Treating Medically Unexplained Symptoms

It's Not Fair! We Are Programmed To Resist Weight Loss

Small Percentage of Violent Crime Attributable to Mental Illness

Women who commit a violent crime may be more likely to have severe mental illness than men who commit a violent crime.

Patients with severe mental illness commit approximately 1 in 20 violent crimes, according to a study of mental illness and violence in Sweden.

Researchers using Swedish national registry data determined that the overall contribution of patients with severe mental illness to violent crime in Sweden between 1988 and 2000 was about 5 percent.

"Although Sweden is average for Western Europe in terms of violent crime per head of population, it has lower rates of homicides than countries with more liberal gun-ownership laws," wrote study authors Seena Fazel, M.B.Ch.B., and Martin Grann, C.Psych. Ph.D., in the August American Journal of Psychiatry. "This will alter the attributable risk for homicide, which is likely to be lower in countries such as the United States, but it is unlikely to substantially modify the overall attributable risk for violent crime, which is mostly accounted for by much more common crimes, such as assault."

They linked 98,082 individuals discharged with an ICD diagnosis of schizophrenia to a national crime registry to determine the population-attributable risk of patients with severe mental illness to violent crime. Population-attributable risk is an epidemiologic term referring to the proportion of any disease or phenomenon (in this case, violence) that is attributable to a risk factor (in this case, severe mental illness).

Though the measure does not estimate the dangerousness of any one individual with mental illness, it does provide a population perspective on the extent to which mental illness contributes to violent crime.

The researchers found that over a 13-year period, there were 45 violent crimes committed per 1,000 inhabitants. Of these, 2.4 were attributable to patients with severe mental illness, corresponding to a population-attributable risk of 5.2 percent.

The attributable risk was higher in women than men across all ages: in women aged 25 to 39 it was 14 percent, and in women over age 40 it was 19 percent. It was lowest in the 15 to 24 age group—2.3 percent for men and 2.9 percent for women.

"This population study demonstrated that the overall contribution of patients with severe mental illness to such crime was about 5 percent in Sweden between 1988 and 2000," wrote Fazel and Grann. "Although this contribution varied by gender, age, and type of violent crime, this finding should generate a more informed debate on the contribution of persons with severe mental illness to societal violence."

Source: Psychiatric News
http://pn.psychiatryonline.org/cgi/content/full/41/17/25-a?etoc

Posted by
Robert Karl Stonjek

Mental Leap

What apes can teach us about the human mind

Eric Jaffe

At the opening of Stanley Kubrick's 1968 film 2001: A Space Odyssey, a group of apes hovers around an object that has suddenly appeared in the desert. The sleek, black, rectangular object is five times as tall as the apes and clearly crafted by intelligent beings. The apes approach it with caution, and one animal runs a timid hand along the clean edges that glimmer in the sunlight.

A chimpanzee uses a stick as a fishing rod at Arnhem Zoo in the Netherlands. Apes' use of tools has suggested to some researchers that certain human mental capabilities trace back 14 million years to common ancestors of apes and humans. Frans de Waal

Suddenly, something clicks in the ape's mind. The sight of a sophisticated innovation has launched dormant aptitudes, and the ape has realized that a large bone can be used as a weapon to advance its kind. Standing more erect than before and brandishing the weapon, the ape attacks another group.

The film then fast-forwards through the remainder of cognitive evolution in a flash: The bone, tossed into the air, becomes a space station floating through the cosmos.

Too bad the camera didn't cut instead to a laboratory at the Max Planck Institute in Leipzig, Germany, where scientists are discovering details about apes' brains that could fill in some of the movie's multimillion-year gap. Researchers at the institute, Josep Call and Nicholas Mulcahy, recently demonstrated that apes possess a surprising understanding of tools and even make plans to use them. In fact, the study suggests that planning skills go back 14 million years to ancestors of apes and people.

Two other knacks once considered unique to humans have recently turned up in apes. A team of scientists watching apes at the Yerkes Primate Center at Emory University in Atlanta reports that the animals conform to cultural norms—that is, they do a task the same way that others in a group do it, even if an alternative method exists.

