News reports of research into memory August 2007

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August 2007

Cramming doesn't work in the long term

Thinking back on how much you remember from your schooldays, it’s apparent to most of us that despite all the time spent in school, we’ve forgotten most of what we learned. A new study points to what we were doing wrong. The study looked at overlearning, which is the term for continuing to study after you’ve apparently learned it. Students went through a list of new words either five times (getting a perfect score no more than once) or ten times (getting it perfect at least three times). A week later, students who did the extra drilling performed better when tested, but four weeks later there was no difference. The results suggest that overlearning in a single session is wasted effort. However, when the material was studied in two separate sessions, and the break between sessions was at least a month, students did much better. Although the experiments involved rote learning, the researchers have also found similar effects with more abstract learning, like math.
The study was reported in the August issue of Current Directions in Psychological Science. Full reference
http://www.eurekalert.org/pub_releases/2007-08/afps-bts082907.php

Pointers for better learning

One of the crucial aspects to learning efficiently is being able to accurately assess your own learning process. Research has shown that in general people are not very accurate at judging how well they have learned complex materials. A review of recent research into how to improve judgment accuracy has concluded that rereading or summarizing text can help, as well as techniques that focus people’s attention on just the most important details of a text, such as trying to recall the key ideas from memory.
The article was published in the August issue of Current Directions in Psychological Science. Full reference
http://www.eurekalert.org/pub_releases/2007-08/afps-rpt082307.php
http://www.sciencedaily.com/releases/2007/08/070823142827.htm

How to benefit from memory training

Brain and memory training programs are increasingly popular, but they don't work well for everyone. In particular, they tend to be much less effective for those who need them the most — those 80 and older, and those with lower initial ability. But a new study shows the problem is not intrinsic, but depends on the strategies people use. The study found that people in their 60s and 70s used a strategy of spending most of their time on studying the materials and very little on the test, and showed large improvements over the testing sessions. By contrast, most people in their 80s and older spent very little time studying and instead spent most of their time on the test. These people did not do well and showed very little improvement even after two weeks of training.
The findings were published in the August issue of Psychological Science. Full reference
http://www.eurekalert.org/pub_releases/2007-08/uom-dpt082007.php

Age differences in cognitive benefits of exercise and mental stimulation

A mouse study has found that while physical exercise (a running wheel) and mental stimulation (toys), singly and together, improved memory in old mice, exercise alone or exercise and stimulation improved memory in middle-aged mice but not stimulation alone, and only exercise alone benefited young mice. The results suggest that as we get old and maybe less able to exercise, cognitive stimulation can help to compensate, but exercise is central to memory reinforcement at all ages.
The report appeared in the August issue of Behavioral Neuroscience. Full reference
Full text available at http://www.apa.org/journals/releases/bne1214679.pdf
http://www.eurekalert.org/pub_releases/2007-08/apa-eam080107.php

Aging adults have choices when confronting perceived mental declines

A researcher who has been studying changes we make – or fail to make – in the way we process and regulate our reading as we age has found that older adults who remember more of what they’ve read tend to have developed strategies to deal with the decline in some cognitive abilities that tends to occur as we get older. One thing they do is to spend more time building a “situation model” at the beginning of a story or book. They take time to get a feel for the setting, to get to know the characters, and to get grounded in important details of the story. This enables them to more easily integrate new information later on. They also pause longer and more often to integrate new concepts or to orient themselves to a change of setting in the text.
http://www.eurekalert.org/pub_releases/2007-08/uoia-aah080207.php

Brain network associated with cognitive reserve identified

An imaging study involving young (18-30) and older (65-80) adults has identified a brain network within the frontal lobe that is associated with cognitive reserve, the process that allows individuals to resist cognitive decline due to aging or Alzheimer’s disease. Those with higher levels of cognitive reserve were able to activate this network in the brain while working on more difficult tasks, while participants with lower levels of reserve were not able to tap into this particular network. The network was found more often in younger participants, suggesting the network may degrade during aging.
The findings were published online ahead of print August 3 in Cerebral Cortex. Full reference
http://www.eurekalert.org/pub_releases/2007-08/cumc-cri082007.php

Caffeine may protect memory in older women

A four-year study involving 7,000 people aged 65 and older found that women who drank more than three cups of coffee (or the equivalent in tea) per day had less decline over time on tests of memory (particularly verbal memory) than women who drank one cup or less of coffee or tea per day. These benefits increased with age – coffee drinkers being 30% less likely to have memory decline at age 65 and rising to 70% less likely over age 80. However, caffeine did not seem to have lower rates of dementia. Nor, rather bafflingly, did it have the same benefit in men.
The study was published in the August 7 issue of Neurology. Full reference
http://www.physorg.com/news105637026.html
http://www.eurekalert.org/pub_releases/2007-08/aaon-iwc073107.php
http://www.sciam.com/article.cfm?chanID=sa017&articleID=3CFB0625-E7F2-99DF-39C4208D730BE244

