Declarative Memory

Question 1

Declarative Memory

Answer 1

• For cued facts or past personal episodes, perceptual input first processed by cortical sensory areas, then to “Medial Temporal Lobe” (Hippocampus & associated structures), then to Mediodorsal Thalamus, then to Prefrontal Cortex (“Working Memory”) interconnected to other higher cortical areas

Question 2

Hippocampus

Answer 2

not just involved in spatial memory, but also in consolidating & retrieving declarative memories
e.g. Match-To-Sample task

Question 3

Match-To-Sample Task

Answer 3

Shown Sample stimulus, subject picks which of 2 Alternatives matches Sample

• Train rat on MTS until proficient; After rat learns task, lesion its Hippocampus
• Test w/novel stimuli, must apply “rule” (i.e. Pick alt that matches sample); Performance impaired

Question 4

Mediodorsal Thalamus

Answer 4

(like Hippo.) damage more likely to impact declarative than procedural memory

Question 5

Korsakoff’s Syndrome

Answer 5

Connections from Thalamus to Prefrontal Cortex appear damaged

Chronic alcoholism&raquo_space; vitamin B1 (Thiamine) deficiency, required for cells to metabolize glucose

• Anterograde amnesia (cannot form new memories) & Confabulation (make up stories based on current cues)

Question 6

H.M.

shows?

Answer 6

Famous epilepsy patient had Hippocampus, Amygdala & some Temporal Cortex removed

• Personality & IQ fairly intact, but suffered severe Anterograde Amnesia (+ some Retro for time near trauma)
• Couldn’t remember people he’d just met, page he’d just read; parents moved, couldn’t find his way home
• Could be taught a simple associative task (e.g. word + photo), so Working Memory still OK
• But could not recall it 15 min later - So Hippocampus may act to consolidate some types of memories
• W/repetitive training, learned new skills (e.g. “Tower of Hanoi” puzzle) but not recall having learned them
• So H.M. shows Long-Term Procedural (Skill) Memory but not Declarative (Fact) Memory

Question 7

Amygdala

Answer 7

also plays critical role in Consolidation of temporary associations into Long-Term Memories

• Emotion facilitates memory formation

Question 8

Block NMDA receptors in Basolateral Amygdala,

Answer 8

prevent learning; But after learning, blocker has no effect !

Question 9

Emotion facilitates memory formation

Answer 9

(Although extremes of emotion or stress can impair learning/memory)

• e.g. Arbitrary list of words easy to forget, except few “taboo” words that evoked emotional response

Question 10

memory for words

Answer 10

stored in inferior temporal