memory consolidation

Question 1

what did Mueller & Pulzecker 1900 do

Answer 1

• New memories initially fragile, but soon resistant to interference.
• Ss learnt a list of paired-associate syllables (AB) and were tested in cued recall (using the first syllable, A).
• Interpolating another list (CD) impaired memory of the first list (AB).
• Found temporal gradient, whereby the closer in time the interfering list to the target list, the stronger its amnestic effect.

Question 2

types of memory consolidation

Answer 2

1. Cellular (synaptic)

2. System-level (whole brain)

Question 3

what did Mueller & Pilzecker conclude

Answer 3

• Memories require time to consolidate.
• Retroactive interference compromises the integrity of recently formed—but not yet consolidated— memories.
• Interference is ‘nonspecific’, i.e. the interfering material does not have to be similar to the target material (i.e., AB vs. CD).
• Mental exertion is the interfering force.

Question 4

what did Wixted say about the shape of forgetting

Answer 4

• The clay metaphor, i.e., the idea that memories become more and more resistant to interference fits well with forgetting curves.
• The rate with which we forget is not constant; this would be exactly the property of memoryless systems

Question 5

what did Ebbinghaus (1885) argue

Answer 5

• Ebbinghaus (1885): the forgetting function is such that we forget less and less as time goes by.

Question 6

what did Jost 1897 argue

Answer 6

• Jost (1897): If two memories have equal strength but different ages, the older trace will decay at a slower rate.

Question 7

continuous reduction in the forgetting rate is a sign of…

Answer 7

continuous reduction in the forgetting rate is a sign of consolidation

Question 8

what is cellular consolidation

Answer 8

• Occurs at the neuron level (not at the whole-brain “systems” level)
• Takes place during the first hours (and perhaps days) after initial memory formation in the hippocampus
• Fits well with the idea of a trace-hardening physiological process put forward as far as Mueller and Pilzecker
• Corresponds to the discovery of long-term potentiation (Bliss & Lømo, 1973)

Question 9

what is Long-term potentiation (Bliss & Lømo, 1973)

Answer 9

• Long-lasting enhancement of synaptic efficacy induced by a tetanus (short burst of high-frequency stimulation) to the presynaptic neuron.

Question 10

what amnesia did HM hae

Answer 10

anterograde amnesia and temporally graded retrograde amnesia

Question 11

what is anterograde amnesia

Answer 11

anterograde amnesia: inability to form new declarative memories (the ‘what’)

Question 12

what is temporally graded retrograde amnesia

Answer 12

temporally graded retrograde amnesia: impairment of memories formed prior to surgery, stronger for young than old memories (Scoville & Milner, 1957) (Ribot’s law, 1881).

Question 13

what is systems consolidation

Answer 13

• Declarative memories becoming independent from the hippocampus and more dependent on the neocortex is referred as ‘systems consolidation’.

Question 14

what did Bayley et al 2006 find

Answer 14

Bayley et al. (2006; Manns et al. 2003): 6 amnesic patients with damage limited to the hippocampal region.

Asked Ps about news (1951-2005). Performance with controls and patients is shown right. Old memories are preserved in patients because they have had time to be cloned and presented elsewhere in the brain. The new events has worse performance in patients. However, for most memories, they are the same level as controls.

Question 15

what did Smith adn Squire 2009 do

Answer 15

160 questions on news events over 30 years

There is a stronger hippocamus activation for newer memories. Older memories show activation in the neo-cortex

Question 16

what did takashima do

Answer 16

Takashima et al had paired learning protocol. You have to associate a given face with a given orientation of an arrow (shown in B). this is training phase. The test phase is the following day. They need to identify the correct orientation of the face. They got a set of faces leanrt on day one and another group learnt just before the test on day two. The list learnt on day 1 is old. The list learnt before the test is new. They have manipulated age of the memories. Over the course of 24 hours, the memories engage with the hippocampus less but the neo-cortex more.

Question 17

What is the significance of shift from the hippocampus (in the medial-temporal lobe) to the neocortex?

