|
The Brain
Written and researched by Bob Murray, PhD
Latest News |
Back Issues | Get updates:
Subscribe Now
How Smart Kids Become Smart
May 3, 2002
Toddlers who physically explore their environment, engage socially with other children and verbally interact with adults are likely to have better scholastic and reading abilities as teenagers compared to less engaging toddlers. The reason, suggest the researchers, who study predictors of intelligence, is that these children create their own stimulating environment, thus facilitating their own cognitive ability.
These findings are reported in the April issue of the Journal of Personality and Social Psychology.
To determine this relationship between toddlers' stimulation- seeking behavior and later intelligence, psychologist Adrian Raine, PhD of the University of Southern California, and co-authors collected intelligence, cognitive and sociability measures on 1,795 children at age three. At age 11, the children's school achievement, reading ability and neuropsychological tests were evaluated and compared to the early measures.
Those three-year-olds that exhibited high stimulation behaviors at age three scored 12 points higher on total IQ at age 11 compared with low stimulation seekers. The high stimulation seekers also had superior scholastic and reading abilities at age 11. Gender, ethnic group and parents' education or occupation was ruled out as influences on a child's approach to new stimuli, according to the authors.
The authors believe that young children who actively learn about their environments by playing with other children and asking their parents questions create for themselves an enriched, stimulating, varied and challenging environment, said Dr Raine. "This enriched environment in turn results in enhanced cognitive ability and better school performance later on."
It could be, suggests Raine, that high levels of physical activity that don't involve social reciprocity may not necessarily facilitate or reflect superior intellectual performance in young children. Social involvement may be the crucial factor that increases cognitive ability later on. The social component of sensation-seeking at age three was a better predictor of superior cognitive abilities than other sensation-seeking components (eg, assembling blocks, copying shapes, identifying people and objects), said the authors. "The children who were more gregarious at age three had the higher intelligence scores."
Implications for these findings, according to Raine, are that "stimulation-seeking children may provide for themselves a more potent and continuous environmental enrichment than traditional educational enrichment can provide, and this environment, in contrast to programs, can produce long-term IQ changes that last throughout childhood.
This study reinforces what we have said for a long time -- that human kind is a social animal and thrives when given social stimulus. BM
Read more in the Journal of Personality and Social Psychology
Top of page
Smells Aren't Good Or Bad -- They're Learned
May 3, 2002
You'll never read a best seller called "The Joy of Smelling Skunks." It's a title that sounds as repulsive as skunk odor itself.
Yet not everybody finds skunk odor so unpleasant. In fact, claims psychologist Rachel Herz, most odors are inherently neither pleasant nor unpleasant. Odors are like the ABCs; you have to learn them, and you usually learn them young. You might even learn to like the smell of skunks.
Herz, of Brown University in Providence, RI, confesses her feelings for Pepe Le Pew in the latest issue of Cerebrum, a quarterly published by The Dana Forum on Brain Science -- an appropriate venue, as smell is, after all, the shortest route to the brain. A bit of the brain actually protrudes into the nostrils, in the form of small nerve cells that extend tiny cilia into the mucus that covers the nasal membrane. The cilia receive chemical messages that come from the air in the form of molecules carrying the essence of odors.
Odor molecules attach to the cilia at special molecules called receptors. Receptors come in different shapes; molecules attach to receptors whose shape they fit. A human nose might contain something like 20 million receptors, though only 300 to 400 specific types. Most experts believe the nature of an odor depends on the pattern of receptors activated by the arrival of properly shaped molecules. Activated neurons fire electrical signals along fibers called axons; the axons from different cells form the olfactory nerve, which carries the message to the brain's smell center. The smell center, it turns out, is right next door to the limbic system, the part of the brain involved in emotion. So odor experiences are quickly conferred with emotional significance.
