Lecture 1 Flashcards
What is patient HM (Henry Molaison) famous for?
The treatment of his temporal lobe epilepsy.
What is temporal lobe epilepsy?
Recurrent, unprovoked seizures originating from the medial or lateral temporal lobes.
What are the two types of partial seizures and what are the differences between them?
Simple partial seizures: no loss of consciousness
Complex partial seizures: usually a specific motor sequence of events, with an eventual loss of consciousness.
What is hippocampal sclerosis?
Neuronal loss and gliosis (excess growth of glial cells after neuronal cell loss in a region).
How do you reduce seizures from hippocampal sclerosis?
The most effective method is by surgical removal of the lesioned hippocampus but that is usually a last resort, with medications being used first.
What are main tissues in the medial temporal lobes?
Cingulate gyrus, parahippocampal gyrus, entorhinal cortex, perirhinal cortex, hippocampal system.
What surgery did HM undergo?
Bilateral resection of extensive amounts of the medial temporal tissues, including the amygdala, most of the hippocampi and part of the hippocampal gyrus.
Distinguish between the two types of amnesias.
Retrograde amnesia: loss of memories from before injury.
Anterograde amnesia: unable to learn, retain and recall new memories; impairment of memories after injury.
Distinguish between the two types of memories.
Procedural memory: the “how”; unconscious
Declarative memory: the “what”; conscious
What type of memory impairment did HM have?
Declarative memory impairment.
What does HM’s memory impairment tell us about the medial temporal lobes and memory?
The MTLs are important for anterograde declarative memory procedures.
Is memory function localised? If not, which areas are involved?
No, it is not. It involves the unimodal and polymodal areas of processing, including the frontal, temporal and parietal lobes. But, the temporal lobes are the engine of memory.
Describe the functional asymmetry of the medial temporal lobes.
Left MTL lesions: verbal memory impairment.
Right MTL lesions: non-verbal/visual memory impairment.
What are the components of the hippocampal formation?
Dentate gyrus + CA1-CA3 (hippocampus proper) + Subiculum
Describe the information pathway in memory function.
Information is generated in the sensory systems and sent to the hippocampal formation for long term storage.
