Testing - news reports

About these topic collections

I’ve been reporting on memory research for over ten years and these topic pages are simply collections of all the news items I have made on a particular topic. They do not pretend to be in any way exhaustive! I cover far too many areas within memory to come anywhere approaching that. What I aim to do is provide breadth, rather than depth. Outside my own area of cognitive psychology, it is difficult to know how much weight to give to any study (I urge you to read my blog post on what constitutes scientific evidence). That (among other reasons) is why my approach in my news reporting is based predominantly on replication and consistency. It's about the aggregate. So here is the aggregate of those reports I have at one point considered of sufficient interest to discuss. If you know of any research you would like to add to the collection, feel free to write about it in a comment (please provide a reference).

Topic summary to come

A study shows how easily you can affect motivation, producing a significant effect on college test scores, while a large German study finds that motivational and strategy factors, but not intelligence, affects growth in math achievement at high school.

I’ve spoken before about the effects of motivation on test performance. This is displayed in a fascinating study by researchers at the Educational Testing Service, who gave one of their widely-used tests (the ETS Proficiency Profile, short form, plus essay) to 757 students from three institutions: a research university, a master's institution and a community college. Here’s the good bit: students were randomly assigned to groups, each given a different consent form. In the control condition, students were told: “Your answers on the tests and the survey will be used only for research purposes and will not be disclosed to anyone except the research team.” In the “Institutional” condition, the rider was added: “However, your test scores will be averaged with all other students taking the test at your college.” While in the “Personal” condition, they were told instead: “However, your test scores may be released to faculty in your college or to potential employers to evaluate your academic ability.”

No prizes for guessing which of these was more motivating!

Students in the “personal” group performed significantly and consistently better than those in the control group at all three institutions. On the multi-choice part of the test, the personal group performed on average .41 of the standard deviation higher than the control group, and the institutional group performed on average .26 SD higher than the controls. The largest difference was .68 SD. On the essay, the largest effect size was .59 SD. (The reason for the results being reported this way is because the focus of the study was on the use of such tests to assess and compare learning gains by colleges.)

The effect is perhaps less dramatic at the individual level, with the average sophomore score on the multichoice test being 460, compared to 458 and 455, for personal, institutional, and control groups, respectively. Interestingly, this effect was greater at the senior level: 469 vs 466 vs 460. For the essay question, however, the effect was larger: 4.55 vs 4.35 vs 4.21 (sophomore); 4.75 vs 4.37 vs 4.37 (senior). (Note that these scores have been adjusted by college admission scores).

Students also reported on motivation level, and this was found to be a significant predictor of test performance, after controlling for SAT or placement scores.

Student participants had received at least one year of college, or (for community colleges) taken at least three courses.

The findings confirm recently expressed concern that students don’t put their best efforts into low-stakes tests, and that, when such tests are used to make judgments about institutional performance (how much value they add), they may well be significantly misleading, if different institutions are providing different levels of motivation.

On a personal level, of course, the findings may be taken as further confirmation of the importance of non-academic factors in academic achievement. Something looked at more directly in the next study.

Motivation, study habits—not IQ—determine growth in math achievement

Data from a large German longitudinal study assessing math ability in adolescents found that, although intelligence was strongly linked to students' math achievement, this was only in the initial development of competence. The significant predictors of growth in math achievement, however, were motivation and study skills.

Specifically (and excitingly for me, since it supports some of my recurring themes!), at the end of Grade 5, perceived control was a significant positive predictor for growth, and surface learning strategies were a significant negative predictor. ‘Perceived control’ reflects the student’s belief that their grades are under their control, that their efforts matter. ‘Surface learning strategies’ reflect the use of rote memorization/rehearsal strategies rather than ones that encourage understanding. (This is not to say, of course, that these strategies don’t have their place — but they need to be used appropriately).

At the end of Grade 7, however, a slightly different pattern emerged, with intrinsic motivation and deep learning strategies the significant positive predictors of growth, while perceived control and surface learning strategies were no longer significant.

In other words, while intelligence didn’t predict growth at either point, the particular motivational and strategy variables that affected growth were different at different points in time, reflecting, presumably, developmental changes and/or changes in academic demands.

Note that this is not to say that intelligence doesn’t affect math achievement! It is, indeed, a strong predictor — but through its effect on getting the student off to a good start (lifting the starting point) rather than having an ongoing benefit.