Future responses to an odor may depend on the emotional circumstances in which the odor was first encountered, Herz contends. Several studies support her belief. Young children react the same to the smell of rancid cheese and banana. Infants don't discriminate between the smell of licorice and foul onion. Babies can learn to like certain smells, though they find certain perfumes pleasant if exposure to the scent is coordinated with cuddling.
Of course, children quickly learn which odors are foul and which are pleasant, but even then, curious anomalies arise. Herz finds skunk odor pleasant, for instance, because her first exposure to it came on a nice sunny day and her mother told her it was a nice smell.
Experiments with adults show that reaction to odor can be manipulated by context. Herz likes to trick people by giving the same odor a different label. "We have found that presenting exactly the same odor stimulus, but with two different labels can create an olfactory illusion," she writes in Cerebrum. So when a given odor is labeled "vomit," people react negatively, but they find the same odor pleasant if it is labeled "Parmesan cheese."
Read more on American Psychological Association's web site
Top of page
Antidepressants May Protect Against Neuronal Loss in Mood Disorders
March 25, 2002
According to Dr L Trevor Young, from McMaster University in Ontario, studies have shown that in the rat hippocampus and cerebral cortex, long-term treatment with antidepressants -- including selective serotonin reuptake inhibitors, tricyclics and monoamine oxidase inhibitors -- increases the expression of several target genes such as brain-derived neurotrophic factor (BDNF) and enhances neurogenesis.
Furthermore, long-term treatment with lithium and anticonvulsants increases the expression of several neuroprotectant factors in rodents. There are increasing reports of cell loss, both neuronal and glial, in key cerebral cortex regions in patients with mood disorders. Changes in the size of brain areas such as the hippocampus and amygdala have also been reported.
Postmortem studies suggest that antidepressant treatment may increase BDNF levels in the hippocampus and that lithium treatment may lead to small, but potentially relevant, increases in grey matter volume in patients with bipolar disorder. Dr Young said, "Enthusiasm and excitement about the neuroprotective effects of these psychotropic drugs is warranted, but more evidence is needed before clinicians can use this data to influence practice."
Researchers (especially those funded by the drug companies) are forever looking for new uses for antidepressants as the reality of their lack of effectiveness becomes more widely recognized. However the real point here is that depression, especially when it is due to early childhood trauma, causes a stunted development of certain areas of the brain and mis-wiring in others. Neurogenesis, the creation of new neurons (brain cells), thought impossible only a few years ago, is now seen as the great hope. Professional observers of our Uplift Program believe that the phenomenal success of the program can be explained by its ability to canalize the process of neurogenesis. BM
Read more in the Journal of Psychiatry and Neuroscience, January 27, 2002 editorial (pdf)
Top of page
Newly Born Cells in Adult Brain Act Like Other Neurons
March 11, 2002
Up until 1998 it was received wisdom that no new cells were ever created in the brain. Now we know better. However the new Salk findings offer proof that newly born cells integrate into existing neuronal circuitry, providing the brain with a continual reservoir of youthful active cells. Such cells might then replace older neurons or possibly be used to reshape the brain so it may learn and adapt to new experiences.
"This is the first demonstration that new cells that are born in the adult brain are functional," said Fred Gage, a professor at Salk and senior author of a study appearing in Nature that describes these results.
It was Gage who, in November 1998, discovered that adult humans, even among the elderly, can generate new brain cells throughout life in a process called neurogenesis. This landmark study upset long-held dogma that stated we are born with a full supply of brain cells that steadily diminish throughout our lives. Subsequent studies by Gage and his colleagues revealed that the number of new brain cells could be influenced by activity and other environmental stimuli. For example, the Gage team showed that running mice grow more brain cells in a region important for learning and memory -- the hippocampus — than their sedentary counterparts.
Despite such work, scientists still did not know if these new cells actually worked like any other neuron, or even if they grew and matured like other brain cells. The current study, which required the development of a new technique to measure electrical activity in living brain cells, should put those doubts to rest.
