STM chunking

   • Procedure: partcipants presented with multi word phrases. These phrases ranged from single word to 10 words long. Each multi word phrase was classified as a chunk
     • Findings: If chunking went beyond single words than the capacity of the STM for the phrases dropped. 2 word phrases=average

5. LTM Duration

   • Procedure: 392 American ex high school students of various ages. Recall tested in three ways:
     • Free recall test: participants were asked to list the names of as many of their former classmates as possible
     • Photo recognition test: participants were shown photos and asked to recall the names of the people shown
     • Name recognition test: participants given names and asked to match them to a photo of class mate
     • Findings: within 15 years of leaving school-participants could recognise about 90% of names and faces (name recognition test) participants 60% accurate on the (free recall test). After 48 years of leaving school: participants could recognise about 75% of names and faces, participants 30% accurate on free recall test.

6. LTM Encoding

   • Procedure: participants asked to learn 10 words with distinct meanings (cold, wet, hot) and 10 words with similar meaning (e.g. huge, big, broad). Participants recall words after timed delay.
     • Findings: most confusion from similar words compared to the words that were semantically distinct. Participants recalled more of the words with distinct meanings. Semantic encoding of information in LTM is the main encoding system used

7. Multi Store Model

   • Atkinson and Shiffin created the MSM to prove that the brain had two different types of memory; short term memory and long term memory
     • Model begins with the stimulus input, this can also be known as one of the five senses, see hear, touch, taste and smell.
       • The sense is then passed onto the sensory memory which has a brief duration, a large capacity and multiple ways of encoding.
         • Once you recognise and pay attention to the sensory memory the information is stored in the STM. The STM has a capacity of 7+ or -2 items, a duration of 8-20 seconds and the main type of encoding is semantic.
           • After you have rehearsed the information in the short term store it is then stored in the long term store. The LTM has an unlimited capacity, can hold information for up to a lifetime and its main type of encoding is semantic.
   • Serial position effect supports MSM
     • Participants were asked to study a list of words and try to recall the words in order.
       • Participants mostly recalled the words at the beginning and end of the list. This shows the primacy and recency effect and supports the MSM because it shows we have two types of memory.
   • Strengths
     • HM study supports MSM. HM was a young boy suffering from epilepsy that had parts of his brain removed.
       • The findings were that his LTM was effected but his STM wasn't.
     • contributed greatly to memory research and helped other psychologists in other studies.
   • Weaknesses
     • Too simple as it doesn't take into account the complexity of the human brain.
     • relies alot on rehearsal. Studies have proved that rehearsal isn't the only way to transfer information to the LTM. The flash bulb memory is another way information can enter LTM. The idea is that we remember events that may be funny or sad events when something significant happened and this goes straight into your LTM wihout any rehearsal.
     • KF study: brain damage from motocycle accident. Findings were that his STM was affected but his LTM wasn't. However impairment was mainly for verbal infoirmation, his memory for visual information was largely unaffected. This shows sepearate components to the STM. MSM says a working STM is needed to transfer memories to the LTM.

8. Working Memory Model

   • Central executive
     • Directs attention to particular tasks. It controls the other systems (slaves) by determining how resources will be allocated.
       • Decides how attention is directed e.g. two activities sometimes come into conflict such as driving a car and talking.
         • Allocates resources to one of the sub stores (phonological loop or visuo spatial sketchpad)
           • Has storage capacity unlimited
   • Phonological loop
     • controls spoke en written material.
       • Subdivided into phonological store (inner ear) and the articulatory process (inner voice)
         • The phonological store (inner ear) holds information in speech based form (spoken words) for 1-2 seconds
           • Spoken words enter the store directly. Written words must be converted into an articulatory (spoken) code before they enter phonological store
             • Inner voice: written words enter indirectly after being converted sub vocally e.g. when reading a book. Rehearsal takes place here used to rehearse and store verbal information from the phonological store
     • limited capacity so need rehearsal
   • Visuo-spatial sketchpad (inner eye)
     • Deals with visual and spatial information. Plays important role in helping keep track of where we are in relation to other objects as we move through our environment
     • The sketchpad also displays and manipulates visual and spatial information held in the LTM e.g. spatial layout of house held in LTM
     • briefly storing visual and spatial information which can be maintained by rehearsal as it has limited capacity.
     • create and manipulate visual and spatial image e.g. choice of routes you want to take
   • Strengths
     • Researchers today generally agree that STM is made up of a number of components or subsystems
       • Explains more than MSM as it makes sense of a range of tasks: verbal reasoning, comprehension, reading, problem solving and visual and spatial processing
         • Doesn't emphasise rehearsal like STM does
           • Supported by KF study: KF's impairment mainly verbal information, memory for visual informration largely unaffected. Shows separate parts to STM.
   • Weaknesses
     • Little evidence for how central executive works and what it does. Capacity for central excutive never measured.
       • Doesn't account for LTM, only STM
         • Does not explain changes in procesing ability that occur as the result of practice or time
           • Does not account for musical memory, shows you can listen to music while doing another task. This shouldn't be possible according to WMM as you can't listen to something while doing another task due to STM being an unitory store