There was, sadly but unfortunately consistent with other research, an overall decline in motivation from grade 5 to 7. There was also a smaller decline in strategy use (any strategy! — presumably reflecting the declining motivation).

It’s also worth noting that (also sadly but unsurprisingly) the difference between school types increased over time, with those in the higher track schools making more progress than those in the lowest track.

The last point I want to emphasize is that extrinsic motivation only affected initial levels, not growth. The idea that extrinsic motivation (e.g., wanting good grades) is of only short-term benefit, while intrinsic motivation (e.g., being interested in the subject) is far more durable, is one I have made before, and one that all parents and teachers should pay attention to.

The study involved 3,520 students, following them from grades 5 to 10. The math achievement test was given at the end of each grade, while intelligence and self-reported motivation and strategy use were assessed at the end of grades 5 and 7. Intelligence was assessed using the nonverbal reasoning subtest of Thorndike’s Cognitive Abilities Test (German version). The 42 schools in the study were spread among the three school types: lower-track (Hauptschule), intermediate-track (Realschule), and higher-track (Gymnasium). These school types differ in entrance standards and academic demands.

A large study involving Chicago public school students has found conditions in which rewards offered just before a test significantly improve test performance.

In contradiction of some other recent research, a large new study has found that offering students rewards just before standardized testing can improve test performance dramatically. One important factor in this finding might be the immediate pay-off — students received their rewards right after the test. Another might be in the participants, who were attending low-performing schools.

The study involved 7,000 students in Chicago public schools and school districts in south-suburban Chicago Heights. Older students were given financial rewards, while younger students were offered non-financial rewards such as trophies.

Students took relatively short, standardized diagnostic tests three times a year to determine their grasp of mathematics and English skills. Unusually for this type of research, the students were not told ahead of time of the rewards — the idea was not to see how reward improved study habits, but to assess its direct impact on test performance.

Consistent with other behavioral economics research, the prospect of losing a reward was more motivating than the possibility of receiving a reward — those given money or a trophy to look at while they were tested performed better.

The most important finding was that the rewards only ‘worked’ if they were going to be given immediately after the test. If students were told instead that they would be given the reward sometime later, test performance did not improve.

Follow-up tests showed no negative impact of removing the rewards in successive tests.

Age and type of reward mattered. Elementary school students (who were given nonfinancial rewards) responded more to incentives than high-school students. Younger students have been found to be more responsive to non-monetary rewards than older students. Among high school students, the amount of money involved mattered.

It’s important to note that the students tested had low initial motivation to do well. I would speculate that the timing issue is so critical for these students because distant rewards are meaningless to them. Successful students tend to be more motivated by the prospect of distant rewards (e.g., a good college, a good job).

The finding does demonstrate that a significant factor in a student’s poor performance on tests may simply come from not caring to try.

Whether corrections to students’ misconceptions ‘stick’ depends on the strength of the memory of the correction.

Students come into classrooms filled with inaccurate knowledge they are confident is correct, and overcoming these misconceptions is notoriously difficult. In recent years, research has shown that such false knowledge can be corrected with feedback. The hypercorrection effect, as it has been termed, expresses the finding that when students are more confident of a wrong answer, they are more likely to remember the right answer if corrected.

This is somewhat against intuition and experience, which would suggest that it is harder to correct more confidently held misconceptions.

A new study tells us how to reconcile experimental evidence and belief: false knowledge is more likely to be corrected in the short-term, but also more likely to return once the correction is forgotten.

In the study, 50 undergraduate students were tested on basic science facts. After rating their confidence in each answer, they were told the correct answer. Half the students were then retested almost immediately (after a 6 minute filler task), while the other half were retested a week later.

There were 120 questions in the test. Examples include: What is stored in a camel's hump? How many chromosomes do humans have? What is the driest area on Earth? The average percentage of correct responses on the initial test was 38%, and as expected, for the second test, performance was significantly better on the immediate compared to the delayed (90% vs 71%).

Students who were retested immediately gave the correct answer on 86% of their previous errors, and they were more likely to correct their high-confidence errors than those made with little confidence (the hypercorrection effect). Those retested a week later also showed the hypercorrection effect, albeit at a much lower level: they only corrected 56% of their previous errors. (More precisely, on the immediate test, corrected answers rose from 79% for the lowest confidence level to 92% for the highest confidence. On the delayed test, corrected answers rose from 43% to 70% on the second highest confidence level, 64% for the highest.)

