Module 37 - Memory

Question 1

What are the categories of human memory?

Answer 1

• Qualitative categories
  
  • Declarative vs non-declarative/procedural
• Temporal categories
  
  • Immediate vs working vs long-term

Question 2

What are the different qualitative categories of memory?

Answer 2

Declarative vs non-declarative/procedural

Question 3

What are the different temporal categories of memory?

Answer 3

Immediate vs working vs long-term

Question 4

What is the general concept of qualitative categories - “types” - of memory (the hierarchy)?

Answer 4

• Declarative = available to consciousness = you can say it out loud → often can be learned in a single exposure (one trial learning)
• Nondeclarative = generally not available to consciousness → usually requires many repetitions (gradual learning)

Question 5

What is the general concept of temporal categories - “stages” - of memory (the hierarchy)?

Answer 5

• Immediate memory
• Working memory
• Long-term memory

Question 6

What is the timeframe of each of the temporal categories - “stages” - of memory?

Answer 6

• Immediate memory
  
  • Fractions of a second-seconds
• Working memory
  
  • Seconds to minutes
• Long-term memory
  
  • Days-years

Question 7

What are the different anatomical structures that are involved at different times in the storage of explicit memories? (important question)

Answer 7

• Less than 1 second (“attention” or “registration”)
  
  • Brainstem - diencephalic activating systems, frontoparietal association networks, specific unimodal and heteromodal cortices
• Seconds to minutes (“working memory”)
  
  • Frontal association cortex; specific unimodal and heteromodal cortices
• Minutes to years (“consolidation”)
  
  • Medial temporal structures; medial diencephalic structures; specific unimodal and heteromodal cortices
• Years
  
  • Specific unimodal and heteromodal cortices

Question 8

True or false: you can forget things at any moment of the continuum of stages of memory.

Answer 8

True

Question 9

Which memory is implicit and which memory is explicit?

Answer 9

Declarative memory is explicit and nondeclarative memory is implicit

Question 10

What are some of the characteristics of declarative memory?

Answer 10

• Explicit memory
• Easily verbalized
• Conscious
• Often can be learned in a single exposure (one trial learning)

Question 11

Which structure(s) of the brain is responsible for forming new declarative memories? (important question)

Answer 11

Hippocampus and the diencephalon (which is composed of the thalamus and the hypothalamus)

Question 12

Which structure(s) of the brain is responsible for storing declarative memories?

Answer 12

Occurs in diffuse cortical areas

Question 13

What is the case of H.M. (1926-2008)

Answer 13

• He has a bilateral medial temporal lobe resection (1953)
• Removed hippocampus, amygdala, temporal cortex
• He then could not form new memories: problem with consolidation
• No problem with old memories → long term memory
• Some measures of memory were not affected
• WHAT WAS IMPACTED WAS THE TRANSFER FROM THE IMMEDIATE MEMORY TO LONG-TERM MEMORY = HIS WORKING MEMORY WAS IMPACTED

Question 14

What happens 2 years post-operation in the case of H.M. (1926 - 2008)

Answer 14

• Intelligence scores similar to pre-operation
• No deficits in perception, abstract thinking, or reasoning
• Could form non-declarative memories
• BUT he could not form DECLARATIVE memories

Question 15

How were we able to determine that H.M was able to form non-declarative memories?

Answer 15

• The number of errors to form the task of drawing between the lines in a mirror = # of errors decreased

Question 16

What was everyday life like for H.M?

Answer 16

• Obvious inability to recall events n his daily life
• Memory deficiency was “permanent”
• “Every day is alone… whatever enjoyment I’ve had and whatever sorrow I’ve had.” -H.M

Question 17

What is the difference between retrograde amnesia and anterograde amnesia? (important question)

Answer 17

• Retrograde amnesia (RA) is a loss of memory-access to events that occurred or information that was learned in the past. It is caused by an injury or the onset of a disease.
• Anterograde amnesia is a loss of the ability to create new memories after the event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact.

Question 18

There is another case called patient N.A. He was in a fencing foil accident and damaged his thalamus and mammillary bodies in the brain (without damage to other parts in the brain). What type of deficits did the patient have? What are the structures that this patient damaged known for?

Answer 18

• Similar amnesia to H.M. case
• The thalamus and mammillary bodies are particularly sensitive to alcoholism → they degenerate.
• Can present with anterograde and retrograde amnesia

Question 19

What is Korsakoff’s syndrome?

