Memory and Cognition Flashcards
What are the two different kinds of memory?
Declarative
Conscious
What are the three duration-controlled categories that memory can be split up into?
Immediate memory - few 100ms to 20secs
Short term memory - 1sec to a few hours
Long-term memory - 30mins to decades
Where is the majority of short term memory stored?
The cortex
What is required for information to remain in short-term memory?
Maintained excitation from reverberating circuits
What is retrograde amnesia?
Inability to remember immediate event up to 4 hours before the injury, but recall of event that happened a long time ago is unaffected
What is anterograde amnesia?
An inability to remember events occurring shortly after regaining consciousness, presumably because the cortical function is still disturbed - occurs in severe/complex injury
Describe ECT and outline its uses
ECT involves applying large amounts of electrical current to the head, under anaesthetic
Can be very successful in treating schizophrenia or depression
What is the relationship between noradrenaline and depression?
It is known that disruption of noradrenergic pathways through the limbic system are involved in causing clinical depression. increased NE causes elation, while decreased NE causes depression. This can be treated with drugs that increase the effects of NE, for example by blocking the re-uptake of NE e.g. tricyclic antidepressants
What is the relationship between exercise and depression?
It has now been shown to be beneficial in treating mild clinical depression and is associated with an increase in NE
What is another approach to treating clinical depression using serotonin pathways?
Blocking the serotonin (5HT) re-uptake. Prozac is an SSRI - serotonin specific reuptake inhibitor
What are the limitations of using Prozac?
Drugs that block NE re-uptake also block the serotonin. Both classes of drugs also take 4-6 weeks to have an anti-depressive effect
What are some side effects of Prozac?
It can cause extreme violence in some patients and they can act completely out of character
In what part of the cortex is the memory store?
The sensory and association areas
What is the name of the process by which short-term memory is converted to long-term memory?
Consolidation
How does consolidation occur?
It involves selective strengthening of synaptic connections by repeated use, similar to the method that occurs int he cerebellum during motor learning. It involves facilitation at synaptic sites, calcium, gene activation, protein synthesis and structural changes to the synapse and therefore it takes time. During the process the information is vulnerable to being wiped
What determines whether a memory is considered significant? Does the process only occur once?
The frontal cortex and its association with the reward/punishment areas of the limbic system asses the significance. If the information is deemed significant once, it will be assessed again several times before the consolidation is complete
How does information deemed significant continue to circulate so as not to be forgotten?
Once deemed significant, the frontal cortex ‘gates’ the PAPEZ circuit. Reverberating activity then continues around the circuit, the frontal cortex and the sensory and association areas until the consolidation process is complete
Where are visual components of memory laid down?
The visual cortex
Where are auditory components of memory laid down?
The auditory cortex
What does the laying down of different components of a memory in different areas of the brain mean for recall?
The memory must be re-assembled. Multiple associations can evoke the recall - olfactory stimuli are particularly powerful in evoking long-term memories
With which functional system is the auditory complex and auditory stimuli closely related to?
The limbic system
What is area of the limbic system particularly important in the consolidation process?
The hippocampus
What happens to the memory function of patients with bilateral hippocampal damage?
Immediate memory is retained as well as intact long-term memory, but they are unable to form new long-term memory. Their cerebellar memories intact, the effect is totally devastating
What is Korsakoff’s syndrome?
Most commonly occurs due to chronic alcoholism, the is vitamin B1 deficiency and malnutrition which leads to maxillary body damage. The ability to consolidate memory impaired
Describe Alzheimer’s disease
Severe loss of cholinergic neurons throughout the brain, including the hippocampus. It causes gross memory impairment, with progressive loss of cognitive function
Describe deja vu phenomenon
A feeling of familiarity with new events or surroundings is common in the dural phase of epilepsy
What makes up the Paper circuit?
Hippocampus
Anterior Thalamus
Mamillary body
Cingulate gyrus
