memory systems Flashcards
1
Q
What is learning? How is memory defined?
A
-Learning is the process of acquiring new knowledge or skills.
-Memory is defined as the retention of learned information.
2
Q
Are learning and memory processed by the same neural hardware?
A
No, learning and memory may involve different neural structures and mechanisms.
3
Q
What is the distinction between declarative memory and nondeclarative memory?
A
Declarative (implicit) memory involves remembering facts and events, while nondeclarative (explicit) memory encompasses skills, habits, and behaviors.
4
Q
What is the distinction between episodic and semantic memory within declarative memory?
A
Episodic memory is for autobiographical life experiences, while semantic memory is for factual knowledge.
5
Q
What is procedural memory, and what does it involve?
A
Procedural memory involves remembering skills, habits, and behaviors, such as playing the piano, throwing a Frisbee, or tying shoelaces.
6
Q
How does nondeclarative memory differ from declarative memory in terms of conscious recollection?
A
Declarative memories are accessed consciously for recollection, while nondeclarative memories operate smoothly without conscious effort.
7
Q
What is one key difference between forming declarative and nondeclarative memories?
A
Declarative memories are relatively easy to form but can be easily forgotten, while nondeclarative memories require repetition and practice and are less likely to be forgotten.
8
Q
What is nonassociative learning?
A
Nonassociative learning is a type of learning that involves a change in behavioral response over time in response to a single type of stimulus. It includes two main types: habituation and sensitization.
9
Q
What is habituation?
A
Habituation is a form of nonassociative learning where an individual learns to ignore a stimulus that lacks meaning, resulting in a decreased response to that stimulus over time.
10
Q
What is sensitization in nonassociative learning?
A
Sensitization is another type of nonassociative learning where a strong sensory stimulus intensifies an individual’s response to all stimuli, even those that previously evoked little or no reaction
11
Q
What is associative learning, and how does it differ from nonassociative learning?
A
Associative learning involves behavior changes through the formation of associations between events. This is in contrast to nonassociative learning, where behavior changes in response to a single stimulus.
12
Q
What are the two types of associative learning typically distinguished?
A
The two types of associative learning are classical conditioning and instrumental conditioning.
13
Q
Describe classical conditioning and provide an example.
A
Classical conditioning involves associating a stimulus (conditional stimulus, CS) that doesn’t typically evoke a specific response with another stimulus (unconditional stimulus, US) that does evoke that response. For example, Pavlov’s dog associated the sound of a bell (CS) with the presentation of meat (US), resulting in salivation (CR).
14
Q
Explain instrumental conditioning and provide an example.
A
Instrumental conditioning involves learning to associate a specific behavior with a meaningful consequence, typically a reward. For instance, a hungry rat learns that pressing a lever leads to a food reward, and it continues to press the lever until it’s no longer hungry.
15
Q
How do the neural circuits involved in instrumental conditioning differ from those in classical conditioning?
A
The neural circuits in instrumental conditioning are more complex because motivation plays a significant role, and they involve predicting specific consequences of behavior, whereas classical conditioning focuses on stimulus associations.
16
Q
What is the property common to short-term memories, and how are they different from long-term memories?
A
Short-term memories are temporary and vulnerable to disruption. They can be erased by factors like head trauma or electroconvulsive therapy (ECT), unlike long-term memories, which are more permanent.
17
Q
What is working memory, and how is it different from short-term memory?
A
Working memory is a form of temporary storage that lasts for seconds, has limited capacity, and requires rehearsal. It is often described as information held “in mind” and is distinct from short-term memory due to its limited capacity and need for repetition.
18
Q
How is working memory commonly measured, and what is the typical digit span for most people?
A
Working memory is often measured by a person’s digit span, which is the maximum number of randomly chosen numbers they can repeat back after hearing a list read. The normal digit span is seven plus or minus two.
19
Q
what are the types of declarative memory
A
-working memory
-short term memory
-long term memory
20
Q
what is memory consolidation?
A
process of converting short- to long-term memories
21
Q
What are the two different types of memory loss that can occur following brain trauma?
A
Retrograde amnesia and anterograde amnesia
22
Q
What is retrograde amnesia characterized by? How might retrograde amnesia manifest in less severe cases?
A
-Retrograde amnesia is characterized by memory loss for events prior to the trauma.