Answer 19

• Alcoholism, thiamine (B1) deficiency
• Thalamus and mammillary bodies degeneration
• Anterograde and retrograde amnesia

Question 20

What did these cases teach us? What are the important structures for declarative memory? (important question)

Answer 20

• Midline diencephalic structures
  
  • Left diencephalic lesions: verbal memory deficits
  • Right diencephalic lesions: visual-spatial memory deficits
• Medial temporal lobe structures (hippocampus)
  
  • Establishes new declarative memories (inability = anterograde amnesia)

Question 21

What happens with a left diencephalic lesion? (important question)

Answer 21

Verbal memory deficits

Question 22

What happens with a right diencephalic lesion? (important question)

Answer 22

Visual-spatial memory deficits

Question 23

What did the study with the taxi drivers in London demonstrate?

Answer 23

• The number of months spent as a taxi driver (months) correlated with the size of the hippocampus
• The time spent learning the roads of London = meant a larger hippocampus volume
• This tells us that the hippocampus has a very important role in establishing new declarative memories.

Question 24

What is retrograde amnesia is typically more indicative of what?

Answer 24

Retrograde amnesia (loss of events preceding injury) more indicative of generalized lesions associated with head trauma &/or degenerative disorders

Question 25

Anterograde amnesia is typically indicative of damage to which structures?

Answer 25

* Midline diencephalic structures * Medial temporal lobe structures (hippocampus)

Question 26

Immediately after a TBI injury, what can we expect to see in a patient?

Answer 26

* Immediately after the injury, when the patient cannot form any new memories and suffers from anterograde amnesia, typically associated with: * Restlessness * Increased agitation * Disruption of the sleep/wake cycle * But they also have preserved memories from long ago * Typically know who their family is * Typically know where they work * Etc. * But they also have a small retrograde amnesia period.

Question 27

What is the goal standard measurement for objective tests after a TBI?

Answer 27

* GOAT = The Galveston orientation and amnesia test * A clinically useful tool for monitoring post-traumatic amnesia

Question 28

What type of question does the GOAT assessment ask?

Answer 28

* Ask questions about long term memory * When were you born and what is your name * Ask questions about immediate memory * Where are you now and how did you get here * Ask questions surrounding the accident → the time around the injury to the head * When were you admitted to the hospital

Question 29

What is a normal score on the GOAT?

Answer 29

Normal = 76 - 100

Question 30

What is a borderline score on the GOAT?

Answer 30

Borderline = 66 - 75

Question 31

What is an impaired score on the GOAT?

Answer 31

Impaired \< 66

Question 32

True or false: The GOAT is used to determine when a patient is ready to move on from the acute care site to the rehab site.

Answer 32

* True, we want to use the GOAT to have a good idea if the patient is able to remember and retain new information. * Rehab center you will need to start remembering and retaining new info, therefore it would not be appropriate to transfer the patient when they are in a state of post-traumatic amnesia

Question 33

What type of scoring would a patient have on the GOAT in the post-traumatic amnesia phase after the TBI?

Answer 33

GOAT \< 75 but it will diminish over time

Question 34

What is the interpretation of the GOAT?

Answer 34

The duration of post-traumatic amnesia (PTA) is defined as the period following a coma in which the GOAT score is \< 75. PTA is considered to have ended if a score \> 75 (sign should be greater than) is achieved on three consecutive administrations (3 different days for example)

Question 35

What is the prognostics of the GOAT?

Answer 35

* Duration of PTA after a TBI provides one of the earliest and best predictors of long-term outcome * The longer someone remains in this PTA will have a worse prognosis, compared to someone who remains in this PTA state for a shorter period of time.

Question 36

Fill in the blanks !!! (important question)

Answer 36

IMAGE

Question 37

Which structures are necessary for forming new memories?

Answer 37

The hippocampus and the medial diencephalic structures

Question 38

Damage to either the hippocampus and the medial diencephalic structures causes what?

Answer 38

Anterograde amnesia

Question 39

We know how (kind of) new memories are formed, meaning that we know what brain structures are important for forming new memories. BUT, where are the long-term declarative memories stored?