In those instances where students had forgotten the correct answer, they were much more likely to reproduce the original error if their confidence had been high. Indeed, on the immediate test, the same error was rarely repeated, regardless of confidence level (the proportion of repeated errors hovered at 3-4% pretty much across the board). On the delayed test, on the other hand, there was a linear increase, with repeated errors steadily increasing from 14% to 23% as confidence level rose (with the same odd exception — at the second highest confidence level, proportion of repeated errors suddenly fell).

Overall, students were more likely to correct their errors if they remembered their error than if they didn’t (72% vs 65%). Unsurprisingly, those in the immediate group were much more likely to remember their initial errors than those in the delayed group (85% vs 61%).

In other words, it’s all about relative strength of the memories. While high-confidence errors are more likely to be corrected if the correct answer is readily accessible, they are also more likely to be repeated once the correct answer becomes less accessible. The trick to replacing false knowledge, then, is to improve the strength of the correct information.

Thus, as recency fades, you need to engage frequency to make the new memory stronger. So the finding points to the special need for multiple repetition, if you are hoping to correct entrenched false knowledge. The success of immediate testing indicates that properly spaced retrieval practice is probably the best way of replacing incorrect knowledge.

Of course, these findings apply well beyond the classroom!

[2725] Butler, A. C., Fazio L. K., & Marsh E. J. (2011).  The hypercorrection effect persists over a week, but high-confidence errors return. Psychonomic Bulletin & Review. 18(6), 1238 - 1244.

Two studies reaffirm the value of retrieval practice, and suggest how often you need to retrieve each item.

In the first study, undergraduates studied English-Lithuanian word pairs, which were displayed on a screen one by one for 10 seconds. After studying the list, the students practiced retrieving the English words — they had 8 seconds to type in the English word as each Lithuanian word appeared, and those that were correct went to the end of the list to be asked again, and those wrong had to be restudied. Each item was pre-assigned a "criterion level" from one to five — the number of times it needed to be correctly recalled during practice.

In the first experiment, participants took one of four recall tests and one of three recognition tests after a 2-day delay. In the second experiment, in order to eliminate the reminder effect of the recall test, participants were only given a recognition test, after a 1-week delay.

Both experiments found that higher criterion levels led to better memory. More importantly, through the variety of tests, they showed that this occurred on all three kinds of memory tested: associative memory; target memory; cue memory. That is, practicing retrieval of the English word didn’t just improve memory for that word (the target), but also for the Lithuanian word (the cue), and the pairing (association).

While this may seem self-evident to some, it has been thought that only the information being retrieved is strengthened by retrieval practice. The results also emphasize that it is the correct retrieval of the information that improves memory, not the number of times the information is studied.

In a related study, 533 students learned conceptual material via retrieval practice across three experiments. Criterion levels varied from one to four correct retrievals in the initial session. Items also varied in how many subsequent sessions they were exposed to. In one to five testing/relearning sessions, the items were practiced until they were correctly recalled once. Memory was tested one to four months later.

It was found that the number of times items were correctly retrieved on the initial session had a strong initial effect, but this weakened as relearning increased. Relearning had pronounced effects on long-term retention with a relatively minimal cost in terms of additional practice trials.

On the basis of their findings, the researchers recommend that students practice recalling concepts to an initial criterion of three correct recalls and then relearn them three times at widely spaced intervals.

[2457] Vaughn, K. E., & Rawson K. A. (2011).  Diagnosing Criterion-Level Effects on Memory. Psychological Science.

Rawson, K.A. & Dunlosky, J. 2011. Optimizing schedules of retrieval practice for durable and efficient learning: How much is enough? Journal of Experimental Psychology: General, Jun 27, 2011, No Pagination Specified. doi: 10.1037/a0023956

Images designed to arouse strong negative emotion can improve your memory for information you’re learning, if presented immediately after you’ve been tested on it.

In a recent study, 40 undergraduate students learned ten lists of ten pairs of Swahili-English words, with tests after each set of ten. On these tests, each correct answer was followed by an image, either a neutral one or one designed to arouse negative emotions, or by a blank screen. They then did a one-minute multiplication test before moving on to the next section.

On the final test of all 100 Swahili-English pairs, participants did best on items that had been followed by the negative pictures.

