G07 --> Memory Flashcards
(49 cards)
What is declarative memory?
Declarative –> conscious memory for facts, places and events
involve hippocampal formation, medial temporal lobe and diencephalon
What is non declarative memory (procedural memory) ?
Non-Declarative –> subconscious memory for skills, habits, emotional responses and some reflexes
involves the striatum, cerebellum and amygdala
Describe short term memory
New sensory information is processed into intermediate memory for several seconds then into short term
Describe long term memory
this information, depending on the perceived importance, may be consolidated into long term memory
There are two forms of long term memory, what is the first form?
Explicit declarative memory –> facts and events
happens in the medial temporal lobe
what is the second form of long term memory?
Implicit non declarative memory
(i) Priming –>one stimulus influences a response to another stimulus (neocortex)
(ii) Procedural Skills and Habits (striatum)
(iii) Associative learning classical and operational conditioning – >emotional responses (amygdala) and skeletal muskulature (cerebellum)
(iv) Non-associative learning: habituation and sensitization (reflex pathways)
What is working memory?
remembering numbers
What is amnesia?
Trauma to the brain may cause loss of memories
what are the two different types of amnesias?
- Retrograde –> loss of memory of past events before trauma
- Anterograde –> inability to form new memories following trauma and remember only the past
what is transient global amnesia?
Occurs typically in older men, recent events and information can only remembered for a few minutes. Normally all other functions are NOT impaired. Possible causes; TIA, basilar artery migraine, physical or psychic stress.
what is dissociative amnesia?
psychological reaction (witness of a severe accident or crime)
what is an Engram?
A theory that states how memory is stored as a biophysical/biochemical change in the brain
B. Neural network or fragment of memory in a cluster of neurons connected together
Where is the engram located?
distributed in the neocortex grouped into association areas, which receive input from the primary visual, auditory, and somatosensory cortexes
Where does the sensory information get sent upon entering the neocortex?
the association areas then send new sensory information to medial temporal lobes in the hippocampal formation which then relays it right back to the association area to consolidate into memory.
association areas are considered with what types of memories?
facts, events, places, language or emotions, past events, and ppl or working memory (note the engram pathway is drawn out and is a great guide for further understanding)
Clinical Cases Reveal Engram Locations: First clinical case–> removal of amygdala, uncus and most of hippocampus to treat epilepsy. resulted in what?
(i) retained IQ, language, long term memory, and ability learn new skills (procedural memory)
(ii) lost ability to make new memories (immediate/short –> long term impairment)
Second clinical case –> lesion to thalamus, medial temporal lobe and mammillary body from fencing sword up the nose. resulted in what?
(i) suffered anterograde amnesia
(ii) Retained his IQ, language, procedural skill learning and 2 years worth of long term memory
Third clinical case –> Stroke/TIA resulting in lesions to the hippocampus suffering marked loss of CA1 neruons. resulted in what?
(i) suffered from anterograde amnesia and unable to form new declarative memories
(ii) IQ, memories, and cognitive ability remained intact
The hippocampus facilitates storage of what?
storage from short term memory into long term memory
Where is the hippocampus located?
located in the hippocampal formation consisting of the dentate gyrus, fields CA1-CA3, the subiculum (parahippocampal gyrus) and of course, the hippocampus.
What is the general pathway for generation of declarative memory?
Cortical association areas –> Entorhinal Cortical Areas –> Dentate Gyrus –> CA3 –> CA1 –> Subiculum (generates back to the entorhinal cortical areas)
(note CA3 and CA1 are the hippocampus and Subiculum is the parahippocampual gyrus)
Passive of information through the declarative pathway look induces what?
induces synaptic plasticity (changing the physiological or morphological state of cells) at synapses on cells of the dentate gyrus, hippocampus and subiculum
what is long term potentiation (LTP)
When CA1 is excited by CA3 impulse trains at high frequencies (100/s), the excitatory synapse undergoes a long lasting increase in synaptic efficiency called long term potentiation (LTP)
Where does this potentiation take place?
on glutamatergic synapses on dendritic spines in the CA1 neuron
