Topic 11: Memory & Amnesia Flashcards

Question

Fugue State

Answer 1

Form of memory loss where individuals do not know their former life; they pick up and leave and start a new life somewhere else - DSM; is considered more a psychological disorder because we cannot find an organic cause

Answer 2

-Sudden onset, acute, and short course (i.e., comes on quickly but short-lived = transient) - Loss of old memories and inability to form new memories (a little bit of retrograde and a little bit of antegrade) - Concussion, epilepsy, migraine, hypoglycemia (i.e., a severe drop in blood sugar) - this is a temporary, transient

Answer 3

- Treatment for depression (last resort when other therapies are not working); shocking the brain to "restart electric potentials" - It can produce transient amnesia (a person may have briefly lost of memory, specifically retrograde)

Answer 4

An experiment that studies the affects of ECT (Electroconvulsive Shock Therapy) on memory: - Recalling details about popular TV shows that aired for only one season during different years - Temporally limited retrograde amnesia in 20 patients - Measured before ECT: Notice that the ones that were closer in time to them at that moment recalled quite a few facts; as you move further back in time, they recall fewer facts - Measured after ECT: the number of facts recalled dramatically decreases; this shows that ECT impacts the more recent memories (a theory about recent memories is that they have not been strongly consolidated yet, so they are most vulnerable to disruption. - ECT affects normally recover in 24 hours

Answer 5

Amnesia recovery in the context of Ribot's Law: - there is a time gradient in certain types of amnesia - retrograde amnesia: recent memories are the more likely ones to be lost compared to memories that are more remote and further away - Idea that the older memories tend to be the ones that have been very strongly consolidated at that point, and the more recent ones haven't been strongly consolidated and may be vulnerable to disruption In the image: - @ 5 Months: complete loss of memory of 2 years (RA), and in AA, they have lost the inability to form new memory and recall it - @ 8 Months: In RA, the period of a total loss of memory has shrunken by half, and they now have partial retrograde amnesia for four more years, where it is patchy, so they can recall some things in that period of time. In AA, it shrunk to three months, so it suggests that even though at five months, they could not recall any new information, there might have been a period of time where they WERE consolidating information but just could not recall it - @ 16 Months: total RA is down to 2 weeks, there is still the effects of them not being able to form memories therefore cannot recall it (AA) but since then, the AA has resolved

Answer 6

Amnesia recovery in the context of Ribot's Law: - there is a time gradient in certain types of amnesia - retrograde amnesia: recent memories are the more likely ones to be lost compared to memories that are more remote and further away - Idea that the older memories tend to be the ones that have been very strongly consolidated at that point, and the more recent ones haven't been strongly consolidated and may be vulnerable to disruption In the image: - @ 5 Months: complete loss of memory of 2 years (RA), and in AA, they have lost the inability to form new memory and recall it - @ 8 Months: In RA, the period of a total loss of memory has shrunken by half, and they now have partial retrograde amnesia for four more years, where it is patchy, so they can recall some things in that period of time. In AA, it shrunk to three months, so it suggests that even though at five months, they could not recall any new information, there might have been a period of time where they WERE consolidating information but just could not recall it - @ 16 Months: total RA is down to 2 weeks, there is still the effects of them not being able to form memories and therefore cannot recall it (AA) but since then, the AA has resolved

Answer 7

Task: recognizing faces of individuals who were present across different decades; Ronald Reagan was used in this study. - Nonalcoholic controls do well across all decades - Alcoholic controls develop a trend with impairments in the more current decades, suggesting some in antegrade amnesia while also seeing some impairment in the older information (i.e., retrograde) - Korsakoffs have antegrade and retrograde amnesia; you can stop the damage from continuing, but you cannot full recover (i.e., the damage has been done)

Answer 8

Working memory is a component of short-term memory that involves the temporary storage and manipulation of information. It has two main components: 1. Auditory-verbal working memory: - Phonological store: this is responsible for the temporary storage of verbal information, such as speech sounds, words, and numbers. - Input buffer: this component receives and processes incoming auditory information. - Output buffer: this component is responsible for the production of speech and other verbal responses. 2. Visual-nonverbal working memory: - Visuospatial scratchpad: this is responsible for the temporary storage of visual and spatial information, such as images and locations. - Dorsolateral prefrontal cortex (DLPFC): this region of the brain is involved in the active maintenance and manipulation of working memory information. It plays a critical role in both visual and auditory working memory tasks.