In a follow-up experiment, students were shown the images two seconds after successful retrieval. The results were the same.

In the final experiment, the section tests were replaced by a restudying period, where each presentation of a pair was followed by an image or blank screen. The effect did not occur, demonstrating that the effect depends on retrieval.

The study focused on negative emotion because earlier research has found no such memory benefit for positive images (including images designed to be sexually arousing).

The findings emphasize the importance of the immediate period after retrieval, suggesting that this is a fruitful time for manipulations that enhance or impair memory. This is consistent with the idea of reconsolidation — that when information is retrieved from memory, it is in a labile state, able to be changed. Thus, by presenting a negative image when the retrieved memory is still in that state, the memory absorbs some of that new context.

[2340] Finn, B., & Roediger H. L. (2011).  Enhancing Retention Through Reconsolidation. Psychological Science. 22(6), 781 - 786.

A new study shows how stress only impacts math performance in those with both higher working memory capacity and math anxiety, while another shows that whether or not pressure impacts your performance depends on the nature of the pressure and the type of task.

Working memory capacity and level of math anxiety were assessed in 73 undergraduate students, and their level of salivary cortisol was measured both before and after they took a stressful math test.

For those students with low working memory capacity, neither cortisol levels nor math anxiety made much difference to their performance on the test. However, for those with higher WMC, the interaction of cortisol level and math anxiety was critical. For those unafraid of math, the more their cortisol increased during the test, the better they performed; but for those anxious about math, rising cortisol meant poorer performance.

It’s assumed that low-WMC individuals were less affected because their performance is lower to start with (this shouldn’t be taken as an inevitability! Low-WMC students are disadvantaged in a domain like math, but they can learn strategies that compensate for that problem). But the effect on high-WMC students demonstrates how our attitude and beliefs interact with the effects of stress. We may all have the same physiological responses, but we interpret them in different ways, and this interpretation is crucial when it comes to ‘higher-order’ cognitive functions.

Another study investigated two theories as why people choke under pressure: (a) they’re distracted by worries about the situation, which clog up their working memory; (b) the stress makes them pay too much attention to their performance and become self-conscious. Both theories have research backing from different domains — clearly the former theory applies more to the academic testing environment, and the latter to situations involving procedural skill, where explicit attention to the process can disrupt motor sequences that are largely automatic.

But it’s not as simple as one effect applying to the cognitive domain, and one to the domain of motor skills, and it’s a little mysterious why pressure could have too such opposite effects (drawing attention away, or toward). This new study carried out four experiments in order to define more precisely the characteristics of the environment that lead to these different effects, and suggest solutions to the problem.

In the first experiment, participants were given a category learning task, in which some categories had only one relevant dimension and could be distinguished according to one easily articulated rule, and others involved three relevant dimensions and one irrelevant one. Categorization in this case was based on a complex rule that would be difficult to verbalize, and so participants were expected to integrate the information unconsciously.

Rule-based category learning was significantly worse when participants were also engaged in a secondary task requiring them to monitor briefly appearing letters. However it was not affected when their secondary task involved them explicitly monitoring the categorization task and making a confidence judgment. On the other hand, the implicit category learning task was not disrupted by the letter-monitoring task, but was impaired by the confidence-judgment task. Further analysis revealed that participants who had to do the confidence-judgment task were less likely to use the best strategy, but instead persisted in trying to verbalize a one- or two-dimension rule.

In the second experiment, the same tasks were learned in a low-pressure baseline condition followed by either a low-pressure control condition or one of two high-pressure conditions. One of these revolved around outcome — participants would receive money for achieving a certain level of improvement in their performance. The other put pressure on the participants through monitoring — they were watched and videotaped, and told their performance would be viewed by other students and researchers.

Rule-based category learning was slower when the pressure came from outcomes, but not when the pressure came from monitoring. Implicit category learning was unaffected by outcome pressure, but worsened by monitoring pressure.

Both high-pressure groups reported the same levels of pressure.

Experiment 3 focused on the detrimental combinations — rule-based learning under outcome pressure; implicit learning under monitoring pressure — and added the secondary tasks from the first experiment.

As predicted, rule-based categories were learned more slowly during conditions of both outcome pressure and the distracting letter-monitoring task, but when the secondary task was confidence-judgment, the negative effect of outcome pressure was counteracted and no impairment occurred. Similarly, implicit category learning was slowed when both monitoring pressure and the confidence-judgment distraction were applied, but was unaffected when monitoring pressure was counterbalanced by the letter task.

