Memory
Memory - syllabus
Memory as storage, retention and retrieval of information.
All information entering the brain passes through sensory memory and enters short-term memory. Information is
then transferred to long-term memory (LTM) or discarded.
(i) Sensory memory — lasts a few seconds and retains all of the visual or auditory input.
(ii) Short-term memory (STM).
To include memory span, the serial position effect, maintaining items by rehearsal and loss of items by
displacement and decay. Improvement of STM by ‘chunking’.
(iii) Long-term memory (LTM).
The transfer of information from STM to LTM due to rehearsal, organisation and elaboration. Information is
encoded using shallow encoding or elaborative encoding. Retrieval is aided by the use of contextual cues.
(iv) Location of memory in the brain.
Episodic and semantic memory are stored in the cortex. Procedural memories (skills) are linked to the motor
cortex. Emotional memories involve links between the cortex and the limbic system. Spatial memory is located in
the limbic system.
Memory as storage, retention and retrieval of information.
Memory
Ability of the brain to store retain and retrieve information
Memory is selective
Receptors continuously transmit information to the brain but only a fraction of this is stored
Encoding
To enter memory, sensory stimuli must first be encoded
Encoding = Conversion of nerve impulses into a form that can be received and stored by the brain
Memory involves: encoding , storage and retrieval
All information entering the brain passes through sensory memory and enters short-term memory. Information is then
transferred to long-term memory (LTM) or discarded. (i) Sensory memory — lasts a few seconds and retains all of the visual
or auditory input.
(ii) Short-term memory (STM).
To include memory span, the serial position effect, maintaining items by rehearsal and loss of items by displacement and
decay. Improvement of STM by ‘chunking’.
Levels of memory
3 levels:
Sensory memory.
• Contains all visual and auditory stimuli perceived by the brain
• Short lived (0.5 seconds visual, 2 seconds auditory)
• Only a few stimuli selected for transfer to short term memory
Short term memory
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Limited capacity – about 7 items (called memory span)
Items held for a short time (about 30 seconds)
During this time retrieval is very accurate
Items then transferred to LTM or lost by displacement (being replaced by other items) or decay
Rehearsal (repetition) extends the time information is held in the STM
Chunking increases the number of items held (memory span)
Short-term memory (STM).
To include memory span, the serial position effect, maintaining items by rehearsal and loss of items by displacement
and decay. Improvement of STM by ‘chunking’.
Chunking
A chunk is a meaningful unit of information made up of several smaller units
Short term memory can only hold about 7 items
Chunking allows an increase in memory span by grouping several items into a single item
e.g. 8641 is four units
2016 (this year) is a single unit
Rehearsal
Repeating over and over (silently or aloud) a piece of information that you are trying to memorise
Helps to extend the time for which information is retained in the STM
Also helps to transfer information to the long term memory
Serial position effect
When presented with a series of items to remember, those at the start (primacy effect) and those at the end (recency
effect) are best remembered
Those at the start are remembered because there is time for them to have been rehearsed and for some to be encoded
and transferred to long term memory.
The last 7 or so items are remembered because they are still in the short term memory
Long-term memory (LTM).
The transfer of information from STM to LTM due to rehearsal, organisation and elaboration. Information is encoded using shallow encoding
or elaborative encoding. Retrieval is aided by the use of contextual cues.
Long term memory
Thought to be able to hold an unlimited amount of information
During encoding, items are organised into categories, e.g. personal facts, useful skills
They are then stored in the LTM
Transfer between STM and LTM
If an item is encoded while in the STM, this allows it to be stored in the LTM and later retrieved.
Transfer from STM to LTM is helped by
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Rehearsal
Organisation
Elaboration of meaning (elaborative encoding), e.g. making up a memorable story involving the facts to be
remembered
Rehearsal
Research shows that stopping and rehearsing information is more successful in transferring to LTM than reading
information continuously
Organisation
Information organised into logical categories is more easily transferred from STM to LTM
Retrieval is aided by the use of contextual cues.
Retrieval from the LTM
Retrieval is aided by contextual cues
Cue = reminder
Contextual = conditions or circumstances present when the information was encoded
The more categories under which the same information is stored, the more contextual cues and the
easier it is to retrieve
A memory whose encoding in the LTM was accompanied by unusually dramatic or emotional events
has powerful contextual cues that allow it to be retrieved easily
(iv) Location of memory in the brain.
Episodic and semantic memory are stored in the cortex.
Procedural memories (skills) are linked to the motor cortex.
Emotional memories involve links between the cortex and the
limbic system. Spatial memory is located in the limbic system.
Type of memory
Description
Location in the brain
episodic
Relate to experiences,
events and personal facts
Semantic
Relate to general
knowledge, non-personal
facts and concepts
Specific regions of the
cerebral cortex
(Believed that each
memory stored in the
cortex region that first
received the information)
Procedural
Relating to motor skills and Motor area of the cerebral
mental skills (e.g.
cortex
remembering how to read)
Emotional
Formed as a result of
positive or negative
responses to certain
stimuli
Involve links between the
cerebral cortex and limbic
system
Spatial
Information about a
person’s environment and
it’s spatial orientation
Limbic system
Type of memory
Description
Location in the brain
episodic
Relate to experiences,
events and personal facts
Semantic
Relate to general
knowledge, non-personal
facts and concepts
Specific regions of the
cerebral cortex
(Believed that each
memory stored in the
cortex region that first
received the information)
Procedural
Relating to motor skills and Motor area of the cerebral
mental skills (e.g.
cortex
remembering how to read)
Emotional
Formed as a result of
positive or negative
responses to certain
stimuli
Involve links between the
cerebral cortex and limbic
system
Spatial
Information about a
person’s environment and
it’s spatial orientation
Limbic system