Answer 17

• Declarative memories stored in neocortex from the outset (e.g., sensory and semantic areas)
• Hippocampus acts as a relay station and binds them together.
• Over time, cortico-cortical associations develop, such that these memories become independent of the hippocampus.

Question 18

what are complementary learning systems (Marr 1971, McClelland et al, 1995)

Answer 18

a) A fast learning system that holds information only temporarily (medial temporal lobe, i.e., the hippocampus)
b) A slow learning system that serves as long-term store (i.e., the neocortex)

Question 19

• Information initially stored in the hippocampus is progressively fed back into the neocortex (via ??????

Answer 19

• Information initially stored in the hippocampus is progressively fed back into the neocortex (via ‘neural replay’),

Question 20

As both systems (fast and slow) are used to encode new learning, this reactivation/redistribution has to occur ……………

Answer 20

As both systems are used to encode new learning, this reactivation/redistribution has to occur offline, for instance during sleep.

Question 21

types of declarative memory

Answer 21

episodic and semantic

Question 22

types of non-declarative memory

Answer 22

procederal skill, conditioning, non-associative, priming

Question 23

what did Jenkins & Dallenbach 1924 do

Answer 23

Two subjects learn lists of 10 nonsense syllables until mastered

Re-tested in free recall after a varyign time interval (1,2,4 and 8hrs) filled with sleep or wake

Question 24

what did Jenkins & Dallenbach 1924 find

Answer 24

sleep protects against forgetting

however, absence of interference is not the whole story

time of training has an influence

need less exposure in the evening than the morning for complete mastery

Question 25

what did Payne 2012 find with the sleep-first effect

Answer 25

• Learning of related (‘circus-clown’) or unrelated pairs (‘cactus-brick’) using study-test cycles with feedback until 24 out of 40 correct.
• After 12 hrs, better performance for the sleep group, only for unrelated pairs.
• Temporal gradient a retroactive facilitation: after 24 hrs, better recall for those who slept first!
• Both absence of interference and system consolidation during SWS could be behind the effect, though logically cellular consolidation should be blind to semantic relatedness.

Question 26

what is the sleep-first effect

Answer 26

• Temporal gradient a retroactive facilitation: after 24 hrs, better recall for those who slept first! Less forgetting than later sleeping

Question 27

how do u explain sleep-first effect

Answer 27

• Both absence of interference and system consolidation during SWS could be behind the effect, though logically cellular consolidation should be blind to semantic relatedness.

Question 28

what did Plihal and Born do

Answer 28

tested the differential effect of sleep composition

compared declarative and procederal memory

Question 29

what did Plihal and Born find

Answer 29

• Double dissociation: declarative memory promoted by slow wave sleep; motor skills improved by REM-sleep

Question 30

what did Plihal and Born find about declarative memory

Answer 30

it is promoted by slow wave sleep

Question 31

what did Plihal and Born find about motor skills

Answer 31

motor skills are improved by REM sleep

Question 32

what do we know about neural replay

Answer 32

(Maquet et al. 2000; Wilson & McNaughton, 1994; Rasch et al. 2007)

• Over a 24-hr period, there are privileged moments (perhaps when not much encoding is happening) during which the brain spontaneously replays to itself information recently acquired.
• Done mostly unconsciously, though some of it could reach consciousness.
• Allows other brain regions to learn the information in question.
• Slow-wave sleep (SWS) appears as a key window.

Question 33

According to the model of systems consolidation put forward by Born and Wilhelm (2013), during slow-wave sleep…

Answer 33

According to the model of systems consolidation put forward by Born and Wilhelm (2013), during slow-wave sleep, slow oscillations occurring in neocortical regions constitutes a signal sent via the thalamus to the hippocampus to reactivate hippocampal memories.

Question 34

neocortical oscillations drive ……………..

Answer 34

neocortical oscillations drive thalamo-corticol spindles, which themselves drive spindle-ripple events in the hippocampus: the alignment between levels is strong and controlled always by the troughs at the level immediately above.

Question 35

what did Rash et al 2007 say about ‘cuing’

Answer 35

• Cued reactivation using an odour also present during the learning phase.
• Used spatial memory as skill.
• Re-exposure to associated odour during slow-wave sleep reactivated hippocampal areas active during learning
• Also led to enhanced memory performance the next day.