The final experiment extended the finding of the second experiment to another domain — procedural learning. As expected, the motor task was significantly affected by monitoring pressure, but not by outcome pressure.

These findings suggest two different strategies for dealing with choking, depending on the situation and the task. In the case of test-taking, good test preparation and a writing exercise can boost performance by reducing anxiety and freeing up working memory. If you're worried about doing well in a game or giving a memorized speech in front of others, you instead want to distract yourself so you don't become focused on the details of what you're doing.

A large study has found studying scientific text by practicing retrieval produced greater long-term recall than studying by elaborating the information in concept maps.

I’ve talked about the importance of retrieval practice at length, so I’m pleased to report on the latest study to confirm its value. Indeed, this study demonstrates that practicing retrieval is a more effective strategy than elaborative studying.

In two studies, a total of 200 students studied texts on topics from different science disciplines. One group engaged in elaborative studying by creating concept maps. The second group read the texts, then put the material away and practiced recalling the concepts from the text. Both groups performed at about the same level on a test at the end of the study period. However, when the students were tested again a week later, the group that studied by practicing retrieval performed 50% better than the group that studied by creating concept maps.

The test involved understanding as well as memory, with some of the questions asking them to draw connections between things that weren't explicitly stated in the material.

The study also confirms that most students are poor at judging the success of their study habits. Asked to predict which technique would produce better results, most thought that concept mapping would be superior.

The findings should certainly not be taken as a slur on concept mapping, which is a study strategy of proven effectiveness. Moreover, while concept mapping can be used solely as an elaborative study method (as it was in these experiments), it can also be used as a retrieval practice technique.

New research has come up with a very easy remedy for those who sabotage themselves in exams by being over-anxious — spend a little time writing out your worries just before the test.

It’s well known that being too anxious about an exam can make you perform worse, and studies indicate that part of the reason for this is that your limited working memory is being clogged up with thoughts related to this anxiety. However for those who suffer from test anxiety, it’s not so easy to simply ‘relax’ and clear their heads. But now a new study has found that simply spending 10 minutes before the exam writing about your thoughts and feelings can free up brainpower previously occupied by testing worries.

In the first laboratory experiments, 20 college students were given two math tests. After the first test, the students were told that there would be a monetary reward for high marks — from both them and the student they had been paired with. They were then told that the other student had already sat the second test and improved their score, increasing the pressure. They were also they’d be videotaped, and their performance analyzed by teachers and students. Having thus upped the stakes considerably, half the students were given 10 minutes to write down any concerns they had about the test, while the other half were just given 10 minutes to sit quietly.

Under this pressure, the students who sat quietly did 12% worse on the second test. However those who wrote about their fears improved by 5%. In a subsequent experiment, those who wrote about an unrelated unemotional event did as badly as the control students (a drop of 7% this time, vs a 4% gain for the expressive writing group). In other words, it’s not enough to simply write, you need to be expressing your worries.

Moving out of the laboratory, the researchers then replayed their experiment in a 9th-grade classroom, in two studies involving 51 and 55 students sitting a biology exam. The students were scored for test anxiety six weeks before the exam. The control students were told to write about a topic that wouldn’t be covered in the exam (this being a common topic in one’s thoughts prior to an exam). It was found that those who scored high in test anxiety performed poorly in the control condition, but at the level of those low in test anxiety when in the expressive writing condition (improving their own performance by nearly a grade point). Those who were low in test anxiety performed at the same level regardless of what they wrote about prior to the exam.

One of the researchers, Sian Beilock, recently published a book on these matters: Choke: What the Secrets of the Brain Reveal About Getting It Right When You Have To

Why does testing improve memory? A new study suggests one reason is that testing supports the use of more effective encoding strategies.

In an experiment to investigate why testing might improve learning, 118 students were given 48 English-Swahili translation pairs. An initial study trialwas followed by three blocks of practice trials. For one group, the practice trial involved a cued recall test followed by restudy. For the other group, they weren’t tested, but were simply presented with the information again (restudy-only). On both study and restudy trials, participants created keywords to help them remember the association. Presumably the 48 word pairs were chosen to make this relatively easy (the example given in the paper is the easy one of wingu-cloud). A final test was given one week later. In this final test, participants received either the cue only (e.g. wingu), or the cue plus keyword, or the cue plus a prompt to remember their keyword.

