Category: Memory

Pop quiz! Tests are good for: (a) Assessing what you've learned; (b) Learning new information; (c) a & b; (d) None of the above.

The correct answer?

According to research from psychological science, it's both (a) and (b) — while testing can be useful as an assessment tool, the actual process of taking a test can also help us to learn and retain new information over the long term and apply it across different contexts.

New research published in journals of the Association for Psychological Science explores the nuanced interactions between testing, memory, and learning and suggests possible applications for testing in educational settings.

Appropriate Multiple-Choice Tests Can Foster Test-Induced Learning

One of the criticisms of multiple-choice tests is that they expose test takers to the correct answer among the available options. This means that you only have to recognize the correct answer, you don't have to rely on retrieval processes that are known to enhance later recall. Psychological scientist Jeri Little and her colleagues investigated whether multiple-choice tests could actually be designed to call upon these retrieval processes. If the alternative answers are all plausible enough, they hypothesized, test takers would have to retrieve information about why correct alternatives are correct and also about why incorrect alternatives are incorrect in order to be able to distinguish between the two. In two experiments, the researchers found that properly constructed multiple-choice tests can, in fact, trigger productive retrieval processes. They also found that multiple-choice tests had one potentially important advantage over tests in which only the question is presented. Both kinds of tests helped test takers remember the information they been tested on, but only the multiple-choice tests helped them recall information related to incorrect alternatives. These findings suggest that multiple-choice tests can be constructed in ways that exercise the very retrieval processes they have been accused of bypassing.

Jeri L. Little of Washington University in St. Louis was one of the authors. Published online October 3, 2012 in Psychological Science.

Testing Enhances the Transfer of Learning

Many studies have shown that having to retrieve information during a test helps you remember that information later on. But most research on this "testing effect" has measured the ability to recall information in the form of a final test that's similar to the initial test. Much less is known about the whether testing might also promote the application — or transfer — of learning. In this article, psychological scientist Shana Carpenter reviews recent studies that have begun to address this issue, especially as it relates to the benefits of testing on our ability to transfer information across multiple contexts, test formats, and knowledge domains. The few studies on this topic have, so far, reported robust benefits of testing on the transfer of learning. Carpenter highlights the need for research that explores the potential of tests to promote not just the direct retention of information, but also the application of knowledge to new situations.

Shana K. Carpenter of Iowa State University was one of the authors. Published in the October 2012 issue of Current Directions in Psychological Science.

Testing Can Strengthen Short-Term Memory for Cross-Language Information

Researchers know that repeated testing leads to better long-term memory for information than does repeated study, but they're unsure of why this is the case. Psychological scientist Peter Verkoeijen and his colleagues hypothesized that studying may strengthen the aspects of a memory trace that pertain to the way words look and sound, while testing may strengthen the aspects of a memory trace that have to do with the meaning of words. The researchers had Dutch-English bilingual participants learn several lists of words in Dutch. In some instances they were tested after an initial study period (test condition), and in others they were told to study the list again (restudy condition). Participants' memory for the words was then tested in Dutch or English. The main finding shows that participants in the test condition were better at recognizing the words they had been told to learn when they took the final test in English (across-language) but not when they took the final test in Dutch (within-language). These results suggests that using a test as a method of learning — strengthening the meaning of words — was useful for the participants when they weren't able to rely on the visual or phonological familiarity of words because the words were presented in different languages. The results lend support to the researchers' hypothesis that restudying and testing strengthen memory in different ways.

Peter Verkoeijen of Erasmus University Rotterdam was among the authors. Published in the June 2012 issue of Psychological Science.

Active Retrieval Promotes Meaningful Learning

When researchers think about the retrieval of information from memory, they often focus on retrieval as a way to figure out what people have already learned. But psychological scientist Jeffrey Karpicke argues that retrieval processes play a central role in the active process of learning as it happens. Karpicke outlines the retrieval-based learning perspective and discusses the role of retrieval in learning, the means by which it can enhance learning over the long-term, and the ways in which it can help to promote meaningful learning.

