Testing of long term memory: Dr.Roopchand.PS Senior Resident Academic Department of Neurology TDMC, Alappuzha
Memory:• Ability of the brain to store and retrieve information. – Explicit memory: conscious, intentional recollection of an event or item of information. – Includes – immediate, short term and long term memories. – Implicit memory: Unconscious retention in memory, as evidenced by the effect of a previous experience or previously encountered information on current thoughts or actions. – Includes – motor memory.
Long term memory Procedural Declarative memories memories“Knowing how” “knowing that” Episodic memories Semantic memories ‘Personal ‘general knowledge’ recollection’
Contents of long term memory:• Procedural memory: – Memories for performance of action or skills – “knowing how”• Declarative memory: – Memories of facts, rules, concepts and events; includes semantic and episodic memory. – “knowing that”
• Semantic memory: – General knowledge, including facts, rules, concepts and propositions.• Episodic memories: – Personally experienced events and the contexts in which they occurred.
How to Remember things!!!• Maintenance rehearsal: rote repetition of material in order to maintain its availability in memory.• Elaborative rehearsal: association of new information with already stored knowledge and analysis of new information to make it memorable.
Anatomic correlate of long term memory:• Thought to reside in multiple cortical region. – Visual association cortex for visual memory. – Temporal cortex for auditory memory. – Left lateral temporal cortex : knowledge of word meaning.• fMRI studies support this concept.• Memory can be retrieved with out the hippocampal system from neo cortex.
Testing:• Personal information: – Where were you born? – School information – Vocation history – Family information
• Historic Facts: – Always consider patients education level. – Ask about common historic facts, if possible sequentially.
Registration vs Retrieval?• A clue is the clue to it.
Procedural memory testing:• Pursuit rotor task:• simple pure visual-motor tracking test that has consistent results within age groups.• measurement of procedural memory as well as demonstrates the participants fine-motor skills.• Amnesic participants show no impairment in this motor task when tested at later trials.• It does however seem to be affected by lack of sleep and drug use
• Serial reaction time task: – having participants retain and learn procedural skills that assess specific memory for procedural- motor skill. – Patiets with Alzheimers disease and amnesia demonstrate a long retention time which indicates that they are able to retain the skill and demonstrate effective performance of the task at a later point in time.
• Mirror tracing task: – looks at the integration of the senses . – it is a visual motor test where the participants learn a new motor skill involving hand-eye coordination. – Drawing the image is the work of your procedural memory. – once you figure out how to draw the image in the mirror you have little difficulty the second time. – Alzheimer’s disease are not able to recall the skills acquired in a mirror tracing task, but they acquire the procedural performance ability regardless