semantic memory

Regular cocoa drinking helps those with MCI

September, 2012

Daily consumption of a high level of cocoa was found to improve cognitive scores, insulin resistance and blood pressure, in older adults with mild cognitive impairment.

Back in 2009, I reported briefly on a large Norwegian study that found that older adults who consumed chocolate, wine, and tea performed significantly better on cognitive tests. The association was assumed to be linked to the flavanols in these products. A new study confirms this finding, and extends it to older adults with mild cognitive impairment.

The study involved 90 older adults with MCI, who consumed either 990 milligrams, 520 mg, or 45 mg of a dairy-based cocoa drink daily for eight weeks. Their diet was restricted to eliminate other sources of flavanols (such as tea, red wine, apples and grapes).

Cognitive assessment at the end of this period revealed that, although scores on the MMSE were similar across all groups, those consuming higher levels of flavanol cocoa took significantly less time to complete Trail Making Tests A and B, and scored significantly higher on the verbal fluency test. Insulin resistance and blood pressure was also lower.

Those with the highest levels of flavanols did better than those on intermediate levels on the cognitive tests. Both did better than those on the lowest levels.

Changes in insulin resistance explained part, but not all, of the cognitive improvement.

One caveat: the group were generally in good health without known cardiovascular disease — thus, not completely representative of all those with MCI.

 

Reference: 

Source: 

Topics: 

tags: 

tags development: 

tags lifestyle: 

tags memworks: 

tags problems: 

Second language processing differs for negative words

June, 2012

A study involving Chinese-English bilinguals shows how words with negative emotional connotations don’t automatically access native translations, while those with positive or neutral emotions do.

Here’s an intriguing study for those interested in how language affects how we think. It’s also of interest to those who speak more than one language or are interested in learning another language, because it deals with the long-debated question as to whether bilinguals working in their non-native language automatically access the native-language representations in long-term memory, or whether they can ‘switch off’ their native language and use only the target language memory codes.

The study follows on from an earlier study by the same researchers that indicated, through the demonstration of hidden priming effects, that bilinguals subconsciously access their first language when reading in their second language. In this new study, 45 university students (15 native English speakers, 15 native Chinese speakers, and 15 Chinese-English bilinguals) were shown two blocks of 90 word pairs. The pairs could have positive emotional value (e.g., honesty-program), negative valence (failure-poet), or neutral valence (aim-carpenter); could be semantically related (virus-bacteria; love-rose) or unrelated (weather-gender). The English or Chinese words were flashed on the screen one at a time, with a brief interval between the first and second word. The students had to indicate whether the second word was related in meaning to the first, and their brain activity was monitored.

The English and Chinese speakers acted as controls — it was the bilinguals, of course, who were the real interest. Some of the English word pairs shared a sound in the Chinese translation. If the Chinese words were automatically activated, therefore, the sound repetition would have a priming effect.

This is indeed what was found (confirming the earlier finding and supporting the idea that native language translations are automatically activated) — but here’s the interesting thing: the priming effect occurred only for positive and neutral words. It did not occur when the bilinguals saw negative words such as war, discomfort, inconvenience, and unfortunate.

The finding, which surprised the researchers, is nonetheless consistent with previous evidence that anger, swearing or discussing intimate feelings has more power in a speaker's native language. Parents, too, tend to speak to their infants in their native tongue. Emotion, it seems, is more strongly linked to our first language.

It’s traditionally thought that second language processing is fundamentally determined by the age of acquisition and the level of proficiency. The differences in emotional resonance have been, naturally enough, attributed to the native language being acquired first. This finding suggests the story is a little more complicated.

The researchers theorize that they have touched on the mechanism by which emotion controls our fundamental thought processes. They suggest that the brain is trying to protect us by minimizing the effect of distressing or disturbing emotional content, by shutting down the unconscious access to the native language (in which the negative words would be more strongly felt).