Jeffrey D. Karpicke of Purdue University published the article in the June 2012 issue of Current Directions in Psychological Science.

— It happens innocently enough: One minute you're sitting at your desk, working on a report, and the next minute you're thinking about how you probably need to do laundry and that you want to try the new restaurant down the street. Mind wandering is a frequent and common occurrence. And while mind wandering in certain situations — in class, for example — can be counterproductive, some research suggests that mind wandering isn't necessarily a bad thing.

 

New research published in the journals of the Association for Psychological Science explores mind wandering in various contexts, examining how mind wandering is related to cognitive processes involved in working memory and executive control.

Inspired by Distraction: Mind Wandering Facilitates Creative Incubation

Benjamin Baird, Jonathan Smallwood, Michael D. Mrazek, Julia W. Y. Kam, Michael S. Franklin, and Jonathan W. Schooler

You might be driving home from work, taking a shower, preparing ingredients for dinner and, suddenly — "Eureka!" — you have a new insight into some problem or situation. Anecdotes tell us that people often have these kinds of creative thoughts while engaged in unrelated tasks, but researcher Benjamin Baird and colleagues wanted to subject the phenomenon to scientific scrutiny. The researchers designed an experiment in which they asked participants to perform an Unusual Use Task (UUT), listing as many unusual uses for an item as possible. The participants were then split into four groups — one group was asked to perform a demanding task and a second was asked to perform an undemanding task. The third group rested for 12 minutes and a fourth group was given no break. All participants then performed the Unusual Use Task again. Of the four groups, only the people who performed the undemanding task improved their score on the second UUT test. Participants in the undemanding task reported greater instances of mind wandering during the task, which suggests that simple tasks that allow the mind to wander may increase creative problem solving.

Published online August 31, 2012 in Psychological Science

What Mind Wandering Reveals About Executive-Control Abilities and Failures

Michael J. Kane and Jennifer C. McVay

While mind wandering might lead to creative insights, involuntary mind wandering can also take us away from the important activities and tasks at hand. In this article, Kane and McVay discuss the relationships among working memory, task-unrelated thoughts, and task performance. Using both laboratory-based and daily-life assessments, research has shown that people with lower working memory capacity are more likely to mind wander, at least during demanding tasks. This propensity to mind wandering may partly explain why people with lower working memory capacity are also more likely to make errors. Kane and McVay argue that involuntary mind wandering can provide psychological scientists with a unique window into aspects of the mind's mechanisms for cognitive control, including how, when, and for whom these mechanisms fail.

Published in the October 2012 issue of Current Directions in Psychological Science

The Persistence of Thought: Working Memory May Help to Maintain Task-Unrelated Thinking

Daniel B. Levinson, Jonathan Smallwood, and Richard J. Davidson

Our working memory acts as a sort of mental workspace that allows us to juggle multiple thoughts simultaneously, but what role does it play in mind wandering? Does working memory inhibit or support off-task thinking? Psychological scientist Daniel Levinson and colleagues decided to put this issue to the test. They asked volunteers to perform one of two simple tasks — either pressing a button in response to the appearance of a certain letter on a screen, or simply tapping in time with one's breath — and compared people's propensity to drift off. In both tasks, people with higher working memory capacity reported more mind wandering during the tasks, even though their performance on the test wasn't compromised. But when the volunteers were given a comparably simple task that was filled with sensory distractors, the relationship between working memory and mind wandering disappeared. These results suggest that working memory may ultimately reflect underlying priorities, enabling off-topic thoughts when we don't have many other things to keep in mind.

