Chapter 7 (M32)

Module 32- Storing and Retrieving Memories

What is the capacity of long-term memory?

• Essentially limitless

What role do the frontal lobes play in semantic & episodic memory?

• Semantic memory: explicit memory of facts & general knowledge (one of our two conscious memory systems—other is episodic memory)

  • Ex: recalling a password & holding it in working memory — activate left frontal lobe

• Episodic memory: explicit memory of personally experienced events

  • Ex: calling up a visual party scene — activate right frontal lobe

The Hippocampus

• Hippocampus: a neural center located in the limbic system; helps process explicit (conscious) memories of facts and events for storage

• Considered the “save” button for memories

• Memories are NOT permanently stored in the hippocampus

  • This structure is where the brain registers & temporarily holds the elements of an episode (smell, feel, sound, location)

The Cerebellum

• Plays a key role in forming & storing the implicit memories created by classical conditioning

Basal Ganglia

• Involved in motor movement; facilitate formation of our procedural memories (implicit) for skills

• The basal ganglia receive input form the cortex but does not send info back to cortex for conscious awareness of procedural learning

The Amygdala

• Amygdala: two lima-bean-sized neural clusters in the limbic system; linked to emotion

• Our emotions trigger stress hormones that influence memory formation

• Stress provokes the amygdala to initiate a memory trace that boosts activity in the brain’s memory-forming areas

SIMPLY PUT: KEY MEMORY STRUCTURES IN THE BRAIN

• Frontal lobes & hippocampus —> explicit memory formation (declarative memory)

• Cerebellum & basal ganglia —> implicit memory formation (nondeclarative)

• Amygdala —> emotion-related memory formation

Infantile Amnesia

• As adults, our conscious memories of our first 4 years is largely blank — infantile amnesia

Retrieval Cues

• Best retrieval cues come from associations we form at the time we encode a memory — smells, tastes, sights can evoke our memory

Priming

• Priming: the activation, often unconsciously, of particular associations in long-term implicit memory

  • Ex: seeing the word “yellow” — asked to name a fruit, more likely to say “banana”

Context-dependent Memory

• Putting yourself back in the context where you earlier experienced something can prime your memory retrieval

  • Ex: when you visit childhood home —> old memories surface

State-dependent Memory

• What we learn in one physiological state (drunk or sober) may be more easily recalled when we are again in that state

Mood-congruent Memory

• Emotions that accompany good or bad events become retrieval cues

• Mood-congruent memory: the tendency to recall experiences that are consistent with one’s current good or bad emotional state

Serial Position Effect

• Serial position effect: our tendency to recall best the last (recency effect) and first (primary effect) items in a list