A few more technical details for those interested:

The Chinese controls demonstrated longer reaction times than the English controls, which suggests (given that 60% of the Chinese word pairs had overt sound repetitions but no semantic relatedness) that this conjunction made the task substantially more difficult. The bilinguals, however, had reaction times comparable to the English controls. The Chinese controls showed no effect of emotional valence, but did show priming effects of the overt sound manipulation that were equal for all emotion conditions.

The native Chinese speakers had recently arrived in Britain to attend an English course. Bilinguals had been exposed to English since the age of 12 and had lived in Britain for an average of 20.5 months.

Reference: 

[2969] Wu, Y J., & Thierry G.
(2012).  How Reading in a Second Language Protects Your Heart.
The Journal of Neuroscience. 32(19), 6485 - 6489.

Source: 

Topics: 

tags memworks: 

tags strategies: 

Sleeping after learning is most effective

May, 2012

A new sleep study confirms the value of running through new material just before bedtime, particularly it seems when that material is being learned using mnemonics or by rote.

We know that we remember more 12 hours after learning if we have slept during that 12 hours rather than been awake throughout, but is this because sleep is actively helping us remember, or because being awake makes it harder to remember (because of interference and over-writing from other experiences). A new study aimed to disentangle these effects.

In the study, 207 students were randomly assigned to study 40 related or unrelated word pairs at 9 a.m. or 9 p.m., returning for testing either 30 minutes, 12 hours or 24 hours later.

As expected, at the 12-hour retest, those who had had a night’s sleep (Evening group) remembered more than those who had spent the 12 hours awake (Morning group). But this result was because memory for unrelated word pairs had deteriorated badly during 12 hours of wakefulness; performance on the related pairs was the same for the two groups. Performance on the related and unrelated pairs was the same for those who slept.

For those tested at 24 hours (participants from both groups having received both a full night of sleep and a full day of wakefulness), those in the Evening group (who had slept before experiencing a full day’s wakefulness) remembered significantly more than the Morning group. Specifically, the Evening group showed a very slight improvement over training, while the Morning group showed a pronounced deterioration.

This time, both groups showed a difference for related versus unrelated pairs: the Evening group showed some deterioration for unrelated pairs and a slightly larger improvement for related pairs; the Morning group showed a very small deterioration for related pairs and a much greater one for unrelated pairs. The difference between recall of related pairs and recall of unrelated pairs was, however, about the same for both groups.

In other words, unrelated pairs are just that much harder to learn than related ones (which we already know) — over time, learning them just before sleep vs learning early in the day doesn’t make any difference to that essential truth. But the former strategy will produce better learning for both types of information.

A comparison of the 12-hour and 24-hour results (this is the bit that will help us disentangle the effects of sleep and wakefulness) reveals that twice as much forgetting of unrelated pairs occurred during wakefulness in the first 12 hours, compared to wakefulness in the second 12 hours (after sleep), and 3.4 times more forgetting of related pairs (although this didn’t reach significance, the amount of forgetting being so much smaller).

In other words, sleep appears to slow the rate of forgetting that will occur when you are next awake; it stabilizes and thus protects the memories. But the amount of forgetting that occurred during sleep was the same for both word types, and the same whether that sleep occurred in the first 12 hours or the second.

Participants in the Morning and Evening groups took a similar number of training trials to reach criterion (60% correct), and there was no difference in the time it took to learn unrelated compared to related word pairs.

It’s worth noting that there was no difference between the two groups, or for the type of word pair, at the 30-minutes test either. In other words, your ability to remember something shortly after learning it is not a good guide for whether you have learned it ‘properly’, i.e., as an enduring memory.

The study tells us that the different types of information are differentially affected by wakefulness, that is, perhaps, they are more easily interfered with. This is encouraging, because semantically related information is far more common than unrelated information! But this may well serve as a reminder that integrating new material — making sure it is well understood and embedded into your existing database — is vital for effective learning.