Published in the April 2012 issue of Psychological Science

Rest Is Not Idleness: Implications of the Brain's Default Mode for Human Development and Education

Mary Helen Immordino-Yang, Joanna A. Christodoulou, and Vanessa Singh

While moments for reflection may be hard to come by, some research suggests that the long-lost art of introspection — from mind wandering to focused reflection — may be an increasingly valuable part of life. In this article, psychological scientist Mary Helen Immordino-Yang and colleagues survey the existing scientific literature from neuroscience and psychological science, exploring what it means when our brains are 'at rest.' Immordino-Yang and her colleagues believe that research on the brain at rest can yield important insights into the importance of reflection and quiet time for learning.

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Journal References:

1. B. Baird, J. Smallwood, M. D. Mrazek, J. W. Y. Kam, M. S. Franklin, J. W. Schooler. Inspired by Distraction: Mind Wandering Facilitates Creative Incubation. Psychological Science, 2012; DOI: 10.1177/0956797612446024
2. M. J. Kane, J. C. McVay. What Mind Wandering Reveals About Executive-Control Abilities and Failures. Current Directions in Psychological Science, 2012; 21 (5): 348 DOI: 10.1177/0963721412454875
3. D. B. Levinson, J. Smallwood, R. J. Davidson. The Persistence of Thought: Evidence for a Role of Working Memory in the Maintenance of Task-Unrelated Thinking. Psychological Science, 2012; 23 (4): 375 DOI: 10.1177/0956797611431465
4. M. H. Immordino-Yang, J. A. Christodoulou, V. Singh. Rest Is Not Idleness: Implications of the Brain's Default Mode for Human Development and Education. Perspectives on Psychological Science, 2012; 7 (4): 352 DOI: 10.1177/1745691612447308

— Taking academic tests can be a stressful time for some young people and especially for those with a history of elevated anxiety. However a study published today (12 October 2012) in the British Journal of Psychology shows that anxiety only has a negative effect on test results if memory is also poor.. Furthermore if memory is good, increased anxiety is associated with attaining better marks.

In this study 96 school students aged between 12 and 14, from several schools, completed measures of anxiety and working memory, using computer tests. Good working memory predicts educational attainment. The students were then tested for cognitive ability and maths performance.

It was found that when working memory was poor, increased anxiety was associated with low test scores. When working memory was good, anxiety was associated with higher test results.

Dr Matthew Owens, a researcher at the University of Cambridge (who carried out the study while at the University of Southampton) said: "The research is exciting because it enhances our knowledge of when, specifically, anxiety can have a negative impact on taking tests. The findings also suggest that there are times when a little bit of anxiety can actually motivate you to succeed."

The researchers hope that their project will lead to more understanding of the impact of elevated anxiety on academic testing in young people. Given that anywhere between 10 per cent and 40 per cent* of children are affected by anxiety around taking tests, support offered in schools could be targeted in the first instance to those who are at highest risking of poor outcomes.

The study was funded by the Economic and Social Research Council (ESRC) and Action Medical Research.

— Have you ever wondered why you can remember things from long ago as if they happened yesterday, yet sometimes can't recall what you ate for dinner last night? According to a new study led by psychologists at the University of Toronto, it's because how much something means to you actually influences how you see it as well as how vividly you can recall it later.

"We've discovered that we see things that are emotionally arousing with greater clarity than those that are more mundane," says Rebecca Todd, a postdoctoral fellow in U of T's Department of Psychology and lead author of the study published recently in the Journal of Neuroscience. "Whether they're positive — for example, a first kiss, the birth of a child, winning an award — or negative, such as traumatic events, breakups, or a painful and humiliating childhood moment that we all carry with us, the effect is the same."

"What's more, we found that how vividly we perceive something in the first place predicts how vividly we will remember it later on," says Todd. "We call this 'emotionally enhanced vividness' and it is like the flash of a flashbub that illuminates an event as it's captured for memory."

By studying brain activity, Todd, psychology professor Adam Anderson and other colleagues at U of T, along with researchers at the University of Manchester and the University of California, San Diego found that the part of the brain responsible for tagging the emotional or motivational importance of things according to one's own past experience — the amygdala — is more active when looking at images that are rated as vivid. This increased activation in turn influences activity in both the visual cortex, enhancing activity linked to seeing objects, and in the posterior insula, a region that integrates sensations from the body.