Another team studying apes raised at the Language Research Center at Georgia State University, also in Atlanta, concludes that young animals play make-believe, an activity considered an early sign of linguistic abilities.

These studies represent an effort to understand some of the human mind's fundamental mechanisms. While recognizing a difference in the degree of human and ape capabilities, "I don't think there's a difference in kind," says Call.

Investigating these differences could reveal "the processes that led to our position," says Carel van Schaik, director of the Anthropological Institute and Museum at the University of Zurich in Switzerland. "We can build a bridge across the [ape-human] gap without denying that there are some really big differences."

Planning of the apes

For Call and Mulcahy, the most fitting metaphor for ape cognition isn't A Space Odyssey but an Estonian folktale. In that story, a young girl dreams of attending a party where she can't eat dessert because she has no spoon. The next night, the girl takes a spoon to bed, in case the dream recurs.

GREAT GRAPE. An ape carries pipes that it can use to retrieve grapes locked in a container. In an experiment, apes showed the foresight to save such tools for future use. J. Kalbitz/MPI-EVA

The scientists placed bonobos and orangutans in a similar scenario. Previous studies had clearly shown that apes use tools to satisfy an immediate need. In the wild, for example, they frequently transport rocks to smash open nuts. But the researchers wanted to know whether apes would hold on to a tool that they wouldn't need until much later.

Before the test, the apes had learned how to retrieve a bunch of grapes locked inside a container. The apes had to insert a thin plastic pipe into a slot, as though the pipe were a key. In the test, Call and Mulcahy led the apes, one at a time, into a test room where each animal saw the grape-holding container and four objects: a dowel, a plastic dish, a bowl, and the slot-fitting pipe.

Here, the experiment went beyond observations of tool use. A Plexiglas panel blocked the container, so the ape couldn't retrieve the grapes, even with the right tool. Each animal was free to take away an object when it left the room and wasn't permitted to return for an hour.

By then, the researchers had removed the Plexiglas and all the tools. An ape that had selected the right tool, removed it from the test room, and brought it back after the delay could then help itself to grapes. In other words, the successful animals planned ahead.

The test was performed 16 times for each of three bonobos and three orangutans. On average, each ape solved the task 7 times, with one ape solving it 15 times and another only twice. The animals improved slightly as they repeated the test.

The best-performing bonobo and orangutan were brought back for a more difficult test. In 16 additional trials, each of these two apes visited the test room and then was kept out of it overnight, yet about half the time they carried the appropriate tool into the room the next morning.

But, the most impressive display of sophisticated thinking, Mulcahy says, came from an unexpected incident. An orangutan brought back the wrong tool and then shaped it into a usable key.

To learn whether the apes were carrying the tools simply by force of habit or because they enjoyed doing so, Call and Mulcahy performed another test, in which they repeatedly removed the grapes after a first showing behind the Plexiglas. That way, the apes could learn that there was no reason to haul the tool around—after all, why bring a spoon to a party without desserts?

Sure enough, two of the apes in this trial never brought along the pipe. The two other animals in this trial seldom did so, the researchers reported in the May 19 Science.

Mulcahy argues that the animals' delayed success depends on them making a realization similar to that of the girl in the folktale, who had to fail—at least in her dream—before she could plan ahead.

Since bonobos and orangutans both solved the tasks, Call and Mulcahy concluded that the cognitive seeds for planning were already in place at least 14 million years ago, when a common ancestor to these apes and humans lived.

Van Schaik comments that he frequently sees evidence of planning from apes in the wild. For example, orangutans often give "long calls" to let others know the direction in which they're going to travel a couple hours later, he says. While this action isn't the same as considering retirement options, the long calls suggest that apes might at least plan their afternoons.

But some other researchers are skeptical of the new data. Clutching a tool to get grapes doesn't demonstrate planning, says Daniel Povinelli, who is director of the Cognitive Evolution Group at the University of Louisiana at Lafayette.

