Memory & Learning

Question 1

What is explicit memory?

Answer 1

Conscious memory of events and facts.

Question 2

What are the two types of explicit memory?

Answer 2

Episodic: Recall of personal experiences (autobiographical). Provides a sense of continuity or autonoetic awareness. Allows individuals to mentally travel into the past or future.

Semantic: All non-autobiographical knowledge about the world (facts, knowledge).

Question 3

What brain regions are associated with episodic memory?

Answer 3

○ Medial Temporal Lobe: Damage to this area, as seen in patient H.M., results in the loss of autobiographical memory.

○ Ventral Prefrontal Cortex: Damage to this area, along with damage to the fiber pathway that connects the temporal lobe to the ventral prefrontal cortex, impairs episodic experiences.

○ Uncinate Fasciculus: The fiber pathway connecting the temporal lobe to the ventral prefrontal cortex is important for episodic memory.

Question 4

What brain regions are associated with semantic memory?

Answer 4

○ Semantic memory does not depend on the medial temporal lobe or the ventral prefrontal lobe memory systems.

○ It depends on temporal and frontal lobe regions adjacent to the regions that are involved with episodic memory.

Question 5

What is the structure and function of the hippocampus in explicit memory?

Answer 5

Structure: Consists of two gyri:
■ Ammon’s horn: Contains pyramidal cells (CA1-CA4).
■ Dentate gyrus: Contains granule cells.

Connections:
■ Perforant pathway: Connects the hippocampus to the posterior temporal cortex.
■ Fimbria Fornix: Connects the hippocampus to the thalamus, prefrontal cortex, basal ganglia, and hypothalamus.

Question 6

What is the role of the temporal cortex in explicit memory?

Answer 6

○ Object Recognition: Depends on rhinal cortices.
○ Contextual Knowledge: Depends on the hippocampus.
○ Lateralization of Function:
■ Damage to the right temporal lobe = impaired memory of non-verbal material.
■ Damage to the left temporal lobe = impaired memory of verbal material.
○ Key Areas: Include the perirhinal cortex and entorhinal cortex, which are major input routes to the hippocampus.

Question 7

What other brain regions, besides the hippocampus and temporal cortex, are involved in explicit memory?

Answer 7

Parietal, Posterior Temporal, and Occipital Cortices: Associated with long-term memory

○ Frontal Cortex: Involved in autobiographical memory, but differs between encoding and retrieval
■ Left prefrontal: more involved in encoding memories than retrieving them
■ Right prefrontal: more engaged in retrieving memories than encoding them

Question 8

What do studies of hippocampal damage reveal about memory impairment?

Answer 8

Studies of hippocampal damage show the following:
1. Anterograde memory is more severely affected than retrograde memory.
2. Episodic memories are more severely affected than semantic memories.
3. Autobiographical memory is especially severely affected.
4. “Time travel” is diminished.

Question 9

What is implicit memory?

Answer 9

Consists of learned skills, conditioned reactions, and short-term events. It is unconscious and unintentional and therefore does not require manipulation by higher-level cortical processing.

Question 10

What are the different types of implicit memory?

Answer 10

○ Skills
○ Habits
○ Priming: A stimulus is used to sensitize the nervous system to a later presentation of the same or a similar stimulus.
○ Conditioning

Question 11

What brain regions are associated with implicit memory?

Answer 11

○ Basal Ganglia:
■ Receives projections from all regions of the cortex as well as from dopamine cells in the substantia nigra.
■ Sends projections through the globus pallidus and thalamus to the premotor cortex.

○ Motor Cortex: Shares connections with the
cerebellum, which contributes to implicit memory.

○ Cerebellum:
■ Involved with classical conditioning.
■ Mediates learning discrete, adaptive, behavioral responses.

Question 12

What is emotional memory?

Answer 12

Involves the affective properties of stimuli or events. Emotional memories may contain both implicit (unconscious) and explicit (conscious) aspects.

Question 13

What are some examples of emotional memory?

Answer 13

○ Attraction
○ Avoidance
○ Fear Conditioning: A noxious stimulus is paired with a neutral stimulus to elicit an emotional response.

Question 14

What brain regions are associated with emotional memory?

Answer 14

Amygdala: Involved in emotional memory and connects to the autonomic nervous system (ANS). Emotionally significant experiences activate both hormonal and brain systems. Future experiences can reactivate these circuits.

Question 15

What is the function of short-term memory and what brain region is associated with it?