In their next studies, the Gage team hopes to determine what these new neurons actually do. "One possible hypothesis is that new neurons may be required to replace dying neurons," he said. "Another possibility is that young neurons provide a greater degree of plasticity to the mature brain. This enhanced plasticity would become apparent from the integration of new functional units whose connectivity may be shaped by experience."
One of the hopes for curing depression lies in repairing the damage to the hippocampus caused by early childhood trauma. One of the reasons why the Uplift Program works so well for depression (94% success rate in alleviating the symptoms of the illness) may be that it spurs neurogenesis to take place in that part of the brain. BM
Read more in Nature
Top of page
"Drying Out" Damages Emotion-Recognizing Brain Areas
March 11, 2002
Research on people's responses to photographs of different emotional facial expressions shows that heavy drinkers who had previously tried to kick the bottle are more likely than either non-alcoholics or alcoholics who had not previously experienced withdrawal symptoms to read fear and sadness in all emotional expressions.
The study, by experimental psychologist Dr Theodora Duka and research fellow Julia Townshend, has important implications for the treatment of alcoholics.
"If rehabilitation fails, we are left with alcoholics who are misinterpreting or exaggerating the emotions of those around them," says Dr Duka. "This can lead to more conflict in their environment, and more mental health problems."
The area of the brain that encodes the emotions of fear and sadness is the amygdala. Previous experiments using animals have shown that the repeated effects of alcohol withdrawal impair the functions of this area. For alcoholics with a history of detoxification, damage to the amygdala would result in their no longer being able to accurately interpret particular emotions.
The research also reveals that alcoholics in general are more likely to confuse the facial expressions of anger and disgust -- emotions that are believed to be encoded in the basal ganglia and orbitofrontal cortex of the brain. This confusion, however, is not related to the frequency of alcohol withdrawal, but is likely to be a symptom of long-term abuse.
Reported in Uniscience
Top of page
Gifted Few Make Order Out of Chaos
March 11, 2002
This is the finding of an Australian psychologist Dr Richard Heath, who has now moved to the UK's University of Sunderland. Heath tried to identify people who can make predictions in chaotic situations by showing volunteers a list of eight numbers and asking them to predict the next four.
The volunteers were told that the numbers were maximum temperatures for the previous eight days. In fact the numbers were computer-generated: some sets were part of a chaotic series while the rest were random.
Random sequences are by their nature unpredictable, whereas chaotic sequences follow specific rules. Despite this, chaotic sequences are very hard to predict in practice because of the "butterfly effect" -- even an unmeasurably small change in initial conditions can have a dramatic impact on their future state.
Nonetheless, Heath found that a quarter of the people he tested could predict the temperature for at least the next two days if the sequence was chaotic, rather than random, even though there is no obvious pattern to the figures.
"The $64,000 question is what is going on in their heads," says Heath. He is now planning studies to find out whether the skill is related to specific personality types, or to aspects of intelligence such as mathematical ability.
"It's sound. The effect looks real," says artificial intelligence expert Jeff Pressing of the University of Melbourne. He and others point to a crucial difference between this and previous studies claiming to show that people can identify the patterns in chaotic systems: Heath distinguished between the effects of chaos and other characteristics of the sequences that might help people make correct predictions.
In particular, Heath was able to exclude the possibility that the people making successful predictions were doing so by looking only at the last few numbers. In other words, they were not able to cheat by assuming that "the weather tomorrow is likely to be the same as the weather today."
If the finding does stand up, testing for sensitivity to chaos might help financial institutions identify people who would do well as financial traders. "Some guys can't communicate what they are doing, but they make millions," says Pressing. "They have some sort of intuition. My guess is that they are sensitive to subtle non-linear structures like chaos."
Read more in New Scientist
Top of page
Brain Disease Shaped Bolero
February 25, 2002
Brain disease influenced French composer Maurice Ravel's last compositions including his Bolero, say researchers. Orchestral timbres came to dominate his late music at the expense of melodic complexity because the left half of his brain deteriorated, they suggest. Timbre is mainly the province of the brain's right hemisphere.