The apes weren't necessarily thinking about the task ahead when they selected the pipe. They had been trained to use it but had no experience with the other tools, which "might as well be books of Shakespeare," Povinelli says.

Moreover, the apes might have learned to associate having the pipe with success in getting the grapes, which is a simpler mental function than planning. Povinelli points out that most of the apes didn't consistently bring back the pipe until halfway through the experiment, which is what he'd expect for the association explanation. "The fact they carry [the tool] isn't evidence to their conception of the future," he says.

Despite Povinelli's criticism, a commentary accompanying the paper says that the study might someday be considered a landmark. Call and Mulcahy demonstrate "the most extensive foresight yet in nonhuman primates," writes cognitive psychologist Thomas Suddendorf of the University of the University of Queensland in Australia. "This provides a starting point from which we can begin to reconstruct the evolution of the human mind," he says.

Swamp smarts

Other recent experiments also suggest humanlike cognition in apes. Last year, researchers working at Emory found evidence that animals conform to cultural influences in the same way that people do (SN: 9/3/05, p. 158: Available to subscribers at http://www.sciencenews.org/articles/20050903/note16.asp). Such cultural conformity, for example, motivates a person to bow in greeting in Japan but to shake hands in the United States.

METHOD ACTING. A chimpanzee pokes a device to release food. Even though most apes learned that the trigger could be either poked or lifted, they usually chose the method of their group leader—a sign of conforming to cultural norms. de Waal /Yerkes National Primate Research Center

In the study, two groups of apes learned to operate a device that releases food when a trigger is either lifted or poked. In each group, subordinate apes predominantly got the food in the same way—a lift or a poke—that their group leader did. Because they occasionally pulled instead of poked, or vice versa, the animals had learned both techniques during repeated trials. But when the apes were retested 2 months later, they still overwhelmingly used their leader's method, the team reported in the Sept. 29, 2005 Nature.

"To find that some aspects of culture, however rudimentary, can be found in other animals," says study coauthor Frans de Waal, "means our ancestors—maybe even our animal ancestors—had cultural traditions. We know that these cultural traditions were essential to their survival."

But the evolutionary importance of culture might go beyond survival, says van Schaik. He thinks that culture, as a mechanism for transmitting knowledge, played a critical role in hominid cognitive advancement. In fact, cultural interaction in early humans might have catalyzed the heightened intelligence that we possess today, he argues in the April Scientific American.

Van Schaik came to this conclusion after observing a group of wild orangutans in the hot, insect-ridden swamps of Sumatra. Although most orangutans don't use tools in the wild, he says, he found a population of orangutans that fashioned sticks to penetrate the husk of a nourishing but prickly fruit. By contrast, other groups of orangutans that lived nearby risked injury by opening the prickly fruit with their hands or avoided it.

The stick-using orangutans also showed other innovative behaviors that the other groups lacked, and this population was the only one in which adults foraged together.

Van Schaik theorizes that the apes' frequent interactions enabled less-skilled adults to learn an innovative behavior and teach it to their children. Over time, such cultural dissemination advances the overall intelligence of the population, he asserts.

"There seems to be a link between culture and intelligence, in that animals that are more culturally advanced, or have broader cultural repertoires, actually turn out to be smarter," van Schaik says. "That's not terribly surprising if you talk about people, but you don't expect it to be true for nonpeople."

Thus spake Panpanzee

As innovations grew in complexity, the primitive communication techniques used by early apes could have likewise grown. "People speculate why we have language," de Waal says. "One answer could be, it facilitates the transmission of a lot of knowledge."

SAY WHAT? A bonobo named Nyota points to a symbol on a device called a Lexigram. Some apes can communicate with people by pointing to Lexigram symbols, which represent objects or actions, such as chase. www.greatapetrust.org

A new study tackles the evolutionary roots of language by observing the playful behavior of young apes. In people, both language and pretending are considered outgrowths of a general symbolic function, says Patricia Greenfield of the University of California, Los Angeles. If apes develop pretending behavior by advancing through the same stages that children do, Greenfield and her colleagues say, then some shared ancestor probably possessed this general symbolic function.