Question 36

what is neural replay

Answer 36

During sleep or awake rest, replay refers to the re-occurrence of a sequence of cell activations that also occurred during activity, but the replay has a much faster time scale. It may be in the same order, or in reverse.

Question 37

what Dumay’s reply to Schreiner and Rasch 2018

Answer 37

• Net performance (i.e., sums, %) hides the presence of two opposing forces at the item-level: forgetting (inability to recollect previous knowledge) and reminiscence (ability to access knowledge inaccessible until then).
• The usual decline in performance smaller after sleep than after wake does not mean that sleep just prevents forgetting.

Question 38

what did Payne et al 2009 do?

Answer 38

Ss learns 8 lists of 12 semantically related words, all strongly associated with a missing critical target. E.g., door, glass, pane, […] for WINDOW

Question 39

what did Payne et al 2009 find?

Answer 39

Sleeping on information returns better free recall. The duration of sleep, provides enough substrate to boost performance. Napping may not be as strong (bottom graphs).

Sleep strengthens associations between individual memory elements, and fills in the gaps!
Sleep integrates new information with long-consolidated knowledge

Question 40

what did Dumay 2007 predict

Answer 40

They predicted, before sleep, you may have learnt ‘cathedral’ to a strong level. This declarative knowledge will not have a procedural effect on how cathedral is recognised. After sleep, cathedral could impede the recognition of other words. An indirect effect of learning

Question 41

what did Dumay 2007 do

Answer 41

There is a difference between two conditions: exposure to cathedruke and cathedral; only exposure to cathedral. The task is given to Ps right after training. Those who slept on the new learning showed a hinderence on how they can perceive the English word ‘cathedral’. Those who were awake saw no change even if they saw ‘cathedruke’.

Question 42

what did Dumay 2007 find with declarative tasks

Answer 42

In declarative tasks, Ps had to recall the words they were taught as a safety measure, the group that slept first is the PM group. Their declarative expression improves as they are doing the task a second time so are used to it. They also have knowledge of the words
The group that doesn’t sleep has foggiting; they have lost information. After sleep, they have improved in memory. PM group then remains awake but can increase performance by 24 hours.

If you improve a lot in declarative measure in the interval, there tend to be more interference from the novel word onto the existing words. So, declarative memories are connected as participants were good consolidators on more than one level.

Question 43

what did Dumay et al 2007 conclude about declarative tasks

Answer 43

If you improve a lot in declarative measure in the interval, there tend to be more interference from the novel word onto the existing words. So, declarative memories are connected as participants were good consolidators on more than one level.

Question 44

what did Wagner, Gais and Born do?

Answer 44

Examined whether sleep preferentially enhances memory for emotional narratives.
• Ss memorized the details of two small descriptions (incl. 94 content words): e.g. “manufacturing bronze sculptures” vs. “child murdering”.
• Ps were trained & woken at 22:25 or 02:15. The latter group would then sleep on the learnt material with sleep composition favouring REM sleep
• Number of content words type-recalled was the memory measure.

Question 45

what did Wagner, Gais and Born find?

Answer 45

• REM sleep enhances, favourable, content with emotion. Sleeping does not differentiate between emotional and neutral memories in the early night. In the late night, emotional memories are boosted.
• Text retention, especially if content was emotional, benefitted more from late night sleep!
• Like the weapon effect, memories are shown as reproducing certain aspects- some are remembered more than others.
• Weapon effect could be occurring immediately. There is amplification of this affect over time oversleep

Question 46

what did Payne et al do on sleep enhancing memory

Answer 46

• Looked at the role of sleep on memory for object and background components of scenes.
• Main components either negative or neutral, whereas background always neutral.

Question 47

what did Payne et al find on sleep enhancing memory

Answer 47

If there is an alarming element, may be consolidating this and losing neutral elements of the scene. Without the alarm, you may consolidate the main object of attention and the background equally.
-Sleep enhanced recognition memory for emotional components to the detriment of background details.
Your memory is better after sleep than initially for the negative aspect of the scene. The neutral element starts to suffer. You can boost the memory after exposure if you sleep. But not if you stay awake.
-No such overnight trade-off for neutral scenes!

