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MEMORY

MEMORY. Learning objectives. be able to define memory understand the nature of the sensory information store, short term memory and long-term memory understand the differences between declarative and non-declarative long-term memory know the brain regions involved in memory

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MEMORY

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  1. MEMORY

  2. Learning objectives • be able to define memory • understand the nature of the sensory information store, short term memory and long-term memory • understand the differences between declarative and non-declarative long-term memory • know the brain regions involved in memory • know the main developmental factors involved in memory

  3. Memory • Capacity that permits us to benefit from past experience (Tulving, 1985) • Divided into sensory information store (SIS), short-term memory (STM) and long-term memory (LTM) • Motor memory is the ability to consistently reproduce a skill over a period of time • Divided into short-term motor memory (STMM) and long-term memory (LTMM)

  4. Holds all incoming information If not attended to it is lost  0.5 s Rehearsed information is passed to STM sensory information store

  5. 90% of information is lost  10 s Only rehearsed information is retained Has a limited capacity of 7±2 bits of information in adults (Miller, 1953) We overcome limitations to some extent by chunking – grouping things together e.g. we remember telephone numbers by chunking them into sets of 3 or 4 numbers Each set or chunk becomes one bit of information labelling – we give groups of things names or labels short-term memory

  6. Forgetting occurs due to: failing to rehearse overloading giving too much information interpolated activity activity between presentation of information and recall Forgetting in short-term memory

  7. Forgetting in short-term motor memory • Failure to rehearse • Length of retention interval • i.e. time between first and second performances of the movement • the greater the retention interval the greater the amount of forgetting • after about 80 s there is almost complete forgetting • Interpolated activity • When an old movement negatively affects performance of a new movement we call it proactive inhibition • When a new movement negatively affects performance of an old movement we call it retroactive inhibition • Retroactive inhibition does not occur if the old skill is well-learned

  8. Remembering in short-term motor memory • Rehearsal is vital • We remember location better than distance • Interpolated activity can aid retention • When an old movement positively affects performance of a new movement we call it proactive facilitation • When a new movement positively affects performance of an old movement we call it retroactive facilitation

  9. Long-term memory • Rehearsed information from STM is passed to LTM • Stages in memory formation in LTM • Encoding • Two substages, acquisition - registering and sensory analysis of information • consolidation - creation of a stronger representation • Storage • The creation and maintenance of a permanent record • Retrieval • Using the stored information to repeat a movement or recall facts • LTM has no capacity limitations

  10. Forgetting in long-term memory • Some argue that we do not forget • There may be some temporary difficulty with recall • Decay theory • Failure to practise leads to loss of memory trace • ‘use it or lose it’ • Craik and Lockhart’s (1972) levels of processing model • Consolidation and storage are aided by the depth at which the learner understands the information

  11. Forgetting and remembering in long-term motor memory • LTMM has no capacity limitations • Decay theory is well supported • Levels of processing model is well supported • Nature of the task is a factor • Continuous skills are better retained than discrete and serial • This is probably due to the repetitious nature of continuous skills, i. e., inherently more practice • Some evidence to show that serial skills are remembered better than discrete • Patterning phenomenon affects forgetting in LTMM • weforget the timing of a movement before the sequencing and spatial organization • Overlearning phenomenon affects retention in LTMM • Even when we have learned a skill, we need to go on practising it

  12. Declarative long-term memory • Also known as explicit memory • It is consciouslyencoded and recalled • It is subdivided into episodic and semantic memory • Episodic memory contains personal experiences • Semantic memory refers to knowledge or facts about things like how to multiply or divide, the rules of grammar and how to perform specific skills

  13. Non-declarative long-term memory • Also known as implicit memory • It holds subconsciouslyor implicitly learned information • It is sub-divided into four domains • Classical conditioning • Non-associative learning • The perceptual representation system (PRS) • Identifies and responds to situations of which it has a great deal of experience • It is responsible for quick responses to situations and quick decision making • Procedural memory • Memory for a vast amount of subconsciously acquired information both cognitive and motor

  14. Regional brain functions and memory • The brain regions initially encoding information will depend on the type of information, visual, auditory, verbal, motor or emotional • The right hemisphere is more involved in encoding spatial information and the left verbal or verbalizableinformation • There is a great deal of bilateral encoding • For declarative information, consolidation appears to be primarily undertaken by the hippocampus and, to a lesser extent, the thalamus • Once information has been encoded, it is stored throughout the neocortex, which consists of the outer layers of the cerebral hemispheres • The position of any specific memory will involve the regions that originally encoded the information and regions associated with these areas • Formation of memories comes about by the strengthening, over time, of synaptic (the region between two neurons, across which neurotransmitters pass) connections between neurons - this is called long-term potentiation (LTP) • Increased neurotransmitter synthesis and release at the synapse, synaptic pruning (the removal of synaptic connections between neurons which are not used) and neurogenesis (formation of new synaptic connections) form a process called neural plasticity or neuroplasticity

  15. Hippocampus plays a major role in the consolidation of declarative memory HYPOTHALAMUS HIPPOCAMPUS AMYGDALA RETICULAR ACTIVATING SYSTEM

  16. Development and memory • The cellular changes resulting in facilitation of synaptic connections is on-going throughout life but is particularly prominent in childhood • the child’s brain is well-endowed with nerve growth factors or neurotrophins, which are proteins that aid neurogenesis and neuroprotection • In STM, we see • instinctive chunking at about 7 years of age • adult-type rehearsal at around 9 years • According to Pascual-Leone (1970) the child’s functional mental capacity increases steadily up to 14 years • Neurogenesis continues even into old age but • only if the individual is active physically and/or mentally

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