Human children demonstrate five stages of pretending, the highest being the treatment of toys as animate objects, which shows up after age 2. To study whether apes follow the same path, the researchers analyzed playful interactions between five apes—three bonobos and two chimpanzees—and their caregivers. Most interactions took place when the apes were 2 to 5 years old.

The young apes indeed progressed through the stages of pretend play in the same way that human children do, the researchers report in the July-September Cognitive Development.

The most impressive example of pretending occurred when a female chimp named Panpanzee, then 4 years old, pretended to groom a doll, says study leader Heidi Lyn of the University of St. Andrews in Scotland. Panpanzee then pretended to pluck bugs off her body and feed them to the doll, offering some bugs to the caregiver, Liz, as well. Liz offered some imaginary bugs back to Panpanzee, who pretended to eat them.

Because people, bonobos, and chimpanzees had a common ancestor 5 million years ago, symbolic function—and thus the developmental roots of language—extends back at least this far, the authors conclude.

In the study, the young apes often began pretending on their own and were boosted to a higher level by the responses of their caregivers. The researchers call this process scaffolding. The beginnings of a cognitive skill, such as pretending or using language, might exist without being used for that purpose, but scaffolding puts the mental wheels in motion, Greenfield says.

In a particular environment, the seeds of cognition can mature, she proposes. So, while apes may not naturally use symbolic function for language, they do so in settings where they are trained to communicate through a device called a Lexigram.

Pretend play and Lexigram use may be evidence of a generalized symbolic function out of which language could have grown in the subsequent millions of years, Greenfield says.

Povinelli is more cautious. He worries that when researchers focus on traits shared by ape and human ancestors, they ignore differences between the species that could reveal as much or more about ape and human cognition.

"The danger is that we use our folk psychology to reconstruct the minds of apes according to our own models of human beings," Povinelli says. "We never get at what it's really like to be an ape, and we never fully appreciate what it means to be human."

Without a vast study of many animal species, it's difficult to suggest that any given quality in people emerged from an ancestor shared with apes, says Simon Reader of Utrecht University in the Netherlands, who studies innovative behavior in animals.

"If you only test chimpanzees and find a behavior in common with humans, you still don't know if the behavior is found across primates or the animal kingdom in general," says Reader.

Povinelli would like to see researchers demonstrate that apes consider abstract notions, such as the fundamental difference between colors and shapes. Such experiments have been tried, unsuccessfully, in monkeys, he notes. Discovering the true limits of ape intelligence will show more about humanity, says Povinelli.

"We know that apes can learn to use tools properly," he says. "We've known that for 100 years." The real question is whether ape behavior is the result of abstract considerations—perhaps about the future, the past, or love—or simply a reaction to a situation.

"Yes, they're thinking," says Povinelli. "But what are they thinking about?"

Source: ScienceNews
http://www.sciencenews.org/articles/20060902/bob10.asp

Posted by
Robert Karl Stonjek

New Growth In Old Eyes

A Serving Of Exercise After That Saturated Fat

Devaluing the Race Card

By Yudhijit Bhattacharjee
ScienceNOW Daily News
31 August 2006

Geoffrey Cohen, a psychologist at the University of Colorado, Boulder, and his colleagues tested the strategy among 243 seventh graders at a northeastern U.S. school that had a roughly 50:50 ratio of African-American and white students. Each student was asked to complete a 15-minute writing assignment that included a page with a list of values such as one's relationships with friends, athletic ability, and creativity. Students circled their top two or three values. On the next page, they wrote a few sentences explaining their choices and describing moments when they had felt the importance of the chosen values. The researchers designed a similar assignment for a control group in which students had to circle the value they thought was least important to them and explain why that value could be important to other people. The students were not told the purpose of the assignment.

At the end of the term, the researchers found that African-American students in the treatment group got significantly better grades than same-race students in the control group. Low-performing African Americans seemed to have benefited the most. The assignment didn't have any effect on white students. Overall, the intervention closed the racial achievement gap by 40%, the team reports tomorrow in Science. "The results exceeded our expectations," says Cohen. "It was remarkable."

