Monthly Archives: November 2007

Bipolar People More Likely to Have Facial Prosopagnosia?

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This, I surmised, from a side-note in a study that otherwise was very interesting in and of itself.

Facial expressions have greater impact on kids with bipolar disorder

Children with bipolar disorder respond differently to facial expressions than children without psychiatric disorders, according to a new study led by a Bradley Hospital researcher. [...]

The study included 23 children with bipolar disorder and 22 typically developing children without psychiatric disorders between the ages of 7 and 17. Dickstein and his team used functional magnetic resonance imaging (MRI), a non-invasive technique that localizes regions of the brain activated during cognition and experience, to scan the children while they “encoded” different facial expressions.

During the MRI scan, the children viewed photos of 32 different actors – eight actors each displaying one of four emotions (angry, fearful, happy and neutral) – from standard gray-scale photograph sets of facial expressions. After seeing the photos four times, they rated each face by answering questions such as “How afraid are you”” “How hostile is the face”” and “How wide is the nose””

Thirty minutes after the MRI scan, children were given a surprise out-of-scanner memory task, during which they viewed 48 actors (half of which were seen previously during the MRI and half that were not previously viewed). They were then asked whether they recalled seeing the face during the earlier test.

During the encoding of “happy” faces, researchers observed increased activity in the region of the brain (striatum) associated with rewards in the children with bipolar disorder. Increased activity was also found in the part of the brain (orbitofrontal cortex) liked to irritability when the same children encoded “angry” faces. Brain activity in both instances was significantly greater than in children without bipolar disorder.

Based on the number of correct identifications during the memory task, Dickstein and colleagues also found that children with bipolar disorder demonstrated reduced memory for emotional faces as compared to children without bipolar disorder – particularly with “fearful” faces. (Source: Eurekalert)

Eurekalert.org’s Pimping Search Function

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I’ve found that eurekalert.org, my favorite place to read science news… actually keeps a huge archive of all of the studies it reports on. So think of almost anything you want to read studies on, type it in their search function and up comes years of awesome research conveniently summarized for you.

So far I’ve found awesome stuff on nearly every keyword I type in. I recommend you guys try it.

Fear The No.2 Pencil, Kids

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For it has been found that, in children lead levels of less than ~100 parts per billion causes cognitive damage, and lowers IQ. This is lower than the amount considered “safe” by the center of disease control.

The study examined the effect of lead exposure on cognitive function in children whose blood-lead levels (BLLs) were below the Centers for Disease Control and Prevention (CDC) standard of 10 micrograms per deciliter (mcg/dl) — about 100 parts per billion. The researchers compared children whose BLLs were between 0 and 5 mcg/dl with children in the 5-10 mcg/dl range.

“Even after taking into consideration family and environmental factors known to affect a child’s cognitive performance, blood lead played a significant role in predicting nonverbal IQ scores,” says Richard Canfield, a senior researcher in Cornell’s Division of Nutritional Sciences and senior author of the study in the journal Environmental Health Perspectives. “We found that the average IQ scores of children with BLLs of only 5 to 10 mcg/dl were about 5 points lower than the IQ scores of children with BLLs less than 5 mcg/dl. This indicates an adverse effect on children who have a BLL substantially below the CDC standard, suggesting the need for more stringent regulations,” he said. (Source: Eurekalert)

Estrogen Keeps Your Dopamine Producing Neurons Alive

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I love my dopamine producing neurons. And yet, I consider myself a manly man at heart. It comes as difficult to accept, then, that estrogen keeps dopamine producing neurons alive. This study was done on females, however…

“Without estrogen, more than 30 percent of all the dopamine neurons disappeared in a major area of the brain that produces the neurotransmitter, dopamine, ” Redmond said. “This finding is consistent with a lot of observations for which there has been, until now, no explanation. The results of the study shed light on why men, who have less estrogen in their bodies and more androgen to antagonize it, are more likely to develop Parkinson’s Disease than pre-menopausal women, and why post menopausal women are more likely then to develop the disease.”

The discovery was made after the researchers removed the ovaries of female monkeys, thereby depleting their bodies of estrogen and other gonadal hormones. Within 10 days, key neurons in the brain that protect against Parkinson’s Disease disappeared. (Source: Eurekalert)

Estrogen is a “gonadal” hormone. Awesome. I get the last laugh, estrogen.

A Little Photoshop Will Change Your Beliefs

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I’m continuously amazed by the human mind’s capacity for self-deception. Our memories are fallible, and because of this we fill in the blanks with approximations that make sense.