"The experience of more vivid perception of emotionally important images seems to come from a combination of enhanced seeing and gut feeling driven by amygdala calculations of how emotionally arousing an event is," says Todd.

The researchers began by measuring the subjective experience of the vividness of perception. Taking pictures of scenes that were emotionally arousing and negative (scenes of violence or mutilation, or sharks and snakes baring their teeth), emotionally arousing and positive (mostly mild erotica), and neutral scenes (such as people on an escalator), they overlaid the images with varying amounts of "visual noise," which looked like the snow one would see on an old television screen. The pictures were then shown to study participants who were asked to say whether each image had the same, more, or less noise than a standard image with a fixed amount of noise.

"We found that while people were good at rating how much noise was on the picture relative to a standard, they consistently rated pictures that were emotionally arousing as less noisy than neutral pictures regardless of the actual level of noise," says Todd. "When a picture was rated as less noisy, then they actually saw the picture underneath more clearly, as if there is more signal relative to noise in the emotionally arousing picture. The subjective meaning of a picture actually influenced how clearly the participants saw it."

The researchers used additional tests to rule out other explanations of their findings, such as how 'noisy' a picture seems due to less vibrant colours or a more complex scene. They also used eye-tracking measures to eliminate the possibility that people look at emotionally arousing images differently, causing them to rate some as more vivid.

"We next wanted to see if this finding of emotionally enhanced vividness influenced memory vividness," says Todd. "So, in two different studies, we measured memory for the images, both right after seeing them in the first place and one week later."

In the first study, 45 minutes after they did the noise task, participants were asked to write down all the details they could about pictures they remembered seeing. How much detail they remembered was a measure of vividness. In the second study, participants were shown the pictures again one week later and asked if they remembered them and, if so, how vividly they remembered them from very vague to very detailed.

"Both studies found that pictures that were rated higher in emotionally enhanced vividness were remembered more vividly," says Todd.

Finally, the researchers used brain imaging measures to look at when the brain responded to emotionally enhanced vividness and what regions of the brain responded. Using electrophysiology (EEG) to measure the timing of activity in the cortex to see when the brain is sensitive to vividness, gave them a sense of whether this subjective vividness was more about seeing vividly, or thinking that it was more vivid when you're considering it after the fact.

"We found that the brain indexes vividness pretty quickly — about a 5th of a second after seeing a picture, which suggests it's about seeing and not just thinking," says Todd. "Emotion alters activity in the visual cortex, which in turn influences how we see."

The investigators also used functional magnetic resonance imaging (fMRI) to look at what brain regions were more active when people look at things that they perceive as more vivid because they're emotionally important. Again, they found amygdala, visual cortex, and interoceptive cortex activity went up with increased vividness.

"We know now why people perceive emotional events so vividly — and thus how vividly they will remember them — and what regions of the brain are involved," says Todd. "Knowing that there are going to be differences among people as to how strongly they show this emotionally enhanced vividness and the strength of the brain activation patterns underlying them, could be useful in predicting an individual's vulnerability to trauma, including intrusive memories experienced by people with post-traumatic stress disorder."

Funding for the research was provided by the U.S. National Institute for Mental Health and the Canadian Institutes of Health Research.

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Journal Reference:

1. Rebecca M. Todd, Deborah Talmi, Taylor W. Schmitz, Josh Susskind, and Adam K. Anderson. Psychophysical and Neural Evidence for Emotion-Enhanced Perceptual Vividness. Journal of Neuroscience, 2012 DOI: 10.1523/%u200BJNEUROSCI.0155-12.2012

— Research has found that declines in temporal information processing (TIP), the rate at which auditory information is processed, underlies the progressive loss of function across multiple cognitive systems in the elderly, including new learning, memory, perception, attention, thinking, motor control, problem solving, and concept formation. In a new study, scientists have found that elderly subjects who underwent temporal training improved not only the rate at which they processed auditory information, but also in other cognitive areas. The study is published in the current issue of Restorative Neurology and Neuroscience.

