3. types of long term memory

who proposed the types of LTM

• tulving was one of the first cognitive psychologists to realise the MSM view of LTM was too simplistic and inflexible

• he proposed there are three LTM memory stores containing different types of information

types of LTM

• episodic

• semantic

• procedural

episodic memory

a LTM store for personal events

• they are time stamped meaning you remember when they happened, and they store information about how events relate to each other in time

• different elements ie people, places and behaviours are interwoven to produce a single memory

• requires a conscoius effort to recall memories - this is done quickly but are still aware you are searching for the memory

semantic memory

a LTM store for our shared knowledge of the world

• likened to a combination of an encylopaedia and a dictionary

• includes knowledge of things such as the meaning of words, how to apply to university

• memories are not time stamped

• semantic knowledge is less personal and more about facts we all share - it contains an immense collection of material which is constantly being added to

• according to tulving it is less vulnerable to distortion and forgetting than episodic memory

procedural memory

a LTM store for our knowledge of how to do things

• recall these memories without conscious awareness or much effort (eventually)

• may find it hard to explain these skills to someone else

evaluation

1. real world application

2. clinical evidence (& counterpoint)

3. conflicting neuroimaging evidence

4. more complex

real world application

• understanding memory types helps treat memory loss

• as you age, memory loss is experienced, but seems to be specific to episodic memory - belleville et all trained older participants to improve their episodic memory which led to better recall than a control group

• suggests episodic memory can be targeted for improvement, showing practical benefits, which demonstrates how distinguisihing memory types can aid in treatment development

clinical evidence

• case studies of HM and Clive Wearing show distinct memory stores

• episodic memory in both men was severley impaired due to brain damage (caused by an operation and infection respectively) but their semantic and procedural memories were relatively unaffected

  SEMANTIC - understood meaning of words, eg HM could not recall stroking a dog half an hour earlier but did not need the concept of ‘dog’ explained to him

  PROCEDURAL - both knew how to walk and speak, and Clive Wearing (professional musician) knew how to read music and play the piano

• suggests LTM is divided into separate stores, as one type can be damaged while the others remain unaffected

counterpoint

• brain injury studies have limitations in understanding memory

• there is no control over predamage memory since brain injuries vary unpredictably meaning researchers cannot compare before and after conditions, making it challenging to measure memory loss accurately

• challenges reliability of clinical studies in identifying distinct memory stores

conflicting neuroimaging evidence

• brain scan studies do not always agree on memory location

• buckner & peterson 1994 linked semantic memory to the left of the prefrontal cortex, while tulving et al 1994 linked the left prefrontal cortex with encoding of episodic memories

• if different studies show different brain areas, the exact location of memory types remains uncertain, weakening neurophysiological support for distinct memory types

more complex

• episodic and semantic memory may be more closely linked than previously thought

• tulving 2002 suggested episodic memory is a subset of semantic memory, while hodges & patterson 2007 found alzheimers patients could have impared episodic memory but intact semantic memory

• suggests the boundaries between episodic and semantic memory are not absolute, questioning the strict separation of memory types and suggesting a more complex relationship