The American Academy of Neurology has updated its guidelines on when people with dementia should stop driving. While the guidelines point out that this decision is a complex one that should be made by a doctor using the Clinical Dementia Rating scale, they also supported caregivers’ instincts, which have been found to often be correct. For caregivers and family members, the following warning signs are identified:

Another gene has been identified that appears to increase risk of Alzheimer’s. The gene, MTHFD1L, is located on chromosome six. Comparison of the genomes of 2,269 people with late-onset Alzheimer's disease and 3,107 people without the disease found those with a particular variation in this gene were almost twice as likely to develop Alzheimer's disease as those people without the variation.

The Phase II clinical trial of a treatment using naturally occurring antibodies (IGIV) has achieved significantly lower rates of ventricular enlargement (6.7% vs 12.7% per year) and less whole-brain atrophy (1.6% vs 2.2% per year) than control subjects who initially received placebo. The trial ran for 18 months and involved 24 patients with mild to moderate Alzheimer's disease, of whom 16 received IGIV once or twice a month for the whole period, and 8 received a placebo for the first 6 months.

Previous research has found that unexplained weight loss is an early sign of Alzheimer's. Now a study involving 140 older adults (60+), of whom half had early-stage Alzheimer's disease, has revealed that it is not the overall weight or fat levels that are important, but the loss of lean mass (weight of an individual's bones, muscles and organs without body fat). This directly correlated with reductions in the volume of the whole brain and of

Two mouse experiments have found that the drug carvedilol, prescribed for the treatment of hypertension, significantly improved synaptic transmission in Alzheimer's disease-type brains, and at a behavioral level significantly improved learning and memory.

Amnestic mild cognitive impairment often leads to Alzheimer's disease, but what predicts aMCI? A study involving 94 older adults has revealed that lower performance on tests measuring learning, in conjunction with either slower visuomotor processing speed or depressive symptoms, predicted the development of aMCI a year later with an accuracy of 80-100%. It is worth emphasizing that poor learning alone was not predictive in that time-frame, although one learning measure was predictive of aMCI two years later.

A pilot study involving 21 institutionalized individuals with moderate-to-severe Alzheimer’s found that, although drinking two 4-oz glasses of apple juice daily for a month produced no change in the Dementia Rating Scale or in the Activities of Daily Living measure, there was a significant (27%) improvement in behavioral and psychotic symptoms. The largest changes occurred in anxiety, agitation, and delusion.

A pilot study involving 10 patients with moderate Alzheimer's disease, of whom half were randomly assigned to the treatment, has found that two weeks of receiving daily (25 minute) periods of repetitive transcranial magnetic stimulation to the prefrontal

A study involving outpatients with early stage Alzheimer’s found that their performance on some computerized tests of executive function and visual attention, including a simulated driving task, improved significantly after three months of taking cholinesterase inhibitors.

We know that lead damages the brain, and that it does so by somehow affecting the release of neurotransmitters at synapses (the process by which neurons pass messages on). Now a new study explains exactly what lead does. Apparently, during the formation of synapses, lead lowers the levels of key proteins involved in neurotransmitter release (synaptophysin and synaptobrevin), and reduces the number of fast-releasing sites. These effects may occur through the inhibition of the NMDA receptor (which produced similar effects), disrupting the release of BDNF.

For a long time, it has been assumed that mammals have different (better!) brains than other animals — partly because of the highly convoluted neocortex. Specifically, the mammalian neocortex features layers of cells (lamination) connected by radially arrayed columns of other cells, forming functional modules characterized by neuronal types and specific connections. Early studies of homologous regions in nonmammalian brains found no similar arrangement.

Previous research has found that individual neurons can become tuned to specific concepts or categories. We can have "cat" neurons, and "car" neurons, and even an “Angelina Jolie” neuron. A new monkey study, however, reveals that although some neurons were more attuned to car images and others to animal images, many neurons were active in both categories. More importantly, these "multitasking" neurons were in fact the best at making correct identifications when the monkey alternated between two category problems.

Three experiments involving students who had lived abroad and those who hadn't found that those who had experienced a different culture demonstrated greater creativity — but only when they first recalled a multicultural learning experience from their life abroad. Specifically, doing so (a) improved idea flexibility (e.g., the ability to solve problems in multiple ways), (b) increased awareness of underlying connections and associations, and (c) helped overcome functional fixedness.

A rat study reveals that, for rats at least, an understanding of place and a sense of direction appears within two weeks of being born, seemingly independently of any experience of the world. The directional signal, which allows the animal to know which way it is facing, is already at adult levels as soon as it can be measured in newborn rats. Sense of place is also present early, but improves with age. Representations of distance appear a few days later.