Ravel suffered from a mysterious progressive dementia from about 1927 when he was 52 years old. He gradually lost the ability to speak, write and play the piano. He composed his last work in 1932, and gave his last performance in 1933. He died in December 1937.
Neurologists have puzzled over his illness ever since. Many have suggested Alzheimer's Disease. But Fran ois Boller, of the Paul Broca Research Center in Paris, believes the symptoms began too young, and that too much of Ravel's memory, self-awareness and social skills were preserved for this diagnosis to be correct.
Ravel probably suffered from two conditions, Boller proposes. One, progressive primary aphasia, erodes the brain's language centers. The other, corticobasal degeneration, robs patients of movement control. Ravel became trapped in his body, says Boller: "He didn't lose the ability to compose music, he lost the ability to express it."
The composer's failings, particularly his loss of language, were predominantly in faculties dealt with by the left half of the brain. Musical abilities are spread throughout the brain; different areas deal with pitch, melody, harmony and rhythm.
Boller and his colleagues believe that two of Ravel's last pieces show the early effects of the weakening left hemisphere, with the timbre-processing =ight brain coming to the fore. The works are Bolero, written in 1928, and his 1930 piano concerto for the left hand.
Not everyone agrees, however.
"Bolero occupies a funny place in Ravel's oeuvre," says Deborah Mawer, a music researcher at Lancaster University, UK. "But it's hard to distinguish between his musical development and his gradually altering mental state," she cautions. Ravel became interested in mechanization and modern machinery at the end of his life, which could account for the repetitiveness of the piece.
When I studied music at school I was told that Bolero's origin was in a bet that Ravel made with a lady music critic. He wagered that he could write a piece lasting some twenty minutes with but one theme and have it accepted for performance. She, silly woman, took him on and lost. Bolero is probably Ravel's crowning achievement -- whichever side of the brain it comes from! BM
Read more in Nature
Top of page
Mentally Stimulating Activities May Reduce Alzheimer's Risk
February 25, 2002
In recent years, we have come to believe that doing something new -- a new exercise, a new game, crossword puzzles etc. might ward off a decline in memory or help us maintain "brainpower" as we age. Now, a new study suggests there might be some truth to the use-it-or-lose-it hypothesis.
The study, by scientists at the Rush Alzheimer's Disease Center and Rush-Presbyterian-St. Luke's Medical Center in Chicago, IL, appearing in the Journal of the American Medical Association, found that more frequent participation in cognitively stimulating activities is associated with a reduced risk of Alzheimer's Disease (AD). The research looked at everyday activities like reading books, newspapers or magazines, engaging in crosswords or card games, and going to museums among participants in the Religious Orders Study, an ongoing examination of aging among older Catholic nuns, priests, and brothers from several groups across the US.
The study followed over 700 dementia-free participants age 65 and older for an average of 4.5 years from their initial assessments. At baseline and then yearly, some 21 cognitive tests were administered to assess various aspects of memory, language, attention, and spatial ability. At the initial evaluations, participants also were asked about time typically spent in seven common activities that significantly involve information processing -- viewing television; listening to the radio; reading newspapers or magazines; reading books; playing games such as cards, checkers, crosswords, or other puzzles; and going to museums. The frequency of participating in each activity was rated on a five-point scale, with the highest point assigned to participating in an activity every day or about every day and the lowest point to engaging in an activity once a year or less.
During the follow-up period, 111 people in the study developed AD. In comparing the levels of cognitive activity with diagnosis of AD, the researchers found that the frequency of activity was related to the risk of developing AD. For each one point increase in the participants' scores on the scale of cognitive activities, the risk of developing AD decreased by 33 percent.
On average, compared with someone with the lowest activity level, the risk of disease was reduced by 47 percent among those whose frequency of activity was highest.