The findings also confirm earlier evidence that running through any information (or skills) you want to learn just before going to bed is a good idea — and this is especially true if you are trying to learn information that is more arbitrary or less well understood (i.e., the sort of information for which you are likely to use mnemonic strategies, or, horror of horrors, rote repetition).

Reference: 

Source: 

Topics: 

tags lifestyle: 

tags memworks: 

tags strategies: 

Gestures improve language learning

February, 2012

Those learning a new language benefit from making suitable gestures as they repeat new vocabulary, and this can even extend to gestures arbitrarily linked to abstract adverbs.

I always like gesture studies. I think I’m probably right in saying that they started with language learning. Way back in 1980 it was shown that acting out action phrases meant they were remembered better than if the phrases had been only heard or read (the “enactment effect”). Enacted items, it turned out, “popped out” effortlessly in free recall tests — in other words, enactment had made the phrases highly accessible. Subsequent research found that this effect occurred both for both older and younger adults, and in immediate and delayed recall tests — suggesting not only that such items are more accessible but that forgetting is slower.

Following these demonstrations, there have been a few studies that have specifically looked at the effect of gestures on learning foreign languages, which have confirmed the benefits of gestures. But there are various confounding factors that are hard to remove when using natural languages, which is why the present researchers have developed an artificial language (“Vimmi”) to use in their research. In their first study, as in most other studies, the words and phrases used related to actions. In a new study, the findings were extended to more abstract vocabulary.

In this study, 20 German-speakers participated in a six-day language class to study Vimmi. The training material included 32 sentences, each containing a subject, verb, adverb, and object. While the subject nouns were concrete agents (e.g., musician, director), the other words were all abstract. Here’s a couple of sample sentences (translated, obviously): (The) designer frequently shapes (the) style. (The) pilot really enjoys (the) view. The length of the words was controlled: nouns all had 3 syllables; verbs and adverbs all had two.

For 16 of the sentences, participants saw the word in Vimmi and heard it. The translation of the word appeared on the screen fractionally later, while at the same time a video appeared in which woman performed the gesture relating to the word. The audio of the word was replayed, and participants were cued to imitate the gesture as they repeated the word. For the other 16 sentences, a video with a still image of the actress appeared, and the participants were simply cued to repeat the word when the audio was replayed.

While many of the words used gestures similar to their meaning (such as a cutting gesture for the word “cut”), the researchers found that the use of any gesture made a difference as long as it was unique and connected to a specific word. For example, the abstract word “rather” does not have an obvious gesture that would go with it. However, a gesture attached to this word also worked.

Each daily session lasted three hours. From day 2, sessions began with a free recall and a cued recall test. In the free recall test, participants were asked to write as many items as possible in both German and Vimmi. Items had to be perfectly correct to be counted. From day 4, participants were also required to produce new sentences with the words they had learned.

Right from the beginning, free recall of items which had been enacted was superior to those which hadn’t been — in German. However, in Vimmi, significant benefits from enactment occurred only from day 3. The main problem here was not forgetting the items, but correctly spelling them. In the cued recall test (translating from Vimmi to German, or German to Vimmi), again, the superiority of the enactment condition only showed up from day 3.

Perhaps the most interesting result came from the written production test. Here, people reproduced the same number of sentences they had learned on each of the three days of the test, and although enacted words were remembered at a higher rate, that rate didn’t alter, and didn’t reach significance. However, the production of new sentences improved each day, and the benefits of enactment increased each day. These benefits were significant from day 5.

The main question, however, was whether the benefits of enactment depended on word category. As expected, concrete nouns were remembered than verbs, followed by abstract nouns, and finally adverbs. When all the tests were lumped together, there was a significant benefit of enactment for all types of word. However, the situation became a little more nuanced when the data was separately analyzed.