-In less severe cases of retrograde amnesia, events of the months or years preceding the trauma are forgotten, but memory is increasingly strong for older memories.
23
Q
What is anterograde amnesia?
A
Anterograde amnesia is an inability to form new memories following brain trauma.
24
Q
What is transient global amnesia, and how long does it typically last?
A
Transient global amnesia is a sudden onset of anterograde amnesia that lasts for only a period of minutes to days, often accompanied by retrograde amnesia for recent events preceding the attack.
25
What might be implicated as a cause of transient global amnesia? What are some other factors that have been linked to transient global amnesia?
-Brief cerebral ischemia, in which the blood supply to the brain is temporarily reduced, or head trauma from accidents or blows could be implicated as causes of transient global amnesia.
-Seizures, physical stress, drugs, cold showers, and even sex have been linked to transient global amnesia, presumably because they can affect cerebral blood flow.
26
What is the potential consequence of transient global amnesia?
Transient global amnesia may be a consequence of temporary blood deprivation to brain structures essential for learning and memory.
27
What is the function of working memory?
Working memory holds sensory information for immediate behavioral needs, allowing us to remember and use information temporarily.
28
How does working memory differ from long-term memory?
Working memory has a limited capacity and holds information temporarily, while long-term memory stores information for an extended period.
29
What are some factors that influence the capacity of working memory?
Factors influencing working memory capacity include the length and complexity of information, the ability to chunk information into meaningful groups, and the behavioral significance of the information.
30
How is information retained in working memory long enough to be useful?
Research suggests that working memory is a capability of neocortex found in various brain locations, indicating that different regions contribute to retaining information in working memory.
31
What are some characteristics often associated with the prefrontal cortex in humans?
Characteristics like self-awareness, complex planning, and problem-solving.
32
What does the delayed-response task in monkeys suggest about the prefrontal cortex's role?
It suggests that the prefrontal cortex is involved in retaining information in working memory.
33
How did Phineas Gage's case illustrate the role of the prefrontal cortex?
Phineas Gage had difficulty planning and organizing behaviors due to severe frontal lobe damage.
34
What is the Wisconsin card-sorting test, and how does it relate to prefrontal cortical damage?
t's a test involving sorting cards based on changing categories. People with prefrontal lesions struggle when the sorting category changes, indicating a working memory deficit.
35
What is a common deficit seen in individuals with prefrontal lesions in various tasks?
They have difficulty learning from recent experiences, which suggests a working memory deficit
36
What response patterns do prefrontal cortex neurons exhibit during a delayed-response task?
Some neurons respond to visual stimulation, while others show increased activity during the delay period, potentially related to working memory retention.
37
Describe the identity task in a working memory experiment.
In the identity task, subjects are shown three face photographs in succession, memorize each face, and later indicate whether a new face matches one of the memorized faces.
38
Describe the location task in a working memory experiment
In the location task, subjects memorize the locations of three faces presented in succession, and later determine if a new face occupies the same location as one of the memorized locations.
39
What is the delay interval in a working memory experiment?
The delay interval is the time between memorization and the test phase when subjects must hold information in mind.
40
What did brain imaging experiments reveal about the areas involved in working memory for facial identity and spatial location?
Brain imaging experiments identified six areas in the frontal lobe with sustained activity during the delay period, suggesting their role in working memory. Three areas were more responsive to facial identity, one to spatial location, and two were equally active in both types of tasks.
41
What remains an unanswered question regarding working memory and brain areas?
An unanswered question is whether working memory for other types of information is held in the same or different brain areas.
42
describe the deficits linked to
orbitofrontal damage
-disinhibition
-altered personality
-lack of empathy (impaired ‘mind theory’)
-socially inappropriate
behaviour (impaired ‘mind theory’)
-reactive aggression
43
Deficits linked to medial prefrontal damage:
* decreased motivation
* apathy
* akinesia
* impaired detection of
mismatches or errors
44
Deficits linked to dorsolateral prefrontal cortex damage:
* reduced attentional control
* perseveration
* impaired “executive” functions
(working memory, sequencing, planning, creativity, reasoning)
45
What is the lateral intraparietal cortex (area LIP) thought to be involved in?
Area LIP is thought to be involved in guiding eye movements.