To find out how the treatment worked, the researchers had the students complete 34 word fragments, seven of which--such as _ACE--could be completed to form either a stereotype-relevant word such as RACE or a stereotype-irrelevant word such as FACE. African-American students who got the intervention formed fewer stereotype-relevant words than did African Americans in the control group. This suggests that the intervention allowed students to distance themselves from racial stereotypes, Cohen says.

The researchers also found that African Americans in the control group did progressively worse as the academic term went on, while those in the treatment group stabilized or started improving after the intervention. "There is something about the stereotype threat that feeds off its consequence: You are stressed that you'll do badly, and so you do; then you get even more stressed and do even worse," Cohen explains. "Our intervention seems to halt this downward spiral."

"These are very exciting results," says Claude Steele, a psychologist at Stanford University in Palo Alto, California, who was among the first to show that the threat of reinforcing negative stereotypes can impair performance among minority students. "They suggest some powerful and simple ways of fixing things in American education." Cohen warns, however, against viewing the intervention as a silver bullet for improving minority-student performance. "It worked in this particular school," he says. "Whether it'll work in a predominantly minority school or at a different grade level, we can't say."

Source: Science
http://sciencenow.sciencemag.org/cgi/content/full/2006/831/2?etoc

Posted by
Robert Karl Stonjek

Populous power.
A cross section of human cortex shows the distribution of a protein fragment (red) that may have been key to human brain evolution.

Credit: James Sikela

Human Evolution: The More the Merrier

By Elizabeth Pennisi
ScienceNOW Daily News
31 August 2006

Evolution occurs when genes mutate, or when they alter where, when, and how strongly they are active. In addition, hiccups in DNA replication can foster change by causing some parts of genes to be repeated as they are copied. Twin genes or duplicated regulatory regions result, and although one in the pair usually has to keep doing its original job, the other is free to mutate and take on new roles that can enhance an organism's survival.

In earlier work, James Sikela, a genome researcher at the University of Colorado, Denver, and Jonathan Pollack from Stanford University and colleagues found 134 genes that had been duplicated primarily after human ancestors split off from other primates. In the new study, Sikela, Gerald Wyckoff from the University of Missouri, Kansas City, and their colleagues compared the sequences of these genes in primates, as well from mice and rats, to reconstruct the history of each duplicated gene.

They found 44 genes with more than five copies each in the human genome. One in particular, called MGC8902, caught their eye. Humans have 49 copies of this gene, while chimps have 10 and macaques have four, the team reports tomorrow in Science. With so many copies, "MGC8902 stands out as a very good candidate to be important to a human specific trait," says Sikela. A closer look revealed that the heavily-duplicated gene contained its own duplications: six copies of a domain called DUF1220.

The domains exist in other primates, but are most common in humans, says Sikela. The researchers discovered that the genes with the DUF1220 domains are expressed in the heart, spleen, skeletal muscle, and small intestine, and are particularly active in the brain's neocortex. Thus, they may play a role in higher cognition.

"The exciting thing here is the expansion of a gene family associated with expression in specific neurons," says Evan Eichler, a geneticist at the University of Washington, Seattle. But, he adds, "I would be cautious about overextrapolating these observations to brain enlargement."

Source: Science
http://sciencenow.sciencemag.org/cgi/content/full/2006/831/4?etoc

Posted by
Robert Karl Stonjek

Model Of Internal Clocks Reveals How Jet Lag Disrupts The System

Irwin Silverman wrote:

> "Believer" is generally associated with
> belief in unsupported notions - e.g.
> You wouldn't call someone a believer in
> gravity or medicine - you would for
> scientology or past lives (fanatics,
> however, may use the term for evolution).

I'm afraid that makes me a fanatic.

What word do you suggest we use for "thinking something is true" if
not 'belief'?

To take an example, Darwin thought that species evolve through the
process of natural selection. Most of us on the list think that too.
In other words, we are committed to the truth of the sentence 'species
evolve through the process of natural selection'. Creationists think
that sentence is false.

In other words, we believe it, but they don't.

Jeremy