Week 5: Short-Term Memory

Question 1

How important is the MTL (medial temporal lobe) for the STM?

Answer 1

STM maintenance without MTL only possible if contents are actively focused on without distraction

Question 2

What is learning?

Answer 2

Process of acquiring new information through changes in synaptic connections

Question 3

What is memory?

Answer 3

The outcome of the learning process → cellular and circuitry changes in the nervous system

Question 4

What are the processing stages of learning ?

Answer 4

Encoding

Storage

Retrieval

Question 5

What is the Encoding stage?

Answer 5

=processing of incoming information and creation of memory traces (changes in synaptic strength)

Acquisition= only some of the stimuli are acquired in STM

Consolidation = stabilisation of memory over time (long-term)

Question 6

What is the Storage stage?

Answer 6

=retention of memory traces

Question 7

What is the Retrieval stage?

Answer 7

= accessing stored memory traces

Question 8

what are different kinds of memory loss?

Answer 8

Decay = information degrades and is lost over time

Interference = new information displaces old information

Question 9

What are the different types of short-term memory?

Answer 9

• sensory/iconic/echoic memory
• Short-term memory
• Working memory

Question 10

What is the sensory/iconic/echoic memory?

Answer 10

• Transient retention of sensory information
• high capacity
• Rapid decay (ms)
• Passive, no active maintenance
• Test: Afterimages ?

Question 11

What is the short-term memory?

Answer 11

• low capacity (~7 items)
• Rapid decay (several seconds)
• Fragile to Interference
• Active rehearsal possible, in principle „infinetly“
• Test: Digit Span Test

Question 12

What is the working memory?

Answer 12

• same as STM
• Maintenance and manipulation of information
• Shielding against interference
• Active transformation of contents
• Potential modular architecture
• Test: Mental rotation task

Question 13

What are the options for neural correlated of the STM?

Answer 13

Dorsolateral prefrontal cortex (dlPFC)

• Ablation = no retention after delayed response (having to chose food with cup underneath → bilateral lesion to PFC disrupts task
• Single neuron firing in oculomotor delayed response

Distributed

• sensory recruitment hypothesis: sensory information in sensory cortices, abstract information in PFC

Question 14

Spatial vs object memory

Answer 14

• spatial : dorsal stream
• Object: ventral stream
• Both end in PFC
• What and where cells equally divided between dorsolateral and ventrolateral PFC