46
What happens in a delayed-saccade task involving area LIP in monkeys?
In a delayed-saccade task, the monkey fixates on a point on a computer screen, a target is briefly flashed at a peripheral location, and after a delay, the monkey makes a saccadic eye movement to the remembered location of the target.
47
What does the response of an LIP neuron during a delayed-saccade task indicate?
The LIP neuron begins firing shortly after the peripheral target is presented, continues firing throughout the delay period with no stimulus, and stops firing only after the saccadic eye movement begins.
48
How do other areas in the parietal and temporal cortex respond in working memory tasks?
Other areas in the parietal and temporal cortex also show working memory responses, and these responses are modality-specific, similar to the responses in area LIP.
49
How does the brain retain information for a longer time?
Declarative memory storage is involved in retaining information for a longer time.
50
What is an engram or memory trace?
An engram or memory trace refers to the location where a memory is stored in the brain.
51
What happened when rats with brain lesions were tested on the maze task? How did Lashley's research findings relate the size of brain lesions to learning and memory? According to Lashley's initial interpretation, did the location of the brain lesion within the cortex matter for memory? What impact did Karl Lashley's research have on the study of learning and memory?
-Rats with brain lesions, after initially learning the maze, made mistakes and went down blind alleys they had previously learned to avoid.
-Lashley found that the severity of deficits in learning and remembering correlated with the size of the brain lesions. Larger lesions resulted in poorer performance.
-According to Lashley's initial interpretation, the location of the brain lesion within the cortex did not matter for memory; all cortical areas contributed equally.
-Karl Lashley's research led to the consideration that memories might be distributed among the neurons of the cerebral cortex, even though his initial conclusions about equal contribution by all cortical areas were proven incorrect
52
Who was Donald Hebb and what did he propose in his book "The Organization of Behavior" in 1949?
Donald Hebb was a student of Lashley, and in his book "The Organization of Behavior," he proposed the concept of a "cell assembly," suggesting that the internal representation of an object consists of all the cortical cells activated by an external stimulus. He hypothesized that these cells were reciprocally interconnected and that the internal representation was held in working memory as long as activity reverberated through these connections.
53
How did Hebb suggest that consolidation of memory occurred in the brain? What was Hebb's important message regarding the engram?
-Hebb proposed that if activation of the cell assembly persisted long enough, consolidation would occur through a "growth process" that strengthened the reciprocal connections among neurons. This process meant that neurons that fired together would wire together.
-Hebb's message about the engram (the physical trace of memory) was twofold: (1) It could be widely distributed among the connections that link the cells of the assembly, and (2) it could involve the same neurons that are involved in sensation and perception. Destruction of only a fraction of the cells of the assembly would not be expected to eliminate the memory.
54
Where is the engram for a foreign language typically located in the brain?
The engram for a foreign language is typically found in the regions of the brain in the temporal and parietal lobes that normally process language. Lesions in these areas can disrupt memory of foreign words while leaving other memories, such as faces, intact. However, to reach the neocortex, declarative memories often must pass through structures in the medial temporal lobes.
55
What important function is attributed to the medial portion of the temporal lobe?
The medial portion of the temporal lobe contains the temporal neocortex, which is believed to be a site of long-term memory storage.
56
What structures are critical for the formation of declarative memories in the temporal lobe?
The key structures for the formation of declarative memories in the temporal lobe include the hippocampus, nearby cortical areas, and connecting pathways.
57
What are the three important cortical regions located ventral to the hippocampus in the temporal lobe?
The three important cortical regions are the entorhinal cortex (medial bank of the rhinal sulcus), the perirhinal cortex (lateral bank of the rhinal sulcus), and the parahippocampal cortex (lateral to the rhinal sulcus).
-entorhinal cortex and perirhinal cortex collectively as rhinal cortex
58
Where do inputs to the medial temporal lobe come from, and what type of information do they contain? Which visual cortex area projects to the medial temporal lobe?
-Inputs to the medial temporal lobe come from the association areas of the cerebral cortex and contain highly processed information from all sensory modalities, including complex representations, but go through parahippocampal and rhinal cortical areas first.
-The inferotemporal visual cortex (area IT) projects to the medial temporal lobe.
59
What is the major output pathway from the hippocampus, and where does it terminate?