Answer 39

* Storage occurs in the cortex * Storage site related to the modality in question (e.g. visual cortical areas appear to be involved in storing visual memories) * Degradation in long-term memory proportional the amount of cortex damaged (mass action principle) * If a lot of your cortex is damaged, you are probably going to lose a lot of memory.

Question 40

What is the mass action principle?

Answer 40

* Degradation in long-term memory proportional the amount of cortex damaged * If a lot of your cortex is damaged, you are probably going to lose a lot of memory.

Question 41

Where is the acquisition and storage of declarative information for short-term memory storage?

Answer 41

Hippocampus and related structures

Question 42

Where is the acquisition and storage of declarative information for long-term memory storage?

Answer 42

A variety of cortical sites: Wernicke’s area for the meanings of words, temporal cortex for the memories of objects and faces, etc.

Question 43

What happens when you aks a patient to recall one of the images you have shown to them on a screen after a series of pictures, for example, a chair?

Answer 43

* The same areas of the brain light up when you are perceiving an object as when you are recalling/ imagining it. * In this case, imagery is remembering = considered as memory * You can see that the blue spaces light up = the chair * This concludes a theory that memories are stored in the cortex or part of the cortex that is responsible for the modality * For example, if you remember how someone’s voice sounds like = it would be stored in the auditory cortex.

Question 44

What factors help with forming long term memories? (How do we remember things better?)

Answer 44

* Association is important for storage * The capacity of working memory depends upon meaning to the person and amount of associated information that has already been stored * For example, let’s say someone really likes pizza, they can tell you all the good pizza shops in Halifax. If you add a new pizza shop that opened, it will be easy to remember since you associate with the rest. * But if you compare it to someone who does not like pizza, the names of the pizza shops will be so random to the person that they won’t remember them → so if you add the name of the new pizza place, it is going to be difficult to remember * Motivation and interest also influence memory * Adult learning principles * For example, this neuroscience might be difficult to learn since you have not done much neuroscience but you are motivated to pass this class, therefore you will learn it * \*\*\*We know that a lot of storage happens by association * \*\*\*The normal human capacity for meaningless information ~ 7- 9 digits

Question 45

What is the normal human capacity for meaningless information?

Answer 45

~7 to 9 digits

Question 46

Why are we better at remembering an image of food when we are hungry?

Answer 46

Motivation → better at remembering things about food when we are hungry

Question 47

How do we retrieve long-term memories? We (kind of) know how we form and store memories, but how do we retrieve them later?

Answer 47

* Retrieving memories appears to involve frontal lobes * Damage to frontal lobes = difficulty with recall, sometimes accompanied by confabulation → (Confabulation is a symptom of various memory disorders in which made-up stories fill in any gaps in memory. German psychiatrist Karl Bonhoeffer coined the term “confabulation” in 1900. He used it to describe when a person gives false answers or answers that sound fantastical or made up.)

Question 48

What happens to damage to the frontal lobe in terms of memory?

Answer 48

Damage to frontal lobes = difficulty with recall, sometimes accompanied by confabulation → (Confabulation is a symptom of various memory disorders in which made-up stories fill in any gaps in memory. German psychiatrist Karl Bonhoeffer coined the term “confabulation” in 1900. He used it to describe when a person gives false answers or answers that sound fantastical or made up.)

Question 49

What is confabulation?

Answer 49

It is when people make stuff up to make up for the fact that they don’t remember → (Confabulation is a symptom of various memory disorders in which made-up stories fill in any gaps in memory. German psychiatrist Karl Bonhoeffer coined the term “confabulation” in 1900. He used it to describe when a person gives false answers or answers that sound fantastical or made up.)

Question 50

What are some of the characteristics of non-declarative?

Answer 50

* “Implicit” memory * Difficult to verbalize * More unconscious * Usually require many repetitions (gradual learning) * Example = learning how to play a sport

Question 51

Which structures in the brain are responsible for nondeclarative memory?

Answer 51

* Premotor cortex * Basal ganglia * Amygdala * Cerebellum

Question 52

What are the four different types of nondeclarative memory?

Answer 52

* Procedural motor learning * Classical conditioning * Priming * Operant conditioning

Question 53

What is procedural motor learning?

Answer 53

* Example → HM star diagram * Skiing * Shooting a basketball * Riding a bike * Dancing * Playing the guitar * It is motor learning → therefore all the brain structures that ADAM talked about for motor learning are also important for procedural motor learning.