The main way to ward off Alzheimer's Disease is to expose the brain to new things -- make it work in novel ways. We do this in the Uplift Program. We also do this in our Repatterning Movement (RPM) exercises. These gentle exercises have been shown to be effective in stimulating mental activity. BM
Read more in the Journal of the American Medical Association
Top of page
Alcohol Could Reduce Dementia Risk
February 10, 2002
It is known that light-to-moderate consumption lessens the risk of coronary heart disease and stroke, but Dutch scientists think it could be good for mental health.
The team at Erasmus University Medical School in Rotterdam compared the risk of developing dementia between individuals who regularly consumed alcohol with those who did not consume alcohol.
Light-to-moderate alcohol consumption (one to three drinks a day) was associated with a 42% risk reduction of all dementia and about a 70% reduction in risk of vascular dementia (dementia caused by a series of small strokes).
Out of 8,000 people who took part, 197 individuals developed dementia — of these, 146 had Alzheimer's disease, 29 developed vascular dementia and 22 got other types of dementia, it is reported in the Lancet medical journal.
The team suggests alcohol may have a direct effect on brain activity by stimulating the release of the chemical acetylcholine in the hippocampus area of the brain. Acetylcholine is known to facilitate memory and learning processes, however high alcohol intake inhibits acetylcholine production.
Monique Breteler, who led the research, said: "In recent years, evidence has been accumulating that vascular factors may be involved in the cause of dementia, both vascular dementia and Alzheimer's disease. Our findings lend further support to the vascular hypothesis of dementia.
"We saw some indication for a stronger relation with alcohol in persons with a genetically determined susceptibility for Alzheimer's disease. Our findings can help focus research into the specific mechanisms that underlie the development of dementing illnesses."
Alzheimer's disease is the most common cause of dementia, accounting for 50% of all cases. Vascular dementia accounts for about 20% of cases.
All those taking part in the research were aged 55+ and did not have dementia at the start of the study.
Read more in BBC News
Top of page
Social Status Determines Drug Addiction
February 10, 2002
Social standing — being dominant or subordinate — plays a crucial role in deciding whether an individual will become a drug abuser, according to scientists at Wake Forest University in North Carolina.
The researchers have discovered that macaque monkeys that were deemed to be subordinate were more likely to give themselves doses of cocaine in a laboratory setting than dominant animals.
In a study published in Nature: Neuroscience the scientists claim that the brain chemistry of the lower ranking monkeys and those of higher status were markedly different and this difference leads to the drug abuse by the lower ranked macaques. The main difference lies in the amount of dopamine that the central brain of the monkeys generates. Dopamine, the reward chemical, is closely related to addiction of all kinds in humans as well as other primates.
Generally the less dopamine the brain produces naturally the more susceptible the individual is to addiction.
What has now been discovered is that the dominant monkeys experienced an increase in a type of dopamine receptor (i.e. a brain cell specialized in uptaking that neurochemical) and were thus less liable to cocaine abuse.
Dr Michael Nader, who led the study, said that the research showed that social or environmental changes (i.e. moving up or down the social scale) can have an impact on brain chemistry relating to sensitivity to an addictive drug. This finding could have parallels in humans.
We have been saying for some time that the answer to addiction was two-fold: raising the addict's level of self-esteem and teaching the brain to look for other reward stimuli (for example good relationships). Both of these are covered in our Uplift Program. BM
Read more in Nature
Top of page
RELATED LINKS
Check our event schedule for workshops and seminars.
About the Author
Dr Bob Murray is a widely published psychologist and expert on emotional health and optimal relationships. Together with his wife and long-term collaborator Alicia Fortinberry, he is founder of the highly successful Uplift Program, and author of Raising an Optimistic Child (McGraw-Hill, 2006) and Creating Optimism (McGraw-Hill, 2004).
Do you like our site? Recommend this page to a friend!
|