Answer 9

The Delayed Response Paradigm is an experiment that involves testing the role of the Dorsolateral Prefrontal Cortex (DLPFC) in short-term memory (also known as working memory). In this experiment, monkeys with bilateral lesions in their DLPFC are presented with a tray of food that is blocked from their view by a screen. The screen is then removed, and the monkeys have to remember the location of the food in order to successfully retrieve it. This experiment is used to demonstrate the involvement of the DLPFC in short-term memory. - no lesion: can find the food - lesion: monkeys find the food via guessing. There is no memory of where the food was placed. - demonstrates that without those regions in the brain, these monkeys seem to have lost the ability to hold visual location information and store, and we see an impairment of that working memory

Answer 10

The experiment involves training monkeys to fixate their gaze on a particular location on a screen in response to a visual cue. The cue is then removed, and the monkey must maintain its gaze fixation for a certain period, after which a visual stimulus appears at a different location on the screen. The monkey is then required to shift its gaze to the new location of the visual stimulus. - we see a lot of firing at the moment when the monkey must hold its gaze and remember where the second visual cue is; this is because while it is holding its gaze, it must remember where that second cue popped up and then move its eyes when prompted - when the monkey moves their eyes, we see activity again During this experiment, single-cell recording techniques are used to record the activity of neurons in the DLPFC. By analyzing the neural activity patterns during different phases of the experiment, researchers can investigate the role of DLPFC in maintaining working memory and spatial attention. This experiment has been used extensively to study the neural mechanisms of working memory in primates, including humans. We see that the cells are active initially when the queue is presented and that they are highly active during the delay (so they are holding onto that information in working memory) - the DLPFC plays a role in motor planning and in relation to visual information - DLPFC has spatial specificity - DLPFC is a part of that dorsal stream, apart from knowing about where things are located in spaces that play a role in motor planning; then the information continues along the dorsal stream to the prefrontal cortex, so it's about holding the visual information in a shorter term memory store, and it's about location information to help planning motor responding - PREFRONTAL CORTEX AND PLANNING; dorsal within the frontal

Answer 11

In the case of H.M: severe AA, and some RA - Spared ability to hold small amounts of information over brief periods of time suggests that working memory/short-term memory is still intact - cannot form any new long term explicit memory, but seem to have a spared working memory HM can display an immediate recall of a novel string of numbers, suggesting that he has an intact working memory. Digit span task: starting with a 3-digit string, then a 4-digit string, then a 5-digit... as the person gets them correct, they move on to a longer string - every time a string is presented, it is a new string, you are not adding a digit on the previous string - the immediate recall of a novel string of numbers - HM could do this one Extended digit span (HM cannot do this, this requires long-term explicit storage): this one uses the same base and adds a new number onto the end; therefore, the person needs to remember the base and continue to remember the additions - 7+ n task (1634589 + 8; + 2; ….) - involves the long-term memory store (the more you repeat the base, you encode and consolidate the base number) - HM cannot do this because he cannot put the base into the LTM storage - recall that HM has trouble with the hippocampus

Answer 12

The digit span task is a psychological test to assess a person's working memory capacity. In this task, the participant is read a series of numbers and is asked to repeat them back in the same order they were presented. The sequence length gradually increases until the participant can no longer correctly repeat the sequence. For example, in the case of "7 digits 1634589", the participant would read the numbers "1, 6, 3, 4, 5, 8, 9" and have to repeat them back in the same order. If the participant is successful, then the length of the sequence is increased by one digit, and the process is repeated until the participant makes an error. The new sequence is completely new, it does not use the base from the previous numbers used.