In free recall, for Vimmi, enactment was only of significant benefit for concrete nouns and verbs. In cued recall, for translating German into Vimmi, the enactment benefit was significant for all except concrete nouns (I’m guessing concrete nouns have enough ‘natural’ power not to need gestures in this situation). For translating Vimmi into German, the benefit was only significant for verbs and abstract nouns. In new sentence production, interestingly, participants used significantly more items of all four categories if they had been enacted. This is perhaps the best evidence that enactment makes items more accessible in memory.

What all this suggests is that acting out new words helps you learn them, but some types of words may benefit more from this strategy than others. But I think we need more research before being sure about such subtleties. The pattern of results make it clear that we really need longer training, and longer delays, to get a better picture of the most effective way to use this strategy.

For example, it may be that adverbs, although they showed the most inconsistent benefits, are potentially the category that stands to gain the most from this strategy — because they are the hardest type of word to remember. Because any embodiment of such an abstract adverb must be arbitrary — symbolic rather than representational — it naturally is going to be harder to learn (yes, some adverbs could be represented, but the ones used in this study, and the ones I am talking about, are of the “rather”, “really”, “otherwise” ilk). But if you persist in learning the association between concept and gesture, you may derive greater benefit from enactment than you would from easier words, which need less help.

Here’s a practical discussion of all this from a language teacher’s perspective.

Reference: 

[2688] Macedonia, M., & Knösche T. R.
(2011).  Body in Mind: How Gestures Empower Foreign Language Learning.
Mind, Brain, and Education. 5(4), 196 - 211.

Source: 

Topics: 

tags memworks: 

tags strategies: 

Memory fitness program improves memory abilities of oldest adults

October, 2011

A six-week memory fitness program offered to older adults helped improve their ability to recognize and recall words.

In a study involving 115 seniors (average age 81), those who participated in a six-week, 12-session memory training program significantly improved their verbal memory. 15-20 seniors participated in each hour-long class, which included explanations of how memory works, quick strategies for remembering names, faces and numbers, basic memory strategies such as linking ideas and creating visual images, and information on a healthy lifestyle for protecting and maintaining memory.

Most of the study participants were women, Caucasian and had attained a college degree or higher level of education.

Reference: 

[2491] Miller, K. J., Siddarth P., Gaines J. M., Parrish J. M., Ercoli L. M., Marx K., et al.
(2011).  The Memory Fitness Program.
American Journal of Geriatric Psychiatry. 1 - 1.

Source: 

Topics: 

tags development: 

tags memworks: 

tags problems: 

tags strategies: 

Preventing interference between topics or skills

September, 2011

Learning two tasks or subjects one after another typically leads to poorer remembering of the first. A new study indicates the cause and suggests a remedy.

Trying to learn two different things one after another is challenging. Almost always some of the information from the first topic or task gets lost. Why does this happen? A new study suggests the problem occurs when the two information-sets interact, and demonstrates that disrupting that interaction prevents interference. (The study is a little complicated, but bear with me, or skip to the bottom for my conclusions.)

In the study, young adults learned two memory tasks back-to-back: a list of words, and a finger-tapping motor skills task. Immediately afterwards, they received either sham stimulation or real transcranial magnetic stimulation to the dorsolateral prefrontal cortex or the primary motor cortex. Twelve hours later the same day, they were re-tested.

As expected from previous research, word recall (being the first-learned task) declined in the control condition (sham stimulation), and this decline correlated with initial skill in the motor task. That is, the better they were at the second task, the more they forgot from the first task. This same pattern occurred among those whose motor cortex had been stimulated. However, there was no significant decrease in word recall for those who had received TMS to the dorsolateral prefrontal cortex.

Learning of the motor skill didn't differ between the three groups, indicating that this effect wasn't due to a disruption of the second task. Rather, it seems that the two tasks were interacting, and TMS to the DLPFC disrupted that interaction. This hypothesis was supported when the motor learning task was replaced by a motor performance task, which shouldn’t interfere with the word-learning task (the motor performance task was almost identical to the motor learning task except that it didn’t have a repeating sequence that could be learned). In this situation, TMS to the DLPFC produced a decrease in word recall (as it did in the other conditions, and as it would after a word-learning task without any other task following).