Because Nicaraguan Sign Language is only about 35 years old, and still evolving rapidly, the language used by the younger generation is more complex than that used by the older generation. This enables researchers to compare the effects of language ability on other abilities. A recent study found that younger signers (in their 20s) performed better than older signers (in their 30s) on two spatial cognition tasks that involved finding a hidden object. The findings provide more support for the theory that language shapes how we think and perceive.

As I get older, the question of how we perceive speech becomes more interesting (people don’t talk as clearly as they used to!). So I was intrigued by this latest research that reveals that it is not so much a question of whether consonants or vowels are more important (although consonants do appear to be less important than vowels — the opposite of what is true for written language), but a matter of transitions.

Why do women tend to be better than men at recognizing faces? Two recent studies give a clue, and also explain inconsistencies in previous research, some of which has found that face recognition mainly happens in the right hemisphere part of the face fusiform area, and some that face recognition occurs bilaterally. One study found that, while men tended to process face recognition in the right hemisphere only, women tended to process the information in both hemispheres.

A new study challenges the popular theory that expertise is simply a product of tens of thousands of hours of deliberate practice. Not that anyone is claiming that this practice isn’t necessary — but it may not be sufficient. A study looking at pianists’ ability to sight-read music reveals

Data from North Carolina's mandated End-of-Grade tests (2000-2005), which includes student reports on how frequently they use a home computer for schoolwork, watch TV or read for pleasure, reveals that students in grades five through eight (c.10-13), particularly those from disadvantaged families, tended to have lower reading and math scores after they got a home computer. The researchers suggest that the greater negative effect in disadvantaged households may reflect less parental monitoring.

A study following 1,323 children in Grades 3 to 5 and 210 college students has found that children who exceeded two hours per day of screen time (TV and video games) were 1.5 to two times more likely to be considered above average in attention problems by their teachers compared to children who met the guideline. A similar association between screen media time and attention problems (self-reported) was found for the college students. A study earlier this year found U.S.

Analysis of 30 years of SAT and ACT tests administered to the top 5% of U.S. 7th graders has found that the ratio of 7th graders scoring 700 or above on the SAT-math has dropped from about 13 boys to 1 girl to about 4 boys to 1 girl. The ratio dropped dramatically between 1981 and 1995, and has remained relatively stable since then. The top scores on scientific reasoning, a relatively new section of the ACT that was not included in the original study, show a similar ratio of boys to girls.

A study involving 135 adults (33-65) has found that, not only did patients with obstructive sleep apnea who were being treated with CPAP therapy outperform untreated OSA patients on an overnight picture memory task, but they outperformed controls who did not have OSA. The memory task involved being shown 20 photographs before spending the night in the sleep lab, and then having to choose the familiar photo from 20 similar pairs in the morning. CPAP therapy provides a steady stream of air through a mask that is worn during sleep.

A study involving 163 overweight children and adolescents aged 10 to 17 has revealed that moderate to severe obstructive sleep apnea was linked to both lower academic grades and behavioral concerns. None of the students with moderate to severe OSA had an "A" average, and 30% had a "C" average or lower. In contrast, roughly 15% of those without sleep-disordered breathing had an "A" average, and only about 15% had a "C" average or lower. The results remained significant after adjustment for sex, race, socioeconomic status and sleep duration on school nights.

A number of studies have shown the benefits of sleep for consolidating motor learning. A new study extends this research to a more complex motor task: "Guitar Hero III", a popular video game. There was significantly greater improvement after a night’s sleep (average 68% in performance accuracy vs 63% for students who learnt the task in the morning and were tested in the evening), and a significant correlation between sleep duration and the amount of improvement.

A national study involving some 8,000 children, has revealed receptive and expressive language, phonological awareness, literacy and early math abilities were all better in 4-year-old children whose parents reported having rules about what time their child goes to bed. Having an earlier bedtime also was predictive of higher scores for most developmental measures. Recommendations are that preschool children get a minimum of 11 hours of sleep each night.

It’s not just a matter of quantity; quality of sleep matters too. A study involving 72 adults (average age 40), whose sleep was monitored for 11 consecutive nights, has revealed that reaction times on a morning psychomotor vigilance task was significantly slower after exposure to recorded traffic noise during sleep. The slowing was directly related to the frequency and sound-pressure level of the nightly noise.

