Types of long-term memory

LTM divided into 2 main types: explicit (or declarative) or implicit (or procedural) memory. Distrinction b/ween knowing that + knowing how. Episodic + semantic - knowing that. Procedural - knowing how.

Knowing that. Concerned w/ personal experiences, recollection of eg first day at school, family holiday etc. May recall time + place of events as if there. 

May also recall context eg what happened just before or after, why you were there. May also recall associated emotions felt at time.

3 elements: specific details of evennt, context + emotion.

Knowing that eg know people of certain age go to school, 2+2=4. Knowledge about world shared by everyone rather than personal kind of knowledge classed as episodic.

May relate to thinks eg functions of objects, may relate to what behaviour appropriate eg social customs, + may relate to abstract eg maths + language.

Generally begin as episodic b/c acquire knowledge based on personal experiences. Gradual transition from episodic to semantic - memory slowly loses association to particular events - info can be generalised as semantic memory. Sometimes, people continue to have strong recollection of when + where learned particular fact.

Concerned w/ skills eg knowing how to tie shoelace, how to drive etc. About remembering how to do something.

Typically acquired through repetition + practice - implicit, unlike semantic + episodic. Less aware of these memories b/c become automatic. If try to think about them too much, prevents you from acting them out. Attention to step-by-step procedure disrupts well-learned, automatic performance.

Important procedural memories are automatic so can focus attention on other tasks while performing everyday tasks.

Evidence from brain scans - shows diff areas of brain active when diff kinds LTMs active. Episodic associated w/ hippocampus + other parts of temporal lobe where hippocampus located. Also associated w/ activity in frontal lobe. Memories of diff elements of particular event may be distributed in other brain areas but all connected by hippocampus - one episode. Semantic - temporal lobe. Procedural - cerebellum, involved in control of fine motor skills as well as motor cortex. Basal ganglia + limbic system also involved in this type learning.

HM - ability to form new LTMs affected by destruction of hippocampus, but retained pre-existing LTMs - simplification. After surgery, could form new procedural memories, but not episode or semantic eg able to learn mirror-drawing (Corkin, 2002), but no memory he had learnt this.

Priming - describes how implicit memories influence responses person makes to stimulus. Research shown priming controlled by brain system separate from temporal lobe that supports explicit memory -> suggestion 4th type LTM - perceptual-representation system (PRS) related to priming - automatic enhanced recognition of specific stimuli. Spiers et al (2001) - 147 amnesia patients - all cases, procedural memories + PRSs intact, but 2 other systems not - supports 2 kinds of implicit memory not affected by amnesia.

Problems w/ evidence from brain damaged patients (shown in WMM). 

Difficulty w/ studies of amnesiacs, inc HM, diff to be certain of exact part of brain affected until patient died. Most studies on living patients. Damage to particular area doesn't necessarily mean area responsible for behaviour - may be acting as relay station. Malfunction of relay station impairs performance.