Question 54

What is the basal ganglia’s involvement in procedural motor learning?

Answer 54

* We know that the Basal Ganglia is extremely important for motor learning and motor skill acquisition. * A study has been done → different doors and where a reward was behind one of the doors; patients with Parkinson’s disease that did not have their dopamine medication → did not do very well with this task = to notice that the reward was behind a specific door/ then when on medication patients did better and controls = not with PD = did great. * This just serves as a bit of support to know that dopamine and the basal ganglia re important for procedural motor learning.

Question 55

Where is the acquisition and storage of nondeclarative information for short-term memory storage?

Answer 55

Sites unknown but presumably widespread

Question 56

Where is the acquisition and storage of declarative information for long-term memory storage?

Answer 56

* Cerebellum * Basal ganglia * Premotor cortex * And other sites related to motor behavior

Question 57

What is classical conditioning?

Answer 57

* Learn to associated two sensory stimuli (classical conditioning) * Pavlov and his dogs E.g. food (unconditioned stimulus) → salivation (unconditioned response) * Present bell just before food, the animal learns association and begins salivating when the bell is sounded (now a conditioned response to a conditioned stimulus)

Question 58

What is priming?

Answer 58

* Priming is “change in the processing of a stimulus due to a previous encounter with the same or related stimulus… with or without conscious awareness of the original encounter” - P. p. 698 * Resistant to brain damage, aging, and dementia → meaning that these individuals still respond to priming quite well.

Question 59

Explain the study to show how priming works.

Answer 59

* Participants are shown “primed” list under false pretenses (for example, within a paragraph) * Later asked to complete word stem list (task 2) - contains stems of words and both primed and unprimed list. * In task 2, participants complete stems of primed words to form primed words themselves more often than chance would predict. * What this means is that because the individual had seen the primed words before, the patient was much quicker to fill in words like “element” or “technical” because these words where primed.

Question 60

What is operant conditioning/instrumental conditioning?

Answer 60

* Learn to associate a stimulus with a response * For example, when a certain behavior is followed by a reinforcing stimulus the likelihood of that behavior changes. * Positive reinforcement (reward) leads to increase in that behavior. * Negative reinforcement (punishment) leads to decrease in that behavior. * Basal Ganglia!

Question 61

What type(s) of nondeclarative learning are the basal ganglia important for?

Answer 61

Operant conditioning Procedural motor learning

Question 62

Why do we know that the basal ganglia, cerebellum, and pre-frontal cortex are important structures for memory storage?

Answer 62

Because damage to these structures interferes with the ability to learn new motor skills

Question 63

In general, where would visual information/memories be stored?

Answer 63

In the visual association cortices

Question 64

In general, where would auditory information/memories be stored?

Answer 64

Auditor association cortices

Question 65

True or false: Memories are not primarily stored within brain regions originally involved in processing each kind of information.

Answer 65

False = they are !!!

Question 66

Are declarative and non-declarative memories both primarily stored within brain regions originally involved in processing each kind of information?

Answer 66

YES, non-declarative memories are similar to declarative memories.

Question 67

We know that retrieving DECLARATIVE memories appears to involve the frontal lobes. BUT, what about NON-DECLARATIVE?

Answer 67

Likely very similar regions for RETRIEVING … (this is distinct for learning and storage)

Question 68

Is there an evolutionary pressure on neural connections for some “memory”? How do we know?

Answer 68

* Yes, some “memory” appears to come from evolutionary pressure on neural connections. * From birth (i.e. before they could have learned this association), baby birds are scared of shadows that look like predators, but not other shadows… proves that it is learned before they are born.

Question 69

Making a change in synaptic plasticity lasting more than a few hours requires ___________ and \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. These take at least several hours,i.e. Considerably longer than any short-term plasticity.

Answer 69

Making a change in synaptic plasticity last more than a few hours requires gene transcription and protein synthesis. These take at least several hours,i.e. Considerably longer than any short-term plasticity.

Question 70

True or false: As our memory moves into long term memory we likely need changes in gene transcriptions. There are likely structural changes.

Answer 70

TRUE

Question 71

What are the different memory cellular mechanisms involved at different times in memory storage?