Answer 13

The extended digit span task is a variation of the digit span task. In this task, the participant is initially presented with a sequence of seven digits to remember, just like in the standard digit span task. Afterward, the participant is asked to recall the sequence in the correct order. If the participant succeeds, the task continues with a new sequence of eight digits to be remembered and recalled in the correct order. If the participant is successful again, the sequence increases to nine digits, and so on. - involves the long-term memory store (the more you repeat the base, you encode and consolidate the base number) In this task, the digit sequence length starts at seven and increases by one digit on each subsequent trial. The participant's score is the highest number of digits recalled in the correct order across all the trials. This task is used to assess the individual's working memory capacity, as it measures the maximum number of digits that an individual can hold in working memory at any given time.

Answer 14

The Delayed non-match-to-sample (DNMS) task is an experimental paradigm used to study the role of the hippocampus in memory. In this task, monkeys are presented with a visual stimulus, such as an object, and after a delay period, they are presented with two objects. The monkey must choose the object not presented during the initial presentation phase. In the variant of the task where monkeys have a lesioned hippocampus, the monkeys are trained to make eye movements to indicate their choice. The delay period between the initial presentation and the choice phase gradually increases. Monkeys with hippocampal lesions show impaired performance on this task, suggesting that the hippocampus is critical for certain aspects of memory. - if the delay was <15 secs, they can do the task because they are relying on short-term memory - if the delay was >15 secs, this requires the consolidation of information into the longer-term store, which requires the hippocampus so they cannot do well - even without a hippocampus, you can have a working memory

Answer 15

The Mirror Tracing Task is a cognitive task that involves tracing a complex shape or pattern while viewing it in a mirror. The purpose of the task is to test a person's ability to learn and execute a complex motor task with visual feedback that is distorted by a mirror. - Implicit memory task During the task, the participant sits in front of a mirror and traces a shape or pattern that is visible only in the reflection. The mirror inverts the visual feedback, so the participant must use motor control to adjust their movements and effectively "unlearn" their normal motor responses in order to complete the task successfully. - with practice, people get faster and more accurate - HM would get faster and more accurate, although he could not recall doing it; therefore, he was retaining long-term information, but this is not an explicit task (episodic), this task relies on implicit memory (procedural memory) - symptom of retrograde memory

Answer 16

The Mirror Reading Task is a cognitive task that involves reading words or sentences that are reflected in a mirror. The purpose of the task is to test implicit learning, which is learning that occurs unconsciously and without awareness of what has been learned. - implicit memory task - RULE OUT PRACTICE EFFECTS by looking at non-repeated performance; this is when we give them novel lines, and we still see improvements and they are building a skill - in the image, it goes down vertically in this order: Retrograde amnesia, Korsakoff's Syndrome, and then those that have undergone ECT, they all improve - in the control subjects, they improve During the task, the participant is presented with words or sentences that are reflected in a mirror, making them difficult to read. Over time, with repeated exposure, the participant learns to read the words or sentences more quickly and accurately, despite the mirror reversal. This is thought to occur through the formation of implicit memory, in which the learning of the task is encoded and stored unconsciously. Studies have shown that individuals with amnesia can learn and improve their performance on the Mirror Reading Task, even though they have no conscious awareness of the learning. This suggests that implicit memory can still be formed and accessed in individuals with amnesia, even when explicit memory is impaired.

Answer 17

Hippocampal damage & semantic memory - teaching HM new words is semantic memory - in the study, controls and HM was given new words; the idea is that after looking at it a couple of times, you could come up with a definition and a synonym and use it in a sentence - after 20 trials, HM could not do all three and would make a significant amount of errors = he could not learn, showing the impairment of his long-term explicit semantic memory - sparred implicit memory = can rely on the basal ganlia and cerebellum, not only hippocampus; it can be demonstrated through behaviour