Answer 15

○ Function: Used to hold sensory events, movements, and cognitive information for a brief period.
○ Relation to Sensory Processing: Related to both object-recognition (ventral) and motor/spatial (dorsal) streams of sensory processing.
○ Brain Regions:
■ Posterior-temporal region: Damage to this area results in the inability to repeat verbal stimuli.

Question 16

What neurotransmitter systems are involved in memory and what are their functions?

Answer 16

At least three neurotransmitter systems are involved in memory:
■ Cholinergic: Cells project from the basal forebrain to the frontal and temporal lobes. Loss of cholinergic cells is associated with memory loss in Alzheimer’s disease.
■ Serotonergic: Cells project from the midbrain to the limbic system and throughout the cortex.
■ Noradrenergic

○ Impact of Damage: Profound amnesia can be produced if the serotonergic cells and the cholinergic cells are damaged together

Question 17

What are the different types of amnesia?

Answer 17

○ Anterograde Amnesia: Unable to acquire new memories.
○ Retrograde Amnesia: Unable to recall memories from before the surgery.
○ Time-Dependent Retrograde Amnesia: The severity of injury will determine how far amnesia extends.

Question 18

What is childhood amnesia and what are some possible explanations for it?

Answer 18

○ Definition: Inability to remember events from infancy or early childhood.
○ Possible Reasons:
■ These personal memories are part of the episodic memory system which is not mature/ fully developed yet.
■ The brain may also delete them to make room for new memories.

Question 19

What are some rare forms of amnesia?

Answer 19

○ Fugue State: Adults have no knowledge of their former lives, but their skills and language remain intact. May be related to the temporary suppression of medial-temporal-lobe memory systems.
○ Selective Amnesia: People can be amnestic for nouns but not verbs or for faces but not animals.

Question 20

What are the causes and symptoms of transient global amnesia?

Answer 20

○ Possible Causes: Concussion or epilepsy.
○ Symptoms:
■ Involves the loss of old memories and an inability to form new ones.
■ Sudden loss of memory but short in length.

Question 21

How does Herpes Simplex Encephalitis affect memory?

Answer 21

○ Brain Region Affected: Can be accompanied by temporal-lobe damage.
○ Memory Impairment: May be unable to retrieve any information from part of life history. The insula, which accesses previously acquired memories, is damaged in herpes.

Question 22

How does Alzheimer’s Disease impact memory and what are the associated brain changes?

Answer 22

○ Progression of Memory Loss: Characterized by first anterograde amnesia followed by retrograde amnesia.
○ Brain Changes: First noticed in the medial temporal lobe and progress to other regions.

Question 23

What are the symptoms of Korsakoff’s Syndrome?

Answer 23

Consists of 6 major symptoms:
○ Anterograde & retrograde amnesia
○ Confabulation
○ Apathy
○ Lack of insight
○ Meager content in conversation
○ Onset and Progression: Symptoms appear suddenly and are progressive

Question 24

What is Savant Syndrome?

Answer 24

Someone with a developmental or intellectual disability has exceptional skills in another area. They often show difficulty understanding simple things.

Question 25

What are the characteristics and associated brain structures of individuals with superior autobiographical memory?

Answer 25

○ Characteristics: They display virtually complete recall for events in their lives, usually beginning around age 10.
○ Brain Structure: They show increased gray matter in the temporal and parietal lobes.

Question 26

What is the Multiple Trace Theory?

Answer 26

States that while the hippocampus consolidates the memory, the memories are stored elsewhere

Question 27

What brain regions are implicated in explicit and implicit memory?

Answer 27

○ Explicit Memory: Prefrontal cortex, medial temporal lobe, subcortical temporal lobe structures (hippocampus, rhinal cortex), and connecting pathways to the prefrontal cortex are implicated.
○ Implicit Memory: Pathways to the basal ganglia, motor cortex, and cerebellum are implicated.

Question 28

What brain regions mediate short-term memory?

Answer 28

○ Sensory regions of the neocortex mediate short-term memory:
■ The dorsal stream from the parietal and frontal cortex participates in short-term memory for locations.
■ The ventral stream from the sensory regions forward into the inferior temporal-dorsolateral prefrontal cortex mediates short-term memory for objects.

Question 29

What are some causes of memory impairment?

Answer 29

Memory impairments can result from brain injury or disease.

Question 30

What might exceptional memory be related to?

Answer 30

Some people have exceptionally good memories which may be related to better neural circuits.