The group that were tested on their practice trials performed almost three times better on the final test compared to those given restudy only (providing more evidence for the thesis that testing improves learning). Supporting the hypothesis that this has to do with having more effective keywords, keywords were remembered on the cue+prompt trials more often for the test-restudy group than the restudy-only group (51% vs 34%). Moreover, providing the keywords on the final test significantly improved recall for the restudy-only group, but not the test-restudy group (the implication being that they didn’t need the help of having the keywords provided).

The researchers suggest that practice tests lead learners to develop better keywords, both by increasing the strength of the keywords and by encouraging people to change keywords that aren’t working well.

[1929] Pyc, M. A., & Rawson K. A. (2010).  Why Testing Improves Memory: Mediator Effectiveness Hypothesis. Science. 330(6002), 335 - 335.

In another demonstration of the many factors that affect exam success, three experiments have found that seeing the letter A before an exam makes a student more likely to perform better than if he sees the letter F instead.

In another demonstration of the many factors that affect exam success, three experiments involving a total of 131 college students have found that seeing the letter A before an exam makes a student more likely to perform better than if he sees the letter F instead. In the first experiment, 23 undergraduates took a word-analogies test, of which half were labeled "Test Bank ID: F" in the top right corner, and half "Test Bank ID: A". The A group got an average of 11.08 of 12 answers correct, compared to 9.42 for the F group. The same pattern was confirmed in two more studies. Moreover, performance of students whose exams were labeled "Test Bank ID:J" fell between those with the A and F test papers. While hard to believe, these findings are consistent with the many findings supporting the idea of "stereotype threat" (the tendency to do less well on a test when a person fears their performance could confirm a negative stereotype about their racial or gender group).

[154] Ciani, K. D. [1], & Sheldon K. M. [2] (2010).  A versus F: The effects of implicit letter priming on cognitive performance. British Journal of Educational Psychology. 80, 99 - 119.

Spacing effect

Many of the reports on testing also relate to the spacing effect. To prevent duplication, the reports below exclude reports that appear above, even if they relate to the spacing effect.

Latest news

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 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 for more on this.)

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

New mouse research helps explain why the spacing effect occurs.

I’ve spoken often about the spacing effect — that it’s better to spread out your learning than have it all massed in a block. A study in which mice were trained on an eye movement task (the task allowed precise measurement of learning in the brain) compared learning durability after massed training or training spread over various spaced intervals (2.5 hours to 8 days, with 30 minute to one day intervals). In the case of massed training, the learning achieved at the end of training disappeared within 24 hours. However learning gained in spaced training did not.

Moreover, when a region in the cerebellum connected to motor nuclei involved in eye movement (the flocculus) was anesthetized, the learning achieved from one hour of massed training was eliminated, while learning achieved from an hour of training spaced out over four hours was unaffected. This suggests that the memories had been transferred out of the flocculus (to the vestibular nuclei) within four hours.

However, when protein synthesis in the flocculus was blocked, learning from spaced training was impaired, while learning from massed training was not. This suggests that proteins synthesized in the flocculus play a vital part in the transfer to the vestibular nuclei.

A new way of analyzing brain activity has revealed that memories are stronger when the pattern of brain activity is more closely matched on each repetition.

An intriguing new study has found that people are more likely to remember specific information if the pattern of activity in their brain is similar each time they study that information. The findings are said to challenge the long-held belief that people retain information more effectively when they study it several times under different contexts, thus giving their brains multiple cues to remember it. However, although I believe this finding adds to our understanding of how to study effectively, I don’t think it challenges the multiple-context evidence.

The finding was possible because of a new approach to studying brain activity, which was used in three experiments involving students at Beijing Normal University. In the first, 24 participants were shown 120 faces, each one shown four times, at variable intervals between the repetitions. They were tested on their recognition (using a set of 240 faces), and how confident they were in their decision, one hour later. Subsequent voxel-by-voxel analysis of 20 brain regions revealed that the similarity of the patterns of brain activity in nine of those regions for each repetition of a specific face was significantly associated with recognition.

In the second experiment, 22 participants carried out a semantic judgment task on 180 familiar words (deciding whether they were concrete or abstract). Each word was repeated three times, again at variable intervals. The participants were tested on their recall of the words six hours later, and then tested for recognition. Fifteen brain regions showed a higher level of pattern similarity across repetitions for recalled items, but not for forgotten items.