In the second set of experiments, the order of the motor and word tasks was reversed. Similar results occurred, with this time stimulation to the motor cortex being the effective intervention. In this case, there was a significant increase in motor skill on re-testing — which is what normally happens when a motor skill is learned on its own, without interference from another task (see my blog post on Mempowered for more on this). The word-learning task was then replaced with a vowel-counting task, which produced a non-significant trend toward a decrease in motor skill learning when TMS was applied to the motor cortex.

The effect of TMS depends on the activity in the region at the time of application. In this case, TMS was applied to the primary motor cortex and the DLPFC in the right hemisphere, because the right hemisphere is thought to be involved in integrating different types of information. The timing of the stimulation was critical: not during learning, and long before testing. The timing was designed to maximize any effects on interference between the two tasks.

The effect in this case mimics that of sleep — sleeping between tasks reduces interference between them. It’s suggested that both TMS and sleep reduce interference by reducing the communication between the prefrontal cortex and the mediotemporal lobe (of which the hippocampus is a part).

Here’s the problem: we're consolidating one set of memories while encoding another. So, we can do both at the same time, but as with any multitasking, one task is going to be done better than the other. Unsurprisingly, encoding appears to have priority over consolidation.

So something needs to regulate the activity of these two concurrent processes. Maybe something looks for commonalities between two actions occurring at the same time — this is, after all, what we’re programmed to do: we link things that occur together in space and time. So why shouldn’t that occur at this level too? Something’s just happened, and now something else is happening, and chances are they’re connected. So something in our brain works on that.

If the two events/sets of information are connected, that’s a good thing. If they’re not, we get interference, and loss of data.

So when we apply TMS to the prefrontal cortex, that integrating processor is perhaps disrupted.

The situation may be a little different where the motor task is followed by the word-list, because motor skill consolidation (during wakefulness at least) may not depend on the hippocampus (although declarative encoding does). However, the primary motor cortex may act as a bridge between motor skills and declarative memories (think of how we gesture when we explain something), and so it may this region that provides a place where the two types of information can interact (and thus interfere with each other).

In other words, the important thing appears to be whether consolidation of the first task occurs in a region where the two sets of information can interact. If it does, and assuming you don’t want the two information-sets to interact, then you want to disrupt that interaction.

Applying TMS is not, of course, a practical strategy for most of us! But the findings do suggest an approach to reducing interference. Sleep is one way, and even brief 20-minute naps have been shown to help learning. An intriguing speculation (I just throw this out) is that meditation might act similarly (rather like a sorbet between courses, clearing the palate).

Failing a way to disrupt the interaction, you might take this as a warning that it’s best to give your brain time to consolidate one lot of information before embarking on an unrelated set — even if it's in what appears to be a completely unrelated domain. This is particularly so as we get older, because consolidation appears to take longer as we age. For children, on the other hand, this is not such a worry. (See my blog post on Mempowered for more on this.)

Reference: 

[2338] Cohen, D. A., & Robertson E. M.
(2011).  Preventing interference between different memory tasks.
Nat Neurosci. 14(8), 953 - 955.

Source: 

Topics: 

tags memworks: 

tags strategies: 

Bilingualism helps early development of executive control

August, 2011

A study of Korean preschoolers demonstrates that at least some of the cognitive benefits of bilingualism are due to learning two languages, not because of a more diligent culture or a more enriched environment.

An increasing number of studies have been showing the benefits of bilingualism, both for children and in old age. However, there’s debate over whether the apparent benefits for children are real, or a product of cultural (“Asians work harder!” or more seriously, are taught more behavioral control from an early age) or environmental factors (such as socioeconomic status).

A new study aimed to disentangle these complicating factors, by choosing 56 4-year-olds with college-educated parents, from middle-class neighborhoods, and comparing English-speaking U.S. children, Korean-speaking children in the U.S. and in Korea, and Korean-English bilingual children in the U.S.

