News reports of research into memory November 2006

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November 2006

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.
The study was reported in the November issue of the Journal of Experimental Psychology: General. Full reference
http://www.eurekalert.org/pub_releases/2006-11/apa-tsr110606.php

Rote learning may improve verbal memory in seniors

A study involving 24 older adults (aged 55—70) has found that six weeks of intensive rote learning (memorizing a newspaper article or poem of 500 words every week) resulted in measurable changes in N-acetylaspartate, creatine and choline, three metabolites in the brain that are related to memory performance and neural cell health, in the left posterior hippocampus — but only after a six-week rest period, at which time the participants also showed improvements in their verbal and episodic memory, and also only in one of the two learning groups. The group that didn’t show any change were said to have low compliance with the memorization task.
The study was presented at the annual meeting of the Radiological Society of North America (RSNA). Reference
http://www.eurekalert.org/pub_releases/2006-11/rson-rli112206.php

Iron-deficient infants have lower cognitive scores at 19, especially in lower socioeconomic levels

Another study has come out finding that teenagers who were iron-deficient as infants continue to lag behind their peers in cognitive test scores, with a wider gap for children at lower socioeconomic levels. The study of 185 children from an urban area in Costa Rica, found that among children from middle-class families, initial scores on cognitive tests were eight points apart, 101.2 for those with iron deficiency and 109.3 for those with sufficient iron levels, and this gap remained at eight or nine points through 19 years. However, for those in lower socio-economic classes, initial scores that were ten points apart (93.1 for iron-deficient infants and 102.8 for those with normal iron levels) had widened by 19 years to 25 points (70.4 vs. 95.3). The finding points to the snowball effect of early failure.
The study was published in the November issue of Archives of Pediatrics & Adolescent Medicine. Full reference
http://www.eurekalert.org/pub_releases/2006-11/jaaj-idi110206.php

How whole-brain radiation might cause dementia

Whole-brain radiation is widely used to treat recurrent brain tumors as well as to prevent other cancers from spreading to the brain. About a half of patients later develop progressive memory problems. A new study has now identified changes in brain chemistry that may be responsible. Using middle-aged rats, researchers found changes in brain receptors for the neurotransmitter glutamate. The changes may impair synaptic communication.
The research was reported at the annual meeting of the Radiation Research Society in Philadelphia.
http://www.eurekalert.org/pub_releases/2006-11/wfub-ssp103006.php

Common cancer treatments toxic to healthy brain cells

A new study may explain ‘chemo-brain’ (cognitive dysfunction following chemotherapy). The study reveals that common drugs used to treat cancer are far more toxic to healthy brain cells than cancer cells — typical exposure levels killed 70-100% of brain cells but just 40-80% of the cancer cells. Moreover, the healthy cells continued to die for at least six weeks after treatment. Now the task is to find out how to protect healthy cells from the drugs.
The full article is available at: http://jbiol.com/content/5/7/22
The study was published in the Journal of Biology. Full reference
http://www.eurekalert.org/pub_releases/2006-11/uorm-cct112806.php

Chemotherapy temporarily affects the brain

A new study has found that although significant regions of the brain associated with cognitive function were significantly smaller in breast cancer patients within 12 months of receiving adjuvant chemotherapy, after three years, there were no differences in these regions between those who had received chemotherapy and those who had not.
The study was published online 27 November and will appear in the January 1 issue of CANCER. Full reference
http://www.eurekalert.org/pub_releases/2006-11/jws-cta112006.php

Ecstasy can harm the brains of first-time users

Ecstasy targets neurons in the brain that use serotonin to communicate. Previous studies have found that long-term or heavy ecstasy use can damage these neurons and cause depression, anxiety, confusion, difficulty sleeping and decrease in memory. Now research into the effects of low doses on first-time users has revealed a decrease in blood circulation in some areas of the brain, along with a relative decrease in verbal memory performance in ecstasy users compared to non-users.
The findings were presented at the annual meeting of the Radiological Society of North America (RSNA). Reference
http://www.eurekalert.org/pub_releases/2006-11/rson-ech112106.php

Hormone replacement therapy may improve visual memory of postmenopausal women

A study of 10 postmenopausal women (aged 50-60) found that those taking combined estrogen-progestin hormone therapy for four weeks showed significantly increased activity in the prefrontal cortex when engaged in a visual matching task, compared with those on placebo.
The study was reported in the November issue of The Journal of Clinical Endocrinology & Metabolism. Full reference
http://www.eurekalert.org/pub_releases/2006-11/uomh-hrt111606.php

Toddlers can learn complex actions from picture-book reading

A study of preschool children has found picture books not only encourage reading development, but also help toddlers learn about the real world. However, very young children (18 months) were much less likely to be able to imitate specific target actions on novel real-world objects when the pictures were colored-pencil drawings rather than life-like color photographs.
The study appeared in the November issue of Developmental Psychology. Full reference
Full text of the article is available at http://www.apa.org/journals/releases/dev4261352.pdf
http://www.eurekalert.org/pub_releases/2006-11/apa-tlc103006.php

How the brain detects novelty

New research suggests that the hippocampus makes predictions of what will happen next by automatically recalling an entire sequence of events in response to a single cue, allowing us to anticipate future events and detect when things do not turn out as expected. Rather than reacting to novelty, the hippocampus seems to act as a comparison device, matching up past and present experience.
The research is published today in Public Library of Science Biology. Full reference
The full text is available at http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0040424
http://www.eurekalert.org/pub_releases/2006-11/wt-tot112406.php