Memory and Learning 1 Flashcards
Define learning
Process whereby new info is acquired by the nervous system and leads to a change in behaviour
Memory
The encoding, storage and retrieval of learned info
Name the two modes of memory
Declarative and Non-declarative(Procedural)
What is declarative memory?
memory available to consciousness and can be expressed by language i.e. can be declared
What is non-declarative memory
memory that involves skills and associations that are acquired and retrieved at an unconscious level
What are the types of non-declarative memory and where are they stored long-term?
Procedural-striatum
Motor skills-cerebellum
Emotional- amygdala
What are the types of declarative memory and where are they stored long-term?
Episodic (events)
Semantic (facts)
Both stored in the medial temporal lobe diencephalon
Name the three temporal types of modes of memory?
Immediate memory
Working memory
Long-term memory
What is immediate memory and what are its features?
The ability to hold ongoing experiences for a fraction of a second
Large capacity, each sensory modality has its own ‘memory register’
What is working memory and what are its features?
Ability to hold information in the mind for seconds to minutes while it is used to achieve a certain goal
Limited in duration and capacity
What is long-term memory and what are its features?
Memory that is retained for days/weeks/lifetime
Immediate or working memory can enter long term memory by conscious or unconscious rehersal
What is an engram?
The physical embodiment of memory in the neuronal machinery which depends on changes in synaptic connections and/or growth/reordering of these connections
What is memory storage called?
Consolidation. Sensory info can go be consolidated to long term memory via short term memory or directly
Forgetting
Unimportant info and unrehearsed memories deteriorate over time
Important not to retain everything, particularly immediate and working memories
Importance of forgetting illustrated by Patient ‘S’
individual that cannot erase info- has difficulties distinguishing important cognitive stimuli from trivial info
What is pathological forgetting called and how can it arise?
Amnesia
Arises from CNS injuries and disease
What are the two types of amnesia?
Retrograde- loss of memories for events preceding the trauma with greater loss towards the time of trauma
Anterograde- continued loss of a large percentage of memory function after the time of the trauma,
Case of H.M. anterograde amnesia
Bilateral medial temporal lobe resection
Amygdala, incus, hippocampal gyrus and anterior hippocampus removed to alleviate epilepsy
Resulted in profound loss of short term declarative memory function
Case of R.B. anterograde amnesia
Ischaemic episode during surgery
Failed on tests on ability to form new declarative memories
Bilateral lesion of hippocampus, particularly CA1 regions
What does declarative memory rely on?
Depends on the integrity of the hippocampus and its subcortical connections to the mammillary body and dorsal thalamus
What is the route of declarative memory consolidation?
Cortical association areas —-> Parahippocampal and rhinal cortical areas ——> Hippocamus ———> Thalamus, hypothalamus via the fornix
AND
———–> feeds back to cortical association areas
What structures are used to test spatial memory consolidation?
Morris water maze (invisible platform in pool)
and the radial arm maze (arms radiate from center area and some arms have food at end, others don’t)
What are the effects of lesions on radial arm and spatial maze learning?
Lesions specific to hippocampus - marked effects
Perirhinal lesions - less effect
Model for human episodic memory
Non-matching to sample, with or without delay
- train to visual stimulus, reward choice of non-matching pattern
- tests working memory and how long the memory is retained