"Our study showed for the first time significant benefits of temporal training on broad aspects of cognitive function in the elderly. The results were long-lasting, with effects confirmed 18 months after the training," says lead investigator Elzbieta Szelag, Professor, Head of Laboratory of Neuropsychology, Nencki Institute of Experimental Biology, and Warsaw School of Social Sciences and Humanities (www.swps.pl), Warsaw, Poland.

Thirty subjects between 65 and 75 years of age were randomly assigned to three groups. One group received temporal training using Fast ForWord Language^® (FFW), a program composed of several computer games designed to improve memory, attention, and sequencing abilities. The program was developed to help children who have trouble reading, writing, and learning. The second group participated in non-temporal training by playing common computer games. The third group, the control, underwent no training.

Prior to the training, all of the subjects went through a number of tests to measure their cognitive functioning. Two tasks assessed TIP by measuring sequencing abilities. Specifically, at which inter-stimulus-interval subjects could identify the order of two stimuli presented in rapid sequence, i.e. which of two tones was higher or lower, or whether they heard a sound in the right or left ear first. Three aspects of attention were assessed: the ability to sustain attention over a longer period of time (vigilance), the ability to pay attention to multiple processes (divided attention), and the ability to maintain a high level of attention in anticipation of a test stimulus (alertness). Short-term memory was assessed with tests to evaluate working memory span, the ability to match complex patterns, and the ability to recognize a pattern seen earlier.

Each subject in the temporal training group started with exercises from the basic module of FFW. When they reached 100% complete for each exercise, they moved onto an intermediate program, and then an advanced program. They trained for an hour a day, four days a week, for eight weeks. The non-temporal training group played computer games such as Solitaire or Internet games such as Mahjong for the same amount of time. The control group received no training but was tested before and after the eight-week period.

At the end of the training period, cognitive functioning was re-assessed. Prior to training, no significant differences were found among the three groups. After the training, improved temporal information processing was found on the tone task in the temporal training group. It was accompanied by improvements in some aspects of attention and short-term memory. In contrast, the non-temporal training group's attentional and memory resources scores remained at the pre-training level, while only the second measure of temporal information processing improved. Changes in the control group were nonsignificant.

The temporal training group was tested again 18 months after the training completion. The positive effects remained stable. TIP, divided attention, matching complex patterns, and working memory span remained at a similar level as in the post-training assessment. Although vigilance of attention declined from the post-training assessment, for all measures the results were not worse than in the pre-training assessment. "Although FFW does not train other cognitive functions directly, attention and short-term memory resources were necessary to perform the training tasks correctly," explain Professor Szelag and Dr Skolimowska. "To succeed in the FFW games, the temporal skills had to be accompanied by efficient basic cognitive processes."

Professor Szelag concludes, "These results show a new impact of temporal training on age-related cognitive decline in the senior population. Moreover, they foster a greater understanding of the relationships between timing and cognition, and they show new possibilities for the application of temporal training." On the

Working with units of material so small that it would take 50,000 to make up one drop, scientists are developing the profiles of the contents of individual brain cells in a search for the root causes of chronic pain, memory loss and other maladies that affect millions of people.

They described the latest results of this one-by-one exploration of cells or "neurons" from among the millions present in an animal brain at the 244^th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society. The meeting, expected to attract almost 14,000 scientists and others from around the world, continues in Philadelphia through Thursday, with 8,600 presentations on new discoveries in science and other topics.

Jonathan Sweedler, Ph.D., a pioneer in the field, explained in a talk at the meeting that knowledge of the chemistry occurring in individual brain cells would provide the deepest possible insights into the causes of certain diseases and could point toward new ways of diagnosis and treatment. Until recently, however, scientists have not had the technology to perform such neuron-by-neuron research.

