Chapter 18: Learning and Memory

PSYCH 377

What was the primary reason for Henry Molaison's (H.M.) bilateral medial temporal lobe surgery?

To treat severe epilepsy.

Name three of the four brain structures/regions removed or partially removed during H.M.'s surgery.

Portions of the ventral medial temporal lobe, entorhinal cortex, amygdala, and part of the hippocampus.

What is the term for the inability to form most new memories, a condition H.M. experienced after his surgery?

Anterograde amnesia.

Despite his severe anterograde amnesia, what type of learning ability did H.M. retain?

He retained the ability to learn motor skills.

What is the term for the loss of some memories from before an event, which H.M. also experienced?

Retrograde amnesia.

The observation that memory for facts and memory for skills can be separated suggests that different _ support each type of memory.

brain systems

Term: Short-term memory

A memory system that stores information for a brief period, which can be extended by rehearsal but fades if not stored more permanently.

Term: Long-term memory

A more permanent storage system for information.

Which major category of long-term memory includes facts and events that we recall spontaneously and consciously?

Explicit memory.

Autobiographical memories for personal events are known as _ memories.

episodic

Memories for facts and general knowledge are known as _ memories.

semantic

Which category of long-term memory includes motor skills that can be performed automatically without full awareness?

Implicit memories.

Memories that include the affective properties of a stimulus, such as attraction, avoidance, or fear, are known as _ memories.

emotional

Amnesia caused by a brain injury where a person cannot form new memories is called _ amnesia.

anterograde

Amnesia caused by a brain injury where a person cannot access old memories from before the injury is called _ amnesia.

retrograde

In time-dependent retrograde amnesia, which memories are more likely to be lost?

More recent events are more likely to be lost than older memories.

What type of memory involves remembering things you intend to do in the future, like running an errand?

Prospective memory.

What type of memory is used for remembering past interactions, such as who you have already told a particular story to?

Destination memory.

Term: Childhood (or infantile) amnesia

The inability to remember events from the first 4 years of life and difficulty recalling things from the first decade.

What is one hypothesis for childhood amnesia related to hippocampal development?

The rapid proliferation of new hippocampal neurons early in life might disrupt stored memories.

What is a fugue state?

A sudden and usually transient loss of memory for one's personal history.

Damage to the memory systems of which brain lobe may cause a fugue state?

The medial temporal lobe.

What is the term for the awareness of a continuum from our past to our present to our future, allowing for 'mental time travel'?

Autonoetic awareness of time.

Damage to which two brain regions can cause a loss of autonoetic awareness?

The hippocampus and frontal lobes.

Semantic memory involves regions of the temporal and frontal lobes that are _ from the areas involved in episodic memory.

distinct

According to fMRI studies, a network of regions in which hemisphere is active during semantic memory tasks?

The left-hemisphere.

What network of structures supports explicit memory?

A network of temporal-lobe structures and parts of the ventral-stream pathway.

How do thalamic nuclei support explicit memory?

They serve to relay information from the prefrontal cortex to the temporal lobe.

The hippocampus includes two gyri: Ammon's horn and the _.

dentate gyrus

What type of cells are found in the four output layers (CA1-CA4) of Ammon's horn?

Pyramidal cells.

The dentate gyrus contains stellate granule cells which are unique because they undergo _ to produce new cells throughout life.

neurogenesis

Which cells of the hippocampus are the most sensitive to oxygen deprivation?

The CA1 cells.

The hippocampus connects to the posterior parietal and temporal cortex via the _ path.

perforant

The hippocampus connects to the thalamus and prefrontal cortex via the _.

fimbria fornix

According to case studies, where are older memories stored after initially being processed by the hippocampus?

In the adjacent cortex.

What is the typical outcome for memory if the hippocampus is damaged early in life?

Profound problems with episodic memory but fairly normal semantic memory.

The rhinal cortex of the temporal lobe includes which two specific cortices?

The perirhinal and entorhinal cortex.

What is the function of the rhinal cortex in relation to the hippocampus?

It is part of the pathway for information flowing into the hippocampus from the neocortex.

In lesion studies with monkeys, damage to which brain area impaired object recognition?