The major output pathway from the hippocampus is the fornix, which loops around the thalamus before terminating in the hypothalamus.
60
What did Wilder Penfield's work involve? What were the sensations described by some of Penfield's patients during temporal lobe stimulation? What was an example of a patient's experience during temporal lobe stimulation?
-Electrically stimulating patients' brains as part of surgical treatment for severe epilepsy.
-They described sensations that sounded like hallucinations or recollections of past experiences
-One patient felt as though they were in the bathroom at school and later described a street corner in South Bend, Indiana, while looking at themselves at a younger age.
61
What is one interpretation of the sensations evoked by temporal lobe stimulation? How did sensations during temporal lobe stimulation differ from stimulation of other neocortical areas?
-The temporal lobe may play a special role in memory storage, but it's difficult to prove if the sensations are recalled memories.
-The consequences of temporal lobe stimulation and temporal lobe seizures can be qualitatively different from stimulation of other neocortical areas.
62
How were studies on the normal function of medial temporal neurons conducted?
complex sensations reported by minority
of patients, all with abnormal brains (epilepsy)
63
What types of objects did some neurons in the temporal lobe preferentially respond to?
Some neurons in the temporal lobe preferentially responded to categories of objects, including faces, household objects, and outdoor scenes.
64
What is the term used to describe neurons that respond to a variety of structurally or conceptually related visual images?
Neurons that respond to a variety of structurally or conceptually related visual images are described as "invariant."
65
What is the role of highly selective neurons in the hippocampus?
Highly selective neurons in the hippocampus may serve a role in the formation of new memories of people and things we already recognize.
66
Are these highly selective neurons essential for recognition?
It is unlikely that highly selective neurons in the hippocampus are essential for recognition because common objects and famous faces are recognized even after lesions to the hippocampus.
67
Who is Henry Molaison (H.M.)?
Henry Molaison, commonly known as H.M., was an individual who experienced seizures from a young age and underwent bilateral medial temporal lobe excision surgery at the age of 27 to alleviate those seizures.
68
What were the effects of H.M.'s temporal lobe surgery?
The surgery successfully stopped H.M.'s seizures. However, it resulted in profound anterograde amnesia, and he also experienced some degree of retrograde amnesia.
69
What is anterograde amnesia, and how did it affect H.M.?
Anterograde amnesia is the inability to form new long-term memories after a certain event. H.M. suffered from this condition, causing him to forget events shortly after they occurred, even if reminded.
70
Describe H.M.'s retrograde amnesia.
H.M. had limited memory of his childhood but little to no memory of events just before the surgery. The extent of his retrograde amnesia remains debated, with some suggesting it might extend back decades.
71
What was the state of H.M.'s working memory?
H.M.'s working memory was largely normal, but he could only retain information with constant rehearsal. Interruption would cause him to forget.
72
Despite his amnesia, what learning ability did H.M. retain?
H.M. could learn new tasks and procedural memories even though he had no recollection of the specific experiences. For example, he learned to draw by looking at his hand in a mirror.
73
What did H.M.'s case reveal about the role of the medial temporal lobe?
-H.M.'s case highlighted the importance of the medial temporal lobe in memory consolidation. It suggested that this region is not essential for memory retrieval or working memory.
-Removal of temporal lobes had no effect on perception, intelligence, personality
74
What distinction can be made between declarative and procedural memory based on H.M.'s abilities?
H.M.'s ability to retain declarative memories for some things (like famous faces and word meanings) indicated that not all memories rely on the medial temporal lobe. Procedural memory formation and retention may involve distinct brain structures.
75
What tasks are macaque monkeys trained to perform in memory experiments?
Macaque monkeys are trained to perform tasks like delayed match-to-sample and delayed non-match to sample (DNMS) tasks, where they judge whether a stimulus has been seen before.
76
What is recognition memory in the context of DNMS tasks?
Recognition memory, in DNMS tasks, involves the ability to judge whether a stimulus has been seen before, and normal monkeys are relatively good at this task, often correctly displacing the non-matching stimulus on about 90% of trials.
77
What does the performance of monkeys on the DNMS task reveal?
Monkeys' performance was close to normal if the delay between the sample stimulus and the two test stimuli was short (a few seconds). However, with longer delays, they made more errors choosing the non-matching stimulus, indicating a deficit in recognition memory.