"Most of our current knowledge about the brain comes from studies in which scientists have been forced to analyze the contents of multiple nerve cells, and, in effect, average the results," Sweedler said. He is with the University of Illinois at Urbana-Champaign and also serves as editor-in-chief of Analytical Chemistry, which is among ACS' more than 40 peer-reviewed scientific journals. "That approach masks the sometimes-dramatic differences that can exist even between nerve cells that are shoulder-to-shoulder together. Suppose that only a few cells in that population are changing, perhaps as a disease begins to take root or starts to progress or a memory forms and solidifies. Then we would miss those critical changes by averaging the data."

However, scientists have found it difficult to analyze the minute amounts of material inside single brain cells. Those amounts are in the so-called "nanoliter" range, units so small that it would take 355 billion nanoliters to fill a 12-ounce soft-drink can. Sweedler's group spent much of the past decade developing the technology to analyze the chemicals found in individual cells — a huge feat with a potentially big pay-off. "We are using our new approaches to understand what happens in learning and memory in the healthy brain, and we want to better understand how long-lasting, chronic pain develops," he said.

The 85 billion neurons in the brain are highly interconnected, forming an intricate communications network that makes the complexity of the Internet pale in comparison. The neural net's chemical signaling agents and electrical currents orchestrate a person's personality, thoughts, consciousness and memories. These connections are different from person to person and change over the course of a lifetime, depending on one's experiences. Even now, no one fully understands how these processes happen.

To get a handle on these complex workings, Sweedler's team and others have zeroed in on small sections of the central nervous system ― the brain and spinal cord ― using stand-ins for humans such as sea slugs and laboratory rats. Sweedler's new methods enable scientists to actually select areas of the nervous system, spread out the individual neurons onto a glass surface, and one-by-one analyze the proteins and other substances inside each cell.

One major goal is to see how the chemical make-up of nerve cells changes during pain and other disorders. Pain from disease or injuries, for instance, is a huge global challenge, responsible for 40 million medical appointments annually in the United States alone.

Sweedler reported that some of the results are surprising, including tests on cells in an area of the nervous system involved in the sensation of pain. Analysis of the minute amounts of material inside the cells showed that the vast majority of cells undergo no detectable change after a painful event. The chemical imprint of pain occurs in only a few cells. Finding out why could point scientists toward ways of blocking those changes and in doing so, could lead to better ways of treating pain.

 Together with his team, Prof. Christoph Ploner, director of the Department of Neurology at the Virchow campus, examined a professional cellist who suffered from encephalitis caused by a herpes virus. As a result of the inflammation, the patient developed serious disturbances in memory.

Both his memory for the past (retrograde amnesia), as well as the acquisition of new information (anterograde amnesia) were affected. Whereas the patient was unable to recount any events from his private or professional life, or remember any of his friends or relatives, he retained a completely intact musical memory. Furthermore, he was still able to sight-read and play the cello.

For the systematic examination of his musical memory, Dr. Carsten Finke, Nazli Esfahani and Prof. Christoph Ploner developed various tests that take the beginning of his amnesia into account. In comparison to amateur musicians and professional musicians from the Berlin Philharmonic, the patient showed a normal musical memory in all tests. He not only remembered music pieces from the past, but was also able to retain music he had never heard before.

"The findings show that musical memory is organized at least partially independent of the hippocampus, a brain structure that is central to memory formation," says Carsten Finke, the primary author of the study. "It is possible that the enormous significance of music throughout all times and in all cultures contributed to the development of an independent memory for music."

Carsten Finke and his colleagues hope that the intact musical memory in patients with amnesia can be used to stimulate other memory content. In this way, perhaps a particular melody can be connected to a person or an everyday task, for example taking medicine.

It has long been believed that drinking green tea is good for the memory. Now researchers have discovered how the chemical properties of China's favorite drink affect the generation of brain cells, providing benefits for memory and spatial learning.

The research is published in Molecular Nutrition & Food Research.