Lesions to the rhinal cortex.

In lesion studies with monkeys, what function was impaired by lesions to the hippocampus?

The use of context was impaired, but object recognition was not.

Damage to the right temporal cortex typically impairs what types of memory?

Face recognition, spatial position, and maze learning.

Damage to the left temporal lobe typically impairs what types of memory?

Memory for word lists, lists of consonants, and nonspatial associations.

What is prosopagnosia?

A specific form of amnesia for human faces, which can result from bilateral parietal and occipital lobe lesions.

Damage to the left prefrontal cortex is predicted to interfere with the _ of semantic and episodic memories.

encoding

Damage to the right prefrontal cortex is predicted to interfere with the _ of episodic memory.

retrieving

What is the key characteristic of implicit memory?

It includes learned skills and conditioned reactions that are nonconscious.

How did H.M.'s performance on the mirror drawing task demonstrate a dissociation between memory systems?

He showed standard improvement in the motor task (implicit memory) but had no conscious recollection of having performed the task before (impaired explicit memory).

Term: Priming

An experimental test of implicit memory where an initial stimulus presentation makes a subject more likely to respond later to the same or a similar stimulus.

How do patients with amnesia typically perform on priming tasks compared to control subjects?

They perform about as well as controls, even though they do not remember the training.

The proposed neural circuit for implicit memory suggests that multiple cortical regions and the substantia nigra project to the _.

basal ganglia

In the proposed implicit memory circuit, the basal ganglia projects to which part of the cortex?

The premotor cortex.

Brain-imaging studies during implicit memory tasks find increased activity in the basal ganglia, motor cortex, and the _.

cerebellum

Patients with Huntington disease, who have degeneration of the _, are impaired on classic tests of implicit memory like mirror drawing.

basal ganglia

Patients with which neurodegenerative disease, characterized by basal ganglia impairments, also show deficits of implicit memory?

Parkinson disease.

What brain structure is crucially involved in classical conditioning tasks, such as eyeblink conditioning?

The cerebellum.

Impairments in which neurotransmitter system are associated with Alzheimer disease?

The cholinergic system.

Simultaneous damage to which two ascending neurotransmitter systems can result in amnesia?

The cholinergic and serotonergic systems.

What is emotional memory?

Memory for the affective properties of a stimulus.

What brain structure is critically involved in fear conditioning and emotional memory?

The amygdala.

Damage to the amygdala impairs _ memory, but not implicit or explicit memory.

emotional

Short-term memory for object information uses the _ stream, which projects to the frontal lobe.

ventral

Short-term memory for motor information uses the _ stream, which projects to the frontal lobe.

dorsal

While damage to the medial temporal lobe impairs long-term memory, patients with this damage typically retain normal _ memory.

short-term

Damage to which brain region is often associated with short-term memory impairments?

The frontal lobe.

On neuropsychological tests, damage to the left frontal lobe causes the most significant impairment for _ material.

verbal

On neuropsychological tests, damage to the right frontal lobe causes the most significant impairment for _ material.

nonverbal

Term: Proactive interference

A phenomenon where earlier learned information interferes with the ability to recall later, similar information.

In interference tasks, patients with frontal-lobe damage show proactive interference but fail to show _ when the category of items changes.

release from interference

In monkey studies of short-term memory, neurons in which Brodmann area (BA) are active when monkeys remember the location of an object?

BA 8.

What is savant syndrome?

A condition where an individual can remember large amounts of information for long periods of time.

The case study of S., the reporter with savant syndrome, had a condition where stimuli were multisensory for him, known as _.

synesthesia

Term: Superior autobiographical memory

A condition where individuals show almost complete recall for personal events in their lives.

Theory: System consolidation theory

The hippocampus consolidates new memories, which are then stored elsewhere in the cortex.

Theory: Multiple-trace theory

Different aspects of a memory are stored in different parts of the cortex simultaneously.

Theory: Reconsolidation theory

As memories are recalled, they are changed or edited before being reconsolidated in their new form.

Theory: Trace transformation theory

Memories are initially encoded in the posterior hippocampus but move to the anterior hippocampus and then the medial prefrontal cortex, losing detail with each transformation.