In the third experiment, 22 participants performed a different semantic judgment task (living vs non-living) on 60 words. To prevent further encoding, they were also required to perform a visual orientation judgment task for 8 seconds after each semantic judgment. They were given a recall test 30 minutes after the session. Seven of the brain regions showed a significantly higher level of pattern similarity for recalled items.

It's interesting to observe how differences in the pattern of activity occurred when studying the same information only minutes apart — a difference that is presumed to be triggered by context (anything from the previous item to environmental stimuli or passing thoughts). Why do I suggest that this finding, which emphasizes the importance of same-context, doesn’t challenge the evidence for multiple-context? I think it’s an issue of scope.

The finding shows us two important things: that context changes constantly; that repetition is made stronger the closer context is matched. Nevertheless, this study doesn’t bear on the question of long-term recall. The argument has never been that multiple contexts make a memory trace stronger; it has been that it provides more paths to recall — something that becomes of increasing importance the longer the time between encoding and recall.

New research confirms that it’s better to practice more than one skill at a time than to engage in repetitive drills of the same action, and reveals that different brain regions are involved in these two scenarios.

A new study explains why variable practice improves your memory of most skills better than practice focused on a single task. The study compared skill learning between those asked to practice one particular challenging arm movement, and those who practiced the movement with other related tasks in a variable practice structure. Using magnetic stimulation applied to different parts of the brain after training (which interferes with memory consolidation), it was found that interference to the dorsolateral prefrontal cortex, but not to the primary motor cortex, affected skill learning for those engaged in variable practice, whereas interference to the motor cortex, but not to the prefrontal cortex, affected learning in those engaged in constant practice.

These findings indicate that variable practice involves working memory (which happens in the prefrontal cortex) rather than motor memory, and that the need to re-engage with the task each time underlies the better learning produced by variable practice (which involves repeatedly switching between tasks). The experiment also helps set a time frame for this consolidation — interference four hours after training had no effect.

A study using two training programs to help dementia patients regain eating skills, found spaced retrieval training was particularly effective.

Loss of memory and problems with judgment in dementia patients can cause difficulties in relation to eating and nutrition; these problems in turn can lead to poor quality of life, pressure ulcers and infections. A study used two different step-by-step training programs to help dementia patients regain eating skills. Three institutions, involving 85 patients, were assigned to one of three programs: spaced retrieval training; Montessori-based training; control. Training consisted of three 30-40 min sessions per week, for 8 weeks. Both training programs resulted in significantly improved feeding skills, however the Montessori group needed more physical and verbal assistance. Nutritional status was significantly higher in the spaced-retrieval group compared to the control.

Lin, L., Huang, Y., Su, S., Watson, R., Tsai, B. W., & Wu, S. (2010). Using spaced retrieval and Montessori-based activities in improving eating ability for residents with dementia. International Journal of Geriatric Psychiatry, 9999(9999), n/a. doi: 10.1002/gps.2433.

Older news items (pre-2010) brought over from the old website

The importance of retrieval cues

An imaging study has revealed that it is retrieval cues that trigger activity in the hippocampus, rather than, as often argued, the strength of the memory. The study involved participants learning unrelated word pairs (a process which included making up sentences with the words), then being asked whether various familiar words had been previously seen or not — the words being shown first on their own, and then with their paired cue word. Brain activity for words judged familiar on their own was compared with activity for the same items when shown with context cues. Increased hippocampal activity occurred only with cued recall. Moreover, the amount of activity was not associated with familiarity strength, and recollected items were associated with greater activity relative to highly familiar items.
[1102] Cohn, M., Moscovitch M., Lahat A., & McAndrews M. P. (2009).  Recollection versus strength as the primary determinant of hippocampal engagement at retrieval. Proceedings of the National Academy of Sciences. 106(52), 22451 - 22455.
http://www.eurekalert.org/pub_releases/2009-12/uot-dik120709.php