78
What was the key finding related to perception and memory in the monkey experiments? What structures were damaged in the medial temporal lesions in monkeys?
-The monkeys' perception remained intact after the lesions, and they remembered the DNMS procedure. However, they had difficulty remembering the sample stimulus if the delay was too long.
-The lesions included the hippocampus, amygdala, and rhinal cortex, reflecting a large-scale damage to medial temporal structures.
79
What kind of amnesia did the monkeys with medial temporal lesions exhibit, and what were the characteristics?
Similar to H.M., the monkeys exhibited anterograde amnesia, involving declarative memory deficits, intact working memory, and severely impaired consolidation.
80
How did selective amygdala lesions and hippocampus lesions in humans differ in their effects on memory? (in terms of experiments done by Mortimer Mishkin and Larry Squire)
Selective amygdala lesions had no effect on recognition memory, while lesions of the hippocampus alone produced relatively mild amnesia.
81
What is the role of the perirhinal cortex in memory, and how does it relate to sensory information? (in terms of experiments done by Mortimer Mishkin and Larry Squire)
The perirhinal cortex may play a role in signaling familiarity in memory, regardless of sensory modality, reflecting the convergence of input from association cortex of multiple sensory systems.
82
What collective role do medial temporal structures, including the hippocampus and rhinal cortex, play in memory? What is the connection between medial temporal lobe lesions and anterograde amnesia? (in terms of experiments done by Mortimer Mishkin and Larry Squire)
-Medial temporal structures are critical for memory consolidation and may have an essential intermediate processing role in memory storage.
-Medial temporal lobe lesions, including structures like the hippocampus and rhinal cortex, are associated with anterograde amnesia, but interconnected areas in the brain can also produce amnesia.
83
How do rats with hippocampal lesions perform in the radial arm maze experiment compared to normal rats? How do rats with hippocampal lesions perform in the radial arm maze when food is placed only in certain arms? Why is it significant that rats with hippocampal lesions can avoid certain arms in the maze?
-Rats with hippocampal lesions go down the same arms more than once, unable to efficiently remember which arms they've already visited.
-They can learn to avoid the arms that never contain food but still struggle to efficiently get food from other arms without repeating some.
-It indicates that they can memorize certain aspects of the maze procedure, but they struggle with working memory for which arms they've already entered.
84
What is the hippocampus's role in memory? What type of memory does the hippocampus support in rodents? What is one of the specialized functions of the hippocampus?
-The hippocampus plays a critical role in binding sensory information for the purpose of memory consolidation.
-The hippocampus supports spatial memory, particularly for the location of objects of behavioral importance.
-Spatial memory, particularly related to the location of objects, might be one of the specialized functions of the hippocampus
-Involved in storage of memories for some
length of time
85
What is the Morris water maze?
The Morris water maze is a test of spatial memory in rats, designed by Richard Morris. It involves a rat placed in a pool of cloudy water with a hidden platform just below the surface.
86
How do normal rats perform in the Morris water maze? What happens in the Morris water maze test for rats with bilateral hippocampal damage?
-Normal rats quickly learn the spatial location of the hidden platform and swim directly to it in subsequent trials. They also adapt faster when the platform's location changes.
-Rats with bilateral hippocampal damage struggle to learn the game and remember the location of the platform, indicating the importance of the hippocampus in spatial memory.
87
What did John O'Keefe and his colleagues discover about hippocampal neurons?
John O'Keefe and his colleagues found that many neurons in the hippocampus selectively respond when a rat is in a particular location in its environment. These neurons are known as "place cells."
88
What is the term for the specific location in an environment that evokes the greatest response from a hippocampal neuron? What are place fields similar to?
-The specific location that evokes the greatest response from a hippocampal neuron is called the neuron's "place field"
-Receptive fields of neurons in sensory systems.
89
How can visual input affect the response of place cells?
Visual input can determine the response of place cells; for example, if a rat associates a certain location with a visual cue, place cells will respond based on that cue's presence.
90
What happens to place cell responses in the absence of visual cues?
Place cell responses remain location-specific even without visual cues, as long as the animal has explored the environment and developed a sense of location.
91
How do place fields behave when the environment is manipulated, such as stretching a box?