"Green tea is a popular beverage across the world," said Professor Yun Bai from the Third Military Medical University, Chongqing, China. "There has been plenty of scientific attention on its use in helping prevent cardiovascular diseases, but now there is emerging evidence that its chemical properties may impact cellular mechanisms in the brain."

Professor Bai's team focused on the organic chemical EGCG, (epigallocatechin-3 gallate) a key property of green tea. While EGCG is a known anti-oxidant, the team believed it can also have a beneficial effect against age-related degenerative diseases.

"We proposed that EGCG can improve cognitive function by impacting the generation of neuron cells, a process known as neurogenesis," said Bai. "We focused our research on the hippocampus, the part of the brain which processes information from short-term to long-term memory."

The team found that EGCG boosts the production of neural progenitor cells, which like stem cells can adapt, or differentiate, into various types of cells. The team then used laboratory mice to discover if this increased cell production gave an advantage to memory or spatial learning.

"We ran tests on two groups of mice, one which had imbibed EGCG and a control group," said Bai. "First the mice were trained for three days to find a visible platform in their maze. Then they were trained for seven days to find a hidden platform."

The team found that the EGCG treated mice required less time to find the hidden platform. Overall the results revealed that EGCG enhances learning and memory by improving object recognition and spatial memory.

"We have shown that the organic chemical EGCG acts directly to increase the production of neural progenitor cells, both in glass tests and in mice," concluded Bai. "This helps us to understand the potential for EGCG, and green tea which contains it, to help combat degenerative diseases and memory loss."

This paper is published as part of a collection of articles bringing together high quality research on the theme of food science and technology with particular relevance to China. Browse free articles from Wiley's food science and technology publications including the Journal of Food Science, Journal of the Science of Food and Agriculture and Molecular Nutrition & Food Research.

Standard head movements made while exposed to one of the three electromagnetic fields produced by a heavy duty MRI scanner seem to temporarily lower concentration and visuospatial awareness, shows an experimental study published online in Occupational and Environmental Medicine.

The effects were particularly noticeable in tasks requiring high levels of working memory, which may have implications for surgeons and other healthcare staff working within the vicinity of an MRI scanner, the research indicates.

Magnetic resonance imaging (MRI) uses strong magnetic fields and radio waves to take very detailed pictures of the brain and spine. Three types of electromagnetic fields are required to create an image: static; switched gradient; and radiofrequency.

The static magnetic field is always present, even when no imaging is taking place.

Thirty one volunteers made standard head movements within the static magnetic field of a higher field 7 Tesla MRI scanner at exposure levels of zero (sham), 0.5 (medium), and 1 (high)Tesla, in a random order, one week apart.

After each exposure level, the volunteers were set 12 timed cognitive tasks, designed to test the sorts of skills that a surgeon or other healthcare professional might need to deploy within the vicinity of an MRI scanner.

These included visual tracking and movement, as well as more general functions, such as attention, concentration and working memory. The tests were neutral in that they didn't test intelligence or depend on practice.

In all, 30 volunteers completed all three sessions. Compared with the sham test, the results showed that the more general functions, such as attention and concentration, and visuospatial awareness were significantly affected.

For complex mental tasks, reaction and disengagement times were longer, varying from 5% to 21%, the higher the level of Tesla exposure.

Complex tasks rely on working memory, suggesting that less of this is available to keep the same levels of attention and concentration going at higher levels of exposure, say the authors.

While non-verbal memory did not seem to be affected, there was a fall in verbal memory, although this only reached borderline significance. At the highest level of exposure, volunteers also experienced some physical symptoms, including metallic taste in the mouth (12 people), dizziness (6), headache (5), and nausea (1).

"The exact implications and mechanisms of these subtle acute effects in [practice] remain unclear," write the authors.

But the introduction of increasingly more powerful MRI machines has boosted exposure levels to static electromagnetic fields for both patients and staff, they say.