The children were tested on a computer-game-like activity designed to assess the alerting, orienting, and executive control components of executive attention (a child version of the Attention Network Test). They were also given a vocabulary test (the Peabody Picture Vocabulary Test-III) in their own language, if monolingual, or in English for the bilinguals.

As expected, given their young age, English monolinguals scored well above bilinguals (learning more than one language slows the acquisition of vocabulary in the short-term). Interestingly, however, while Korean monolinguals in Korea performed at a comparable level to the English monolinguals, Korean monolinguals in the U.S. performed at the level of the bilinguals. In other words, the monolinguals living in a country where their language is a majority language have comparable language skills, and those living in a country in which their primary language is a minority language have similar, and worse, language skills.

That’s interesting, but the primary purpose of the study was to look at executive control. And here the bilingual children shone over the monolinguals. Specifically, the bilingual children were significantly more accurate on the attention test than the monolingual Koreans in the U.S. (whether they spoke Korean or English). Although their performance in terms of accuracy was not significantly different from that of the monolingual children in Korea, these children obtained their high accuracy at the expense of speed. The bilinguals were both accurate and fast, suggesting a different mechanism is at work.

The findings confirm earlier research indicating that bilingualism, independent of culture, helps develop executive attention, and points to how early this advantage begins.

The Korean-only and bilingual children from the United States had first generation native Korean parents. The bilingual children had about 11 months of formal exposure to English through a bilingual daycare program, resulting in them spending roughly 45% of their time using Korean (at home and in the community) and 55% of their time using English (at daycare). The children in Korea belonged to a daycare center that did offer a weekly 15-minute session during which they were exposed to English through educational DVDs, but their understanding of English was minimal. Similarly, the Korean-only children in the U.S. would have had some exposure to English, but it was insufficient to allow them to understand English instructions. The researchers’ informal observation of the Korean daycare center and the ones in the U.S. was that the programs were quite similar, and neither was more enriching.

Reference: 

[2351] Yang, S., Yang H., & Lust B.
(2011).  Early Childhood Bilingualism Leads to Advances in Executive Attention: Dissociating Culture and Language.
Bilingualism: Language and Cognition. 14(03), 412 - 422.

Source: 

Topics: 

tags development: 

tags memworks: 

tags strategies: 

Young binge drinkers less able to learn new verbal information

July, 2011

Binge drinking university students, regardless of gender, performed more poorly on tests of verbal memory, but not on a test of visual memory.

Following animal research indicating that binge drinking damages the hippocampus, and other research showing that this learning and memory center is still developing during adolescence, a new study has investigated the effects of binge drinking on learning in university students. The study, involving 122 Spanish university students (aged 18-20), of whom half engaged in binge drinking, found a clear association between binge drinking and a lower ability to learn new verbal information.

Specifically, binge drinkers were more affected by interference in the Rey Auditory Verbal Learning Test, and remembered fewer words; they also performed worse on the Weschler Memory Scale-3rd ed. (WMS-III) Logical Memory subtest, both on immediate and delayed recall. However, there were no differences between the two groups on the WMS-III Family Pictures subtest (measuring visual declarative memory).

These results persisted even after controlling for other possible confounding variables such as intellectual levels, history of neurological or psychopathological disorders, other drug use, or family history of alcoholism.

The genders were evenly represented in both groups. Interestingly, and in contradiction of some other research, women were not found to be more vulnerable to the neurotoxic effects of binge drinking.

Reference: 

[2298] Parada, M., Corral M., Caamaño‐Isorna F., Mota N., Crego A., Holguín S R., et al.
(Submitted).  Binge Drinking and Declarative Memory in University Students.
Alcoholism: Clinical and Experimental Research.

Source: 

Topics: 

tags development: 

tags lifestyle: 

tags memworks: 

People are poor at predicting their learning

April, 2011

A series of online experiments demonstrate that beliefs about memory, judgments of how likely you are to remember, and actual memory performance, are all largely independent of each other.

