Cognition Learning and Memory III

Question 1

What are the three temporal stages of memory?

Answer 1

• Short
• Intermediate
• Long

There is also iconic memory, which is the briefest memory and sensory impression that only lasts a few seconds.

Question 2

What are the three components of short term memory?

Answer 2

• Phonological loop
• Visuospatial sketch pad
• Episodic buffers

Question 3

How long do short term memories last?

Answer 3

Only about 30 seconds or throughout the duration of an activity. Retained with rehearsal.

Question 4

What is an intermediate-term memory?

Answer 4

It outlasts a short term memory but is not permanent (fades quickly without rehearsal). There is limited capacity for these memories (eg. the weather forecast for a few days, but not longer)

Question 5

Memories of different durations form by different neurochemical mechanisms. Drugs have been used to study memory formation.

Recall the timing of the effects of different amnestic agents.

Answer 5

• KCl blocks short term memory (5 min)
• Ouabain blocks intermediate-term memory (15 min)
• Anisomycin blocks long term memory (60 min) but not short term memory (by impairing protein synthesis)

Question 6

What are the two ways the experimenters determined that the formation of long-term memory requires protein synthesis?

Answer 6

Behavioural intervention: Training enriched experience by increasing the branching of dendrites and the number of synaptic contacts

Somatic intervention: The antibiotic anisomycin is very effective at inhibiting protein synthesis without toxic side effects (prevents long term storage in mice). The stronger the training, the longer the inhibition has to be.

Question 7

Protein synthesis involved in the formation of LTM appears to occur in two successive waves - the first about 1 hour after training. The second about 5 to 8 hours after training.

How did inhibitors of protein synthesis inhibit LTM formation during these two stages?

Answer 7

By preventing the structural changes in neurons that would normally encode the memory trace (engram)

Question 8

What is a classic demonstration of the fact that short term memory and long term memory rely on different processes to store information?

Answer 8

• The primacy effect (first stimulus encountered)
• The recency effect (last stimulus encountered)

Immediate tests: recency effect, no primacy effect

Short delay: Recency and primacy effect

Test after longer delay: Primacy effect but no recency effect

Question 9

A functional memory system incorporates the following three aspects:

Answer 9

Encoding to STM

Consolidation of STM/ITM to long term storage

Retrieval/recall of stored information

Question 10

How do the brain hemispheres differ in terms of encoding to short term memory of:

Pictures
Words

Answer 10

Recalling pictures

• Right prefrontal cortex
• Para-hippocampal cortex in both hemispheres

Recalling words

• Left prefrontal cortex
• Left para-hippocampal cortex

Question 11

Which neurotransmitters (3) can enhance memory formation in animal models?

Answer 11

• GABA
• ACh
• Opioids

Question 12

What is reconsolidation?

Answer 12

The return of a memory trace to stable long-term storage after it’s temporarily volatile during recall

• Reconsolidation can distort memories
• Leading questions can lead to remembering events that never happened