Memory

Memory

1. Coding, capacity, duration

   • Coding= The format that information is stored as in each memory store
   • STM is coded acoustically
   • LTM is coded semantically
   • Baddeley (1966) conducted a study that found more mistakes were made when learning acoustically similar words straight after learning them, and more mistakes were made when recalling semantically similar words 2 minutes after learning them
   • Capacity=The amount of information that can be stored in each memory store at any one time
   • Miller suggested that the capacity of STM is about 7 +/- 2 chunks, and we use 'chunking' to help us remember more information
   • Jacobs suggested the mean letter span was 7.3 and the mean digit span is 9.3
   • Duration= The amount of time that information can be held in each memory store
   • The duration of the STM is thought to be about 3-18s (Peterson and Peterson 1959) when 24 psychology students had to recall trigrams at different time intervals
   • The duration of the LTM is thought to be up to a lifetime. Bahrick et al in 1975 got 396 people betwen 15-46 years of graduating to recall the names of people from their yearbook based off their photos. He found that accuracy decreased form 90%-70%

2. Types of long term memory

   • Semantic memory refers to memories related to the world and associated knowledge, so essentially facts. They must be consciously recalled.
   • Episodic memory refers to memories of personal meaning including details surrounding them. They must be consciously recalled.
   • Procedural memory refers to memory of performing skills and tasks and they can be unconsciously recalled.
   • Proposed by Tulving as he thought the MSM was not detailed enough
   • Clive Wearing had a virus that left him with damaged semantic and episodic memory but his procedural memory remained the same
   • Peterson et al showed the semantic memories are recalled from the left prefrontal cortex and episodic memories are recalled from the right
   • Belleville et al noted mild cognitive impairments mostly effect episodic memories

3. Multi store model of memory

   • Designed by Atkinson and Shiffron
   • Sensory register ---> attention ---> STM---> Maintenance rehearsal loop---> LTM
   • STM= acoustically coded (Baddeley), duration of 3-18s (Peterson and Peterson), capacity of 7+/- 2 chunks (Miller)
   • LTM= semantically encoded (Baddeley), lifetime duration (Bahrick et al), unlimited capacity

4. Explanations for forgetting

   • Retroactive interference= New memories block old
   • Proactive interference= Old memories block new
   • McGeoch and McDonald proved retroactive interference in 1931 when participants had to recall a different list of words after a new list. Those who learned synonyms had an average of 3.1 fewer correct items than the control group
   • Postman (1960) mimicked McGeoch and McDonald's experiment
   • Baddeley and Hitch got rugby players to recall the total number of games in the season as well as their last game, they found that the most important factor in remembering the game was the number of games they had played all season

5. Working model of memory

   • Developed by Baddeley and Hitch
   • Central executive has a very short duration and capacity. It assigns tasks to slave systems.
   • Phonological loop=processes auditory information, articulatory process stores words you hear
   • VSS= combines visual and spatial information, and helps us to form a complete picture in our heads. It has a capacity of a bout 4-5 chunks and is divided into the inner scribe and the visual cache
   • Episodic buffer= Integrates all types of data processed by other stores, so is the storage component of the CE and a link between the STM and LTM
   • KF was in a motorbike accident, his verbal information was damaged but visual information wasn't
   • Baddeley (1975) proved exsistance of the PL, could store more words that are single syllable than multi syllabic (word length effect)