MSM and Types of Long- Term Memory

• The MSM of memory was proposed by Richard Atkinson and Richard Shiffrin (1968-1971)
• There is a system for how memories are made and stored in the MSM: the sensory register, STM and LTM
• Diagram of MSM

  Linked by process that enables information to flow from each store

  
• The sensory register (SR) is where all sensory information from the environment passes into or is held.
• The coding of the sensory register is modality specific: ionic memory is for visual information and echoic memory is coding for acoustic information
• The sensory register has a high capacity
• The duration of the sensory register is a few seconds
• To transfer information from the sensory register to the STM attention must be paid
• Information that enters the short-term memory (STM) is used for present and immediate tasks e.g. for following directions or recalling someone's name immediately after learning it
• Information entering the STM is typically acoustic (Baddeley 1966)
• Capacity of the STM is around 5-9 items (Jacob’s 1887)
• Duration of the STM is around 18 seconds (Peterson and Peterson 1959) meaning it is a temporary memory store
• For information to be passed from the STM to the LTM is through elaborate rehearsal (deeper processing)
• For information to stay in the STM maintenance rehearsal is needed ( surface level repetition)
• Long-term memory is a permanent memory store of past events or items
• To recall information that has passed into LTM it must be accessed and transferred to STM, this is known as retrieval
• Information in LTM is coded semantically (based on meaning) Baddeley 1966
• The capacity of the LTM is potentially unlimited ( Linton 1975)
• The duration of the LTM is thought to be a lifetime ( Bahrick et al 1975)
• Some items in the LTM are prone to being forgotten: memories displaced from the STM, some LTMs may be unavailable due to resistance of retrieval and LTM decay
• Strengths of the MSM: the studies done about the MSM are all controlled lab studies suggesting there is a clear distinction between the STM and LTM. Additionally case studies (HM had hippocampus removed) strengthens the idea that the brain uses separate regions for STM and LTM
• Weaknesses: the MSM may be too simplistic as other research suggests the STM and LTM are made up of more than one store. Additionally, much of the research into the MSM includes artificial tasks and lacks ecological validity meaning there are limited real life applications to memory.
• Episodic memories are linked to certain events or experiences in a persons life and are generally time stamped. They are declarative and autobiographical. Additionally, able to be consciously inspected.
• Procedural memories are ways of knowing how (muscle memory) to do things or carry out tasks. These are non- declarative. Additionally, not available for conscious inspection.
• Semantic memories are general knowledge and facts that are accumulated. These are not personal or emotive memories. They are declarative but not attached to a time or place that they are learnt. Able to be consciously inspected.