MEMORY DISORDER 1 Flashcards
(51 cards)
Whats the classification of amnesia?
Psychogenic
Organic
Whats the classification for memory distortions?
Disorder or recall
Disorders of recognition
Whats psychogenic amnesia?
Functional amnesia
Refers to an impairment of learning and memory out of all distortions to other cognitive functions
But can’t be related to indetifiable brain damage
Associated with impaired recall of previously acquired memories
- including autobiographical and semantic information
- in some cases it also affects the learning of new material
Whats dissociative amnesia?
- Psychiatric condition involving inability to recall important autobiographical memories.
- Occurs without known neurological or medical causes.
- May involve localized amnesia (e.g., specific time or stressful event).
- In severe cases, presents as global amnesia, affecting entire lifespan memory.
- Some may experience loss of identity and dissociative fugue (sudden travel away with amnesia).
In dissociative amnesia what’s teh decreased activation of?
Decreased activation of
- the ventromedical prefrontal cortex
- the bilateral posterior parietal cortices
Abnormal patterns were also identified during recognition and recollection tasks in both salience and central executive networks
Whats the key areas in the default mode network?
a group of connected brain regions that is active when your mind is at rest and not focused on the outside world
Posterior cingualte context - involved in memory and self-referential thought
- medial prefrontal cortex
- inferior parietal lobule
Whats organic amnesia?
Organic impairment of memory is referred as true amnesia and can affect different functions of memory
caused by physical damage or disease affecting the brain
Whats anterograde amnesia
Difficulty in learning new information
Whats retrograde amnesia?
Inability to remember events that happened before the brain damage occurred
Whats the casue of damage for anterograde amnesia?
Can be caused by damage to the temporal love where the hippocampus is located
Whats the time line for anterograde and retrograde amnesia?
Birth
Retrograde period
Date of brain injury
Anterograde period
Present day
Explain about the hippocampus?
It’s not a location for long-term memories, its not necessary for retrieval of long-term memories
It’s involved in the consolidation stage of memory
What did zola- Morgan and colleagues find out about anterograde amnesia: consolidation?
52 year old man - history of heart trouble - sustained a cardiac arrest
Period of anoxia - resulted in brain damage
Primary symptom - permeant anterograde amnesia
Analysing his brain 5 years later - CA1 field was primarily affected by - neurons completely degenerated
Whats Schaffer collaterals?
Axons from CA3 send information to CA1 pyramidal neurons
Whats hippocampus depdent anterograde amnesia?
Inability to form new long-term memories due to hippocampal damage; past memories remain mostly intact.
Whats metabolic disturbances?
casue glutamatergic to released glutamate at abnormally high levels
How does Ca²⁺ entry via NMDA receptors relate to memory and brain damage?
NMDA receptors allow Ca²⁺ into neurons to support memory formation (LTP), but too much causes excitotoxicity, leading to cell death and memory impairments.
Explain retrograde amnesia: retrieval?
Retrograde amnesia extends back for a limited period of time - hippocampal formation gradually transforms memories into permanent storage.
- before transfer is complete - the hippocampus is required for the retrieval of these memories
What did Hayley et al find?
People with retrograde amnesia vs healthy volunteers - recall of events more than 15 years old was as good as control participant’s.
Whats the retrieval of oldest memories activated less and less of where?
In the hippocampus
Opposite effect in the frontal cortex
Whats the transient global amnesia?
A sudden onset of anterograde amnesia - very little extent retrograde
Often accompanied by impairment in exacutive function and recognition - repetitive questioning
Can last up to 24 hrs
And is not linked to any other neurological impairment
Whats the feature of transient global amnesia?
Perseveration - the repetition of a particular response - word,phrase or gesture - regardless of the absence of cessation of a stimulus
Whats the risk factors in transient global amnesia?
- migraine
- focal ischemia
- venous flow abnormalities
- epileptic phenomena
- heart disease
- hyperlipidemia = high cholesterol