Doctored photos of past public events can influence what people think they remember of the incident, as well as altering their attitudes and any subsequent responses, according to research published today in the journal ‘Applied Cognitive Psychology’.

Three researchers (two in Italy and one in the USA) came to this conclusion after showing either original or digitally doctored images to 299 people aged 19-84. The images were of two different protests, one in 1989 in Tiananmen Square, the other 2003 in Rome. After seeing the images, participants were asked questions about the events, without telling them that the research project was interested in the effect that the photo would have on their responses.

They were asked questions about the numbers of people they thought had been involved, the response of law enforcement authorities and the level of violence.

Clear differences in responses came from people who had seen the original and doctored photos.

“One major result was that viewing modified images affected not only the way people remember past public events, but also their attitudes and behavioural intentions,” says Franca Agnoli, from the University of Padova, who supervised the experiments.

For example, people who were influenced to think that the event had been more violent than was the actual case, reported that they were less likely to take part in similar demonstrations in the future.

“Any media that employ digitally doctored photographs will have a stronger effect than merely influencing our opinion – by tampering with our malleable memory, they may ultimately change the way we recall history,” (From: Eurekalert)

Schizophrenics Keep Rupturing Their Appendix(es)

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How bizarre is this… apparently schizophrenics are more likely to have ruptured a supposedly vestigial organ, the appendix.

Tsay and colleagues found that a ruptured appendix occurred in 46.7 percent of the schizophrenic patients, in 43.4 percent of the patients with other major mental disorders, and in 25.1 percent of the patients with no major mental diseases. More ruptured cases were found among males and older patients. (Source: Eurekalert)

It’s interesting to note that the appendix was recently officially declared as “not necessarily vestigial” by the news… It may be used to harbor good intestinal bacteria.

Wiggling Your Eyes Improves Memory Recall

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Moving your eyes from left to right may enhance the ability of the brain to monitor the source of it’s memories by increasing hemispheric interaction.

Horizontal eye movements are thought to cause the two hemispheres of the brain to interact more with one another, and communication between brain hemispheres is important for retrieving certain types of memories. [...] The researchers found that the people who performed the horizontal eye movements correctly remembered, on average, more than 10 percent more words, and falsely recognized about 15 percent fewer “lure” words than the people who performed vertical eye movements or no movements at all. (Source: Livescience)

I like research like this because it tells me things about the human mind that I can see, and read on the faces of other people.

Does Your Mom Have Alzheimer’s?

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If she does, you’re more likely to get Alzheimer’s than if your dad was to have it.

Over the last two decades a number of studies have shown that people with the disease have significant reductions in brain energy metabolism in certain regions of the brain. In some recent research studies these reductions are evident in healthy people years before symptoms of dementia emerge.

The researchers wanted to evaluate people with a family history of Alzheimer’s because that is one of the biggest risk factors for the disease. Alzheimer’s affects more than 5 million Americans and is the most common form of senile dementia. People with an affected parent have a 4- to 10-fold higher risk compared to individuals with no family history. It isn’t known why people with a family history are more susceptible to the disease.

Likewise, it isn’t known why individuals with a history of the disease on their mother’s side are at increased risk for Alzheimer’s, and this observation must be replicated in larger studies before it could be of use in the clinic to perhaps identify people who may be more vulnerable to the disease, says Lisa Mosconi, Ph.D., Research Assistant Professor of Psychiatry at NYU School of Medicine, who led the new study. She speculates that genes that are maternally inherited might alter brain metabolism.

The new study involved 49 cognitively normal individuals, from 50 to 80 years old, who underwent a battery of neuropsychological and clinical tests, and PET (positron emission tomography) scans of their brains using a technique that labels glucose—the brain’s fuel—with a special chemical tracer. Sixteen subjects had a mother with the disease, and eight had a father with Alzheimer’s. The remaining subjects didn’t have a family history of the disease.

People with a maternal history of the disease had the largest reductions in glucose metabolism in several areas of the brain, including the medial temporal lobes and the posterior cingulate cortex, two brain regions involved with memory storage and retrieval. Brain energy metabolism was reduced by 25 percent in the posterior cingulate cortex in this group

There weren’t any reductions in brain energy metabolism in the people without a family history and in those with a father who had the disease. The effects in glucose metabolism among subjects with a maternal history remained significant after accounting for possible risk factors for Alzheimer’s, including age, gender, education, Apolipoprotein E genotype, and subjective memory complaints.

There was NO link to reduced glucose metabolism when the father had the disease. The link to mothers and Alzheimer’s appears to be quite strong. This may turn out to be a lot more than a mundane detail when interpreting future research.