Removing ovaries before menopause increases risk of cognitive impairment

A very long-running study of some 1,500 women who underwent the removal of one or both ovaries for non-cancer-related reasons, has found that women who had one or both ovaries removed before menopause were nearly two times more likely to develop cognitive problems or dementia compared to women who did not have the surgery. In addition, those women who were younger when their ovaries were removed were more likely to develop dementia than women who were older when their ovaries were removed. This finding adds to other research suggesting that there may be a critical age window for the protective effect of estrogen on the brain in women.
The study was published online August 29 in Neurology. Full reference
http://www.eurekalert.org/pub_releases/2007-08/aaon-rob082107.php

Why learning takes a while

New findings about how new connections are made between brain cells sheds light on why it sometimes takes a little while before we truly ‘get’ something. It seems that, although connections are made within minutes, it takes eight hours before these connections are mature enough to transmit information, and more hours before the connections are firmly enough established to become fully functional synapses, likely to survive. It was also found that when a new spine made contact with a site already hosting a contact, the new spine was highly likely to displace the old connection. This may mean that newly learned information might lead to a fading of older information.
The report appeared in the July issue of The Journal of Neuroscience. Full reference
http://www.physorg.com/news106837506.html

Maturity brings richer memories

New research suggests adults can remember more contextual details than children, and that this is related to the development of the prefrontal cortex. While in a MRI scanner, 49 volunteers aged eight to 24 were shown pictures of 250 common scenes and told they would be tested on their memory of these scenes. In both children and adults, correct recognition of a scene was associated with higher activation in several areas of the prefrontal cortex and the medial temporal lobe when they were studying the pictures. However, the older the volunteers, the more frequently their correct answers were enriched with contextual detail. These more detailed memories correlated with more intense activation in a specific region of the PFC. A number of studies have suggested that the PFC develops later than other brain regions.
The report appeared in the August 5 advance online edition of Nature Neuroscience.
http://www.physorg.com/news105549812.html
http://www.eurekalert.org/pub_releases/2007-08/miot-msm080107.php

Why do children experience a vocabulary explosion at 18 months of age?

At about 18 months children experience a vocabulary explosion, suddenly learning words at a much faster rate. A new study using computer simulations suggests that the reason for this has little to do with brain maturity or cognitive development but is the result of several simple factors: the repetition of words over time, the fact that children learn many words at the same time, and the fact that words vary in difficulty. This factor, that children must be learning a greater number of difficult or moderate words than easy words, is crucial.
The findings were published in the August 3 edition of Science. Full reference
http://news.therecord.com/Wire/News_Wire/Science/article/223347
http://www.sciencedaily.com/releases/2007/08/070802182054.htm
http://www.sciam.com/article.cfm?chanID=sa017&articleID=2BFCF553-E7F2-99DF-34E7D16A89DCF458

Baby DVDs may hinder, not help, infants' language development

Random telephone interviews with more than 1,000 families found that for every hour per day spent watching baby DVDs and videos, infants eight to 16 months of age understood an average of six to eight fewer words than infants who did not watch them. Baby DVDs and videos had no positive or negative effect on the vocabularies on toddlers 17 to 24 months of age. Daily reading and storytelling by parents were, however, associated with slight increases in language skills. The researchers believe the content of baby DVDs and videos is different from the other types of programming because it tends to have little dialogue, short scenes, disconnected pictures and shows linguistically indescribable images.
The study was published online ahead of print August 8 in the Journal of Pediatrics. Full reference
http://www.eurekalert.org/pub_releases/2007-08/uow-bdv080307.php

The processes in reading

In a fascinating study, researchers have disentangled the three processes involved in reading: letter-by-letter decoding, whole word shape, and sentence context. They found that letter-by-letter decoding (phonics) determined 62% of reading speed, while context controlled 22% and word shape 16%.
The study was reported in the open access journal PLoS ONE. Full reference
http://www.sciam.com/article.cfm?chanID=sa017&articleID=22B713B3-E7F2-99DF-3616FB6450174BB8

Autism non-verbal not unintelligent

New findings suggest that the association of autism with low intelligence is a product of their language difficulties. Testing autistic kids and normal kids on two popular IQ tests — the WISC (which relies heavily on language) and Raven's Progressive Matrices (considered the best test of "fluid intelligence", and a test that doesn't require much language) found that while not a single autistic child scored in the "high intelligence" range of the WISC, a third did on the Raven's. A third of the autistics had WISC scores in the mentally retarded range, but only one in 20 scored that low on the Raven's test. The non-autistic children scored similarly on both tests. The same results occurred when the experiment was run on autistic and normal adults.
The results were reported in the August issue of Psychological Science. Full reference
http://www.physorg.com/news105376203.html
http://www.eurekalert.org/pub_releases/2007-08/afps-tmo080307.php

Gene predicts better outcome as cortex normalizes in teens with ADHD

Recent research found that thickening of brain areas that control attention in the right cortex (right orbitofrontal/inferior prefrontal and posterior parietal cortex ) was associated with better clinical outcomes in ADHD. A new study has found that these brain areas are thinnest in those who carry a particular variant of a gene. The version of the dopamine D4 receptor gene, called the 7-repeat variant, was found in nearly a quarter of youth with ADHD and about one-sixth of the healthy controls. Although this particular gene version increased risk for ADHD, it also made it more likely that the areas would thicken during adolescence, with consequent improvement in behaviour and performance.
The findings appeared in the August issue of Archives of General Psychiatry. Full reference
http://www.eurekalert.org/pub_releases/2007-08/niom-gpb080107.php