Making student self-testing an effective study tool

A series of four experiments with 150 college students using Swahili-English vocabulary words has revealed that repeated retrieval was a very effective learning strategy. However, when subjects were given control over their own learning, they did not attempt retrieval as early or as often as they should to promote the best learning. The findings are thought to reflect a powerful metacognitive illusion that occurs during self-regulated learning — namely, that easy retrieval tends to make students believe they have “learned” it before the material is properly mastered, leading to premature termination of the study practice.
[285] Karpicke, J. D. (2009).  Metacognitive Control and Strategy Selection: Deciding to Practice Retrieval During Learning. Journal of Experimental Psychology: General. 138(4), 469 - 486.
http://www.eurekalert.org/pub_releases/2009-12/pu-sse121009.php

Longer high-stakes tests may result in a sense of mental fatigue, but not in lower test scores

A study involving 239 freshman college students who took three different versions of the SAT Reasoning Test, of progressively longer lengths (3.5, 4.5, 5.5 hours), has revealed that although the students reported higher levels of mental fatigue with longer tests, performance was not affected. In fact, the average performance for both the standard and long tests was significantly higher than for the short test. Moreover, the fatigue experienced was less related to the length of the exam (and to the amount of sleep they’d had) than it was to personality traits. Those with higher levels of achievement motivation and competitiveness felt less fatigue, and those with higher levels of neuroticism and anxiety felt more.
[1127] Ackerman, P. L., & Kanfer R. (2009).  Test length and cognitive fatigue: an empirical examination of effects on performance and test-taker reactions. Journal of Experimental Psychology. Applied. 15(2), 163 - 181.
Full text available at http://www.apa.org/journals/releases/xap152-ackerman-kanfer.pdf
http://www.eurekalert.org/pub_releases/2009-06/apa-lht052809.php

Why we don't always learn from our mistakes

A study of the tip-of-the-tongue (TOT) phenomenon suggests that most errors are repeated because the very act of making a mistake, despite receiving correction, constitutes the learning of that mistake. The study asked students to retrieve words after being given a definition. If that produced a TOT state, they were randomly assigned to spend either 10 or 30 seconds trying to retrieve the answer before finally being shown it. When tested two days later, it was found that they tended to TOT on the same words as before, and were especially more likely to do so if they had spent a longer time trying to retrieve them The longer time in the error state appears to reinforce that incorrect pattern of brain activation that caused the error.
[225] Warriner, A. B., & Humphreys K. R. (2008).  Learning to fail: reoccurring tip-of-the-tongue states. Quarterly Journal of Experimental Psychology (2006). 61(4), 535 - 542.
http://www.physorg.com/news126265455.html

Testing strengthens recall whether something's on the test or not

The simple act of taking a test appears to help you remember everything you learned, even if it isn't tested. In a series of three experiments, researchers found undergraduates tested after being given 25 minutes to study a long article about the toucan bird recalled more a day later than those given further information about the toucan in an extra study session, or those who had neither experience. In the second experiment, students were given two articles to read, one of which was tested and one of which was not. Again, the one tested was remembered significantly better a day later. The third experiment revealed that later recall was better the more time the student had spent on answering questions in the first test. This relation was especially pronounced for students with lower performance on the test, and those who were encouraged to guess did significantly better on the second test than students who were discouraged from guessing.
[1188] Chan, J. C. K., McDermott III K. B., & Roediger H. L. (2006).  Retrieval-Induced Facilitation: Initially Nontested Material Can Benefit From Prior Testing of Related Material. Journal of Experimental Psychology: General. 135(4), 553 - 571.
http://www.eurekalert.org/pub_releases/2006-11/apa-tsr110606.php

Repeated test-taking better for retention than repeated studying

A study indicates that testing can be a powerful means for improving learning, not just assessing it. The study compared students who studied a prose passage for about five minutes and then took either one or three immediate free-recall tests, receiving no feedback on the accuracy of answers, with students who received no tests, but were allowed another five minutes to restudy the passage each time their counterparts were involved in a testing session. While the study-only group performed better on the test after the last session, they performed worse when tested 2 days later, and dramatically worse after one week. Note that the study-only group had read the passage about 14 times in total, while the repeated testing group had read the passage only 3.4 times in its one-and-only study session. It also appears that students who rely on repeated study alone often come away with a false sense of confidence about their mastery of the material.
[272] Roediger, H. L., & Karpicke J. D. (2006).  Test-enhanced learning: taking memory tests improves long-term retention. Psychological Science: A Journal of the American Psychological Society / APS. 17(3), 249 - 255.
http://www.eurekalert.org/pub_releases/2006-03/wuis-rtb030606.php

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