"To date, mainly health and safety concerns for patients have been evaluated, but possible consequences are particularly important for professionals……cleaners, and MRI engineers since they are repeatedly exposed to static magnetic fields," they add.

When we let our hearts choose for us, we are more influenced by people who resemble ourselves, a PhD study from BI Norwegian Business School shows.

Every day we have to make a number of choices, and it is not always easy to know what the right choice is. That is why we often seek advice from others before making decisions. The Internet provides us with entirely new ways of finding out what other people feel about different products and services.

Many of us book hotel rooms online. Unless we are already familiar with the hotel, we will probably read reviews by former guests at the hotel before making up our minds. Such reviews are written by many different types of guests, families with small children, families with older children, single travellers, older guests and many other groups.

If you are a 25 year old student, for instance, you might attach different weight to a review from a student of your own age (the reviewer is similar to you) than you would to the comments from a 60 year old professor (who is different from you).

Influence from those who are similar

In his PhD study at BI Norwegian Business School, Ali Faraji Rad has conducted seven experiments to see whether we are more easily persuaded by people who are similar to us than by people who are dissimilar to us. He also looked at what circumstance might make the differences greater.

In all the experiments, participants were asked to imagine that they were going to book a hotel room online, and that they were reading a review of the hotel they were considering. Participants were then given a negative review of this hotel, along with a profile of the reviewer. The profiles were designed to create a feeling of similarity or dissimilarity with the participant in the experiment.

"Participants were more influenced by reviewers who were similar to themselves than by reviewers who were dissimilar. This difference was greatest when the choice of hotels was based on emotions and not logic," explains Ali Faraji Rad.

Logic and feelings

In the first experiment, half of the participants were asked to use logic in evaluating the hotel, while the others were was asked to base their evaluation on feelings. Those participants who based their evaluation on feelings, were influenced by reviewers similar to themselves.

Similar reviewers had no influence on participants who chose their hotel room on the basis of common sense and logic.

In the second experiment, half the participants were asked to write down some thoughts on why it is good to use logic when making decisions, while the other half was asked to write about why it is good to use our emotions when making decisions.

In this way, participants were primed to base their choice on logic or emotions.

The second experiment showed the same results as the first one. Participants who used their emotions were influenced, while those who followed their sense of logic were unaffected by reviewers who resembled themselves.

Business or pleasure

In experiments 3 and 4, Ali Faraji Rad instructed half of the participants to imagine that they were going away for fun, while the other half thought they would be travelling with work.

Previous studies have shown that we are more likely to use our emotions when we travel for fun than if we have more functional motives (such as a business trip).

Those participants who were thinking of a trip for fun were, as expected, more affected by the similar reviewer than those who were told to imagine a business trip.

Near and within reach

One half of the participants in the fifth experiment were asked to evaluate the hotel and imagine that they would be travelling next week, while the others were told they would be going in a year's time.

Participants who thought they were going next week were more influenced by similar reviewers than those who were to travel in a year's time. "Our choices are more based on emotions when they concern the near future."

In the sixth experiment, half the participants were told to imagine they were in a lottery where the chance of winning the hotel package was 1 to 5, while the other half received much longer odds, 1 to 5000.

Participants with the best chance of winning were more influenced by the similar reviewer than participants with longer odds.

"With a good chance of winning we feel that the trip is within reach, and we base our choice more on feelings," says Faraji-Rad.

Information in one's memory

In the seventh and final experiment of the PhD study, half the participants had to remember a seven-digit figure while assessing the hotel. The other half only had to remember a two-digit figure.

Earlier research has shown that we are more likely to use our emotions when we have to retain too much information in our memory.

Those participants who had to remember the seven-digit figure were more influenced by the similar reviewer (than by the dissimilar reviewer), even when they envisioned going on a business trip.

Reference:

Ali Faraji-Rad: When the message feels right. Investigating how source similarity enhances message persuasiveness, Series of Dissertation 8/2012. BI Norwegian Business School.