Place fields adjust to changes in the environment; for instance, they stretch in the same direction if the box is stretched.
92
What role might place cells play in memory and navigation tasks, like the radial arm maze?
Place cells could be involved in remembering locations already visited in tasks like the radial arm maze.
93
Are place cells present in the human brain? What did PET imaging studies show about the human hippocampus during virtual navigation?
-Whether place cells exist in the human brain is not confirmed, but PET imaging studies suggest that the human hippocampus is activated during tasks involving virtual or imagined navigation through environments.
-PET imaging studies revealed that the human hippocampus is activated when subjects engage in virtual navigation, suggesting its involvement in spatial processing.
94
what happens to brain activity during spatial navigation?
Increased activation in the right hippocampus and the left tail of the caudate.
95
Is there a pattern of asymmetry in brain activation during spatial navigation? What is the role of the hippocampus in human spatial navigation?
-Yes, there's often an asymmetry in the activation of the left and right hemispheres.
-The hippocampus is particularly active during spatial navigation tasks, similar to its role in rats.
96
How does hippocampal damage affect navigation skills?
Hippocampal damage can lead to difficulties in navigating smaller roads and fine-grained city topography.
97
What are grid cells, and where are they found in the brain?
Grid cells are neurons found in the entorhinal cortex that respond when an animal is at multiple locations forming a hexagonal grid.
98
Do humans also have grid cells?
Yes, recent experiments suggest that there may be grid cells in the human entorhinal cortex.
99
What did fMRI recordings in humans during navigation reveal about grid cells?
The recordings showed sinusoidal variation in the entorhinal cortex's fMRI signal, suggesting human grid cells exist.
100
How are place fields in the hippocampus formed, and what contributes to them?
Place fields may result from summation of inputs from grid cells, which continue to fire based on where the animal thinks it is.
101
What do place cells, grid cells, and head direction-sensitive neurons suggest about the hippocampus's specialization?
They suggest that the hippocampus is highly specialized for spatial navigation.
102
What theory suggests the hippocampus is specialized for creating a spatial map of the environment?
the cognitive map theory proposed by O'Keefe and Lynn Nadel suggests that the hippocampus is specialized for creating a spatial map of the environment.
103
How does the hippocampus integrate sensory input in tasks not entirely based on spatial memory?
The hippocampus can integrate sensory input in tasks not entirely based on spatial memory by forming associations between sensory stimuli, their spatial locations, and whether they are presented separately or together.
104
What is the role of the hippocampus in odor discrimination tasks, and how does it relate to spatial memory?
In odor discrimination tasks, the hippocampus plays a role in relating specific odors, their spatial locations, and whether they are presented separately or together. Hippocampal neurons become selectively responsive to certain pairs of odors and their spatial arrangements. Hippocampal lesions can produce deficits in this discrimination task.
105
How does the hippocampus link different experiences together in memory?
The hippocampus links different experiences together in memory by receiving a wide range of sensory inputs and integrating them. It may construct new memories by integrating sensory experiences associated with an event and connecting new sensory input with existing knowledge, effectively establishing memories for "what happened where."
106
What brain structures are involved in declarative memory formation?
The hippocampus, cortical areas around the hippocampus, the diencephalon, neocortex, and more.
107
What is the Standard Model of Memory Consolidation?
The Standard Model of Memory Consolidation is a model that describes the process of memory formation and storage. It involves initial processing of information in sensory-related neocortical areas, followed by synaptic consolidation and systems consolidation in the medial temporal lobe and neocortex.
108
What is Synaptic Consolidation?
Synaptic Consolidation is an early phase of memory consolidation in which changes in synaptic connections create a memory trace. It occurs before the more extended process of systems consolidation.
109
What is Systems Consolidation?
Systems Consolidation is a phase of memory consolidation where memory traces (engrams) are gradually transferred from the hippocampus to different neocortical areas, leading to permanent storage. After systems consolidation, the hippocampus is no longer needed for retrieval.
110
What is the Multiple Trace Model of Consolidation?
The Multiple Trace Model of Consolidation is an alternative model proposing that the hippocampus remains involved in memory storage, even for old memories. It suggests that each retrieval of an episodic memory forms a new memory trace involving both the hippocampus and neocortex, creating multiple traces for the same memory.