A study using data on reported homicides in Chicago 1994-2002 and two independent surveys of children and families in Chicago, has revealed that African-American children who were assessed directly after a local homicide occurred scored substantially lower on vocabulary and reading assessments than their peers from the same neighborhood who were assessed at different times. The impact of the homicide faded both with time and distance from the child's home.

A new analysis of data first published in 2002 in a controversial book called IQ and the Wealth of Nations and then expanded in 2006, argues that national differences in IQ are best explained not by differences in national wealth (the original researchers’ explanation), but by the toll of infectious diseases. The idea is that energy used to fight infection is energy taken from brain development in children.

A study involving 54 older adults (66-76) and 58 younger adults (18-35) challenges the idea that age itself causes people to become more risk-averse and to make poorer decisions. Analysis revealed that it is individual differences in processing speed and memory that affect decision quality, not age. The stereotype has arisen no doubt because more older people process slowly and have poorer memory.

A rhesus monkey study has revealed which dendritic spines are lost with age, providing a new target for therapies to help prevent age-association cognitive impairment. It appears that it is the thin, dynamic spines in the dorsolateral prefrontal cortex, which are key to learning new things, establishing rules, and planning, that are lost. Learning of a new task was correlated with both synapse density and average spine size, but was most strongly predicted by the head volume of thin spines.

A large longitudinal study, comparing physical activity at teenage, age 30, age 50, and late life against cognition of 9,344 women, has revealed that women who are physically active at any point have a lower risk of cognitive impairment in late-life compared to those who are inactive, but teenage physical activity is the most important. When age, education, marital status, diabetes, hypertension, depressive symptoms, smoking, and BMI were accounted for, only teenage physical activity status remained significantly associated with cognitive performance in old age.

Memory and learning problems often occur in multiple sclerosis, but bewilderingly, are only weakly associated with the severity of the disease. A study involving 44 people around the age of 45 who had MS for an average of 11 years has found that those with a mentally active lifestyle had good scores on the tests of learning and memory even if they had higher amounts of brain damage. The findings suggest that, as with Alzheimer’s disease, 'cognitive reserve' protects against cognitive impairment.

A study involving 629 12th-grade students from three Los Angeles-area high schools has revealed that, across both genders and all ethnicities, adolescents with more in-school friends, compared with out-of-school friends, had higher grade point averages. It’s assumed that this is due to the fact that in-school friends are more likely to support school-related activities, including studying.

A study involving 733 participants from the Framingham Heart Study Offspring Cohort (average age 60) provides more evidence that excess abdominal fat places otherwise healthy, middle-aged people at greater risk for dementia later in life. The study also confirms that a higher BMI (body mass index) is associated with lower brain volumes in both older and middle-aged adults. However the association between visceral fat and total brain volume was independent of BMI. Visceral fat differs from subcutaneous fat in that it is buried deeper, beneath the muscles, around the organs.

A 12-year study involving 1,221 married couples ages 65 or older (part of the Cache County (Utah) Memory Study) has revealed that husbands or wives who care for spouses with dementia are six times more likely to develop Alzheimer’s themselves than those whose spouses don't have it. The increased risk is of comparable size to having the ‘Alzheimer's gene’. The researchers speculate that the great stress of caregiving might be responsible for the increased dementia risk, emphasizing the need for greater caregiver support.

A comprehensive study reveals how the ‘Alzheimer's gene’ (APOE ε4) affects the nature of the disease. It is not simply that those with the gene variant tend to be more impaired (in terms of both memory loss and brain damage) than those without. Different parts of the brain (and thus different functions) tend to be differentially affected, depending on whether the individual is a carrier of the gene or not. Carriers displayed significantly greater impairment on tests of memory retention, while noncarriers were more impaired on tests of working memory, executive control, and lexical access.

A study involving 379 individuals who abstained from caffeine for 16 hours has revealed little variance in levels of alertness after receiving caffeine. Those who were medium/high caffeine consumers reported a decrease in alertness and an increase in headache if given the placebo, neither of which were reported by those who received caffeine. However, their post-caffeine levels of alertness were no higher than the non/low consumers who received a placebo, suggesting caffeine only brings coffee drinkers back up to 'normal'.

A special supplement in the Journal of Alzheimer's Disease focuses on the effects of caffeine on dementia and age-related cognitive decline. Here are the highlights:

A mouse study has found memory restoration and lower levels of amyloid-beta in Alzheimer’s mice following only 1-2 months of caffeine treatment. The researchers talk of “ a surprising ability of moderate caffeine intake to protect against or treat AD”, and define moderate intake as around 5 cups of coffee a day(!).