Question 48

what was Dumay’s study on ‘setting the alarm’

Answer 48

• -This study examined whether memory consolidation gives neutral cues the power to grab attention after they co-occurred in the context of threat.
• Will surrounding emotions taint something that is originally neutral? Will the word itself become alarming?
• Participants learnt one set of associations between a made-up word and a neutral or emotional picture 7 days before the test, and another set on the day of test.

Question 49

what was Dumay’s results on ‘setting the alarm’

Answer 49

 There is no difference on the ‘same day’ with neutral and alarming
 After 7 days, the alarming test grabs the attention
 The consolidated set always grabs attention (even in the 0 and 6 hour differences)

o Results for emotional photos in front
 Disturbance effect- cant take decision as immediately as you would. The reaction time is always longer in the emotional condition.
 The decision to press the right button to slow down could be due to disturbing photos
 Therefore, alarming condition was harder to learn

o Evolution of learning
 Learning proceeds in a similar fashion whether in an alarming or neutral context
 Emotional words are NOT harder to learn
 This study shows , with consoldiation, thigns that are at first neutral, might become alarming due to the experiential context
 In clinical setting, why some words are more alarming for certain individuals

Question 50

Protection against forgetting occurs at …

Answer 50

Protection against forgetting occurs at the synaptic and systems levels.

Question 51

Slow wave sleep is characterized by the hippocampus not encoding and by neural replay, which makes it ….

Answer 51

Slow wave sleep is characterized by the hippocampus not encoding and by neural replay, which makes it promote synaptic and systems consolidation.

Question 52

Synaptic consolidation in the hippocampus may depend on …

Answer 52

Synaptic consolidation in the hippocampus may depend on the amount of retroactive interference, meaning that it may not be specific to sleep.

Question 53

Sleep not only prevents forgetting, but it also:

Answer 53

Sleep not only prevents forgetting, but it also: (1) helps recover information, (2) promotes gist extraction, and (3) integrates new information with existing knowledge, amongst other things.

Question 54

Consolidation (via sleep) enhances declarative memory for alarming elements to the detriment of background details. It also …

Answer 54

Consolidation (via sleep) enhances declarative memory for alarming elements to the detriment of background details. It also gives initial neutral cues the power to grab attention once they have co-occurred with threat.

Question 55

The case of HM confirmed the link between anterograde amnesia and retrograde hypermesia

true or false?

Answer 55

FALSE. He did not show anything suggesting a link between encoding new memories and what was learnt before. He demonstrated an inability to learn new elements but stored his past.

Question 56

In Plihal & Born (1997), the split night protocol showed that…
A. Slow wave sleep (SWS) is good for procedural knowledge
B. REM sleep has no effect on memory
C. The sequence SWS plus REM sleep promotes declarative knowledge
D. None of the above

Answer 56

D. None of the above

a. The sleep protocol involves training participants at either 11pm and testing in the middle of the night.
i. The first half of the night is the first aprt of the interval where there is more slow wave-sleep
b. The other training was in the middle of the night and testing at 6am
i. More REM sleep
c. This study varied the materials Ps were trained on
d. SWS improved declarative knowledge compared to being awake in that same interval
e. No effect for REM sleep
f. Mirror tracing of a star
i. No effect of sleep in early night compared to wake but in the effect of REM sleep in the second segment in the night

Question 57

Recollecting memories that were previously inaccessible is called…

Answer 57

Recollecting memories that were previously inaccessible is called… REMINISCENCE

Question 58

The fact that new emotional words do not grab attention after 6hrs of wake is in line with the notion of cellular consolidation-

true or false

Answer 58

FALSE
• The system of the brains structure that will ultimately demonstrate the effect we see after sleep are not about immediate learning
• If there is nothing after 6hrs of wake, there is no synaptic change. This would have shown soon after learning.
o Underlying mechanisms are not about synaptic learning but about something else such as integration effects