111
What is the Temporal Gradient in Retrograde Amnesia?
The Temporal Gradient in Retrograde Amnesia is a phenomenon where retrograde amnesia is more severe for recent memories compared to older memories. It is relevant to theories of memory consolidation.
112
What is an Engram?
An Engram is a theoretical concept representing a physical or biochemical change in the brain that is thought to correspond to a memory. It is believed to be the physical basis of stored memories.
113
What are Episodic Memories?
Episodic Memories are a type of long-term memory that involves the recollection of specific events, situations, and experiences in a person's life. They are often associated with personal experiences and can be vivid and detailed.
114
What is the Neocortex's role in memory?
The Neocortex plays a role in the storage of permanent memories, according to the Standard Model of Memory Consolidation. It is involved in higher-order brain functions, such as sensory perception, language, and conscious thought.
115
What claim did the 1968 by James Misanin, Ralph Miller, and Donald Lewis of Rutgers University report make about memories?
Memories can be altered or selectively erased even after consolidation.
116
What is reconsolidation in memory?
-Reconsolidation is the process by which a previously consolidated memory becomes labile and susceptible to change when reactivated, allowing for potential modification or alteration.
-In a rat experiment conducted by Misanin, Miller, and Lewis, rats:
-Rats were conditioned to fear a loud noise (conditional stimulus, CS) followed by a foot shock (unconditional stimulus, US).
-Retrograde amnesia for the conditioning occurred if ECS was administered immediately after conditioning.
-On the second day, some rats received the loud noise-foot shock combination, reactivating the fear memory.
After reactivation, ECS was applied.
-On the third day, the rats that had experienced the reactivation of memory exhibited significant disruption of their fear memory.
-This experiment suggests that memory reactivation can render memories labile and subject to reconsolidation.
Human reconsolidation experiments
–Recalling a memory makes it susceptible to
change
117
What are the two elements of the basal ganglia involved in procedural memory?
The caudate nucleus and the putamen, together called the striatum.
118
What role does the striatum play in the motor loop?
It sits at a key location in the motor loop, receiving input from frontal and parietal cortex and sending output to thalamic nuclei and cortical areas involved in movement.
119
What type of memory is critical for the procedural memory involved in forming behavioral habits?
Procedural memory.
120
How did studies with monkeys and rodents contribute to our understanding of declarative and procedural memory?
Studies with monkeys showed that lesions in the rhinal cortex of the medial temporal lobe disrupted the formation of new declarative memories. In rodents, lesions to the striatum had little effect on declarative memory tasks but impaired performance on tasks requiring procedural memory.
121
What is a "double dissociation" in the context of brain lesions and behavioral deficits?
A "double dissociation" refers to the situation where two different types of brain lesions lead to distinct behavioral deficits. In the case of the radial arm maze task, damage to the hippocampal system impaired performance on the standard maze task but not the light version, while a striatal lesion had the opposite effect.
122
What is the significance of the striatum's connectivity in relation to its role in procedural memory?
The striatum receives highly processed sensory information and sends out signals involved in motor responses. Its connectivity suggests that it plays a role in encoding and executing sequences of behaviors associated with procedural memory.
123
How does habit learning in monkeys relate to medial temporal lesions? What happens when the striatum is damaged in monkeys, and how does it affect memory?
-Habit learning in monkeys is relatively unaffected by medial temporal lesions.
-When the striatum is damaged in monkeys, there is no effect on the performance of the delayed non-match to sample task, but the ability to form habits is impaired.
124
How does Huntington's disease affect memory and habit learning, and what part of the brain does it target?
Huntington's disease affects memory and habit learning, particularly in tasks where a motor response is associated with a stimulus, and it primarily targets the striatum.
125
What role does the striatum play in habit learning and procedural memory in humans?
The striatum in humans may play a role in procedural memory, particularly in habit learning, as part of a system distinct from the medial temporal system used for declarative memory.
126
How did Parkinson's disease patients perform in a weather forecasting task compared to declarative memory questions, and what does this suggest about the role of the striatum in memory?
Parkinson's disease patients had difficulty learning the weather forecasting task but performed normally on declarative memory questions, suggesting that the striatum in humans may play a role in procedural memory distinct from the medial temporal system used for declarative memory.
127