Answer 71

* Seconds to minutes * The ongoing electrical activity of neurons * Changes in intracellular Ca2+ and other ions * Changes in second messenger systems * Minutes to hours * Protein phosphorylation and other covalent modifications \ * Expression of immediate early genes * Hours to years * Additional changes in gene transcription * Translation resulting in structural changes of proteins and neurons

Question 72

What are the memory cellular mechanisms involved in memory storage within seconds to minutes of the memory?

Answer 72

* The ongoing electrical activity of neurons * Changes in intracellular Ca2+ and other ions * Changes in second messenger systems

Question 73

What are the memory cellular mechanisms involved in memory storage within minutes to hours of the memory?

Answer 73

* Protein phosphorylation and other covalent modifications * Expression of immediate early genes

Question 74

What are the memory cellular mechanisms involved in memory storage within hours to years of the memory?

Answer 74

Additional changes in gene transcription Translation resulting in structural changes of proteins and neurons

Question 75

What are the different anatomical structures involved at different times in the storage of explicit memories?

Answer 75

* Less than 1 second (“attention” or “registration”) * Brainstem-diencephalic activating systems * Frontoparietal association networks * Specific unimodal and heteromodal cortices * Seconds to minutes (“working memory”) * Frontal association cortex * Specific unimodal and heteromodal cortices * The ongoing electrical activity of neurons * Minutes to years (“consolidation”) * Medial temporal structures * Medial diencephalic structures * Specific unimodal and heteromodal cortices * Years * Specific unimodal and heteromodal cortices

Question 76

What are the different anatomical structures involved at less than 1 second in the storage of explicit memories? (important question)

Answer 76

* Less than 1 second (“attention” or “registration”) * Brainstem-diencephalic activating systems * Frontoparietal association networks * Specific unimodal and heteromodal cortices

Question 77

What are the different anatomical structures involved at seconds to minutes in the storage of explicit memories? (important question)

Answer 77

* Seconds to minutes (“working memory”) * Frontal association cortex * Specific unimodal and heteromodal cortices * The ongoing electrical activity of neurons

Question 78

What are the different anatomical structures involved at minutes to years in the storage of explicit memories? (important question)

Answer 78

* Minutes to years (“consolidation”) * Medial temporal structures * Medial diencephalic structures * Specific unimodal and heteromodal cortices

Question 79

What are the different anatomical structures involved at years in the storage of explicit memories? (important question)

Answer 79

* Years * Specific unimodal and heteromodal cortices

Question 80

Can we observe physical changes associated with memory storage/performance?

Answer 80

* There is structural changes that occur with learning and memory * For example, the hippocampal volume (related to remembering spatial information) correlated with time as taxi driver (a job which depends on skill in this area) * Hippocampal = responsible for spatial information

Question 81

True or false: The hypothalamus is responsible for remembering spatial information.

Answer 81

FALSE → the hippocampus

Question 82

How is memory affected by brain damage?... gives examples of possible causes to create memory loss.

Answer 82

* Hemorrhages (little blood-brain bleeds)→ they can be multifocal (DAI = diffuse axonal injury) or unifocal (in one spot) = usually multifocal for memory loss. * Contusions (bruise to the brain) → anteromedial temporal lobes (because we know that it is where the hippocampus and diencephalon are located) * Concussions infarcts or ischemia * Global cerebral ischemia - memory often prominent * Top or basilar artery or PCA - medial temporal lobes, medial thalami * Hippocampus particularly vulnerable to anoxic injury * ACA aneurysm - damage to basal forebrain - memory loss as well as deficits seen with frontal lobe lesions.

Question 83

Name a degenerative disease that could cause memory loss.

Answer 83

Alzheimer’s - selective disease process to bilateral hippocampal, temporal, and basal forebrain structures.

Question 84

Name a few examples of multifocal lesions that could cause memory loss.

Answer 84

* Multiple sclerosis * Tumor * ICH → Intracerebral hemorrhage * CNS infection * Toxicity/metabolic encephalopathies * Vasculitis * Hydrocephalus * Etc.

Question 85

What is psychogenic amnesia?

Answer 85

* NO damage to temporal lobes * It is a potential cause for memory loss * It can cause symptoms like * Dissociation * Repression * Conversion * Malingering

Question 86

True or false: We can have deficits in forming new declarative memories, while (mostly) sparing existing memories and procedural memory.

Answer 86

True → the example is patient H.M.