Research has shown that people are generally poor at predicting how likely they are to remember something. A recent study tested the theory that the reason we’re so often inaccurate is that we make predictions about memory based on how we feel while we're encountering the information to be learned, and that can lead us astray.

In three experiments, each involving about 80 participants ranging in age from late teens to senior citizens, participants were serially shown words in large or small fonts and asked to predict how well they'd remember each (actual font sizes depended on the participants’ browsers, since this was an online experiment and participants were in their own homes, but the larger size was four times larger than the other).

In the first experiment, each word was presented either once or twice, and participants were told if they would have another chance to study the word. The length of time the word was displayed on the first occasion was controlled by the participant. On the second occasion, words were displayed for four seconds, and participants weren’t asked to make a new prediction. At the end of the study phase, they had two minutes to type as many words as they remembered.

Recall was significantly better when an item was seen twice. Recall wasn’t affected by font size, but participants were significantly more likely to believe they’d recall those presented in larger fonts. While participants realized seeing an item twice would lead to greater recall, they greatly underestimated the benefits.

Because people so grossly discounted the benefit of a single repetition, in the next experiment the comparison was between one and four study trials. This time, participants gave more weight to having three repetitions versus none, but nevertheless, their predictions were still well below the actual benefits of the repetitions.

In the third experiment, participants were given a simplified description of the first experiment and either asked what effect they’d expect font size to have, or what effect having two study trials would have. The results (similar levels of belief in the benefits of each condition) neither resembled the results in the first experiment (indicating that those people’s predictions hadn’t been made on the basis of their beliefs about memory effects), or the actual performance (demonstrating that people really aren’t very good at predicting their memory performance).

These findings were confirmed in a further experiment, in which participants were asked about both variables (rather than just one).

The findings confirm other evidence that (a) general memory knowledge tends to be poor, (b) personal memory awareness tends to be poor, and (c) ease of processing is commonly used as a heuristic to predict whether something will be remembered.

 

Addendum: a nice general article on this topic by the lead researcher Nate Kornell has just come out in Miller-McCune

Reference: 

Kornell, N., Rhodes, M. G., Castel, A. D., & Tauber, S. K. (in press). The ease of processing heuristic and the stability bias: Dissociating memory, memory beliefs, and memory judgments. Psychological Science.

Source: 

Topics: 

tags memworks: 

tags strategies: 

tags study: 

Role of expectation on memory consolidation during sleep

March, 2011

A new study suggests sleep’s benefits for memory consolidation depend on you wanting to remember.

Two experiments involving a total of 191 volunteers have investigated the parameters of sleep’s effect on learning. In the first experiment, people learned 40 pairs of words, while in the second experiment, subjects played a card game matching pictures of animals and objects, and also practiced sequences of finger taps. In both groups, half the volunteers were told immediately following the tasks that they would be tested in 10 hours. Some of the participants slept during this time.

As expected, those that slept performed better on the tests (all of them: word recall, visuospatial, and procedural motor memory), but the really interesting bit is that it turned out it was only the people who slept who also knew a test was coming that had improved memory recall. These people showed greater brain activity during deep or "slow wave" sleep, and for these people only, the greater the activity during slow-wave sleep, the better their recall.

Those who didn’t sleep, however, were unaffected by whether they knew there would be a test or not.

Of course, this doesn’t mean you never remember things you don’t intend or want to remember! There is more than one process going on in the encoding and storing of our memories. However, it does confirm the importance of intention, and cast light perhaps on some of your learning failures.

Reference: 

[2148] Wilhelm, I., Diekelmann S., Molzow I., Ayoub A., Mölle M., & Born J.
(2011).  Sleep Selectively Enhances Memory Expected to Be of Future Relevance.
The Journal of Neuroscience. 31(5), 1563 - 1569.

Source: 

Topics: 

tags lifestyle: 

tags memworks: 

Pages

Subscribe to RSS - semantic memory