The Brains Of Deaf People Process Touch Differently 

 People who are born deaf process the sense of touch differently than people who are born with normal hearing, according to research funded by the National Institutes of Health. The finding reveals how the early loss of a sense - in this case hearing - affects brain development. It adds to a growing list of discoveries that confirm the impact of experiences and outside influences in molding the developing brain. The study is published in the July 11 online issue of The Journal of Neuroscience.

 The researchers, Christina M. Karns, Ph.D., a postdoctoral research associate in the Brain Development Lab at the University of Oregon, Eugene, and her colleagues, show that deaf people use the auditory cortex to process touch stimuli and visual stimuli to a much greater degree than occurs in hearing people. The finding suggests that since the developing auditory cortex of profoundly deaf people is not exposed to sound stimuli, it adapts and takes on additional sensory processing tasks.

 "This research shows how the brain is capable of rewiring in dramatic ways," said James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. "This will be of great interest to other researchers who are studying multisensory processing in the brain."

 Previous research, including studies performed by the lab director, Helen Neville Ph.D., has shown that people who are born deaf are better at processing peripheral vision and motion. Deaf people may process vision using many different brain regions, especially auditory areas, including the primary auditory cortex. However, no one has tackled whether vision and touch together are processed differently in deaf people, primarily because in experimental settings, it is more difficult to produce the kind of precise tactile stimuli needed to answer this question.

 Dr. Karns and her colleagues developed a unique apparatus that could be worn like headphones while subjects were in a magnetic resonance imaging (MRI) scanner. Flexible tubing, connected to a compressor in another room, delivered soundless puffs of air above the right eyebrow and to the cheek below the right eye. Visual stimuli - brief pulses of light - were delivered through fiber optic cables mounted directly below the air-puff nozzle. Functional MRI was used to measure reactions to the stimuli in Heschl's gyrus, the site of the primary auditory cortex in the human brain's temporal lobe as well as other brain areas.

 The researchers took advantage of an already known perceptual illusion in hearing people known as the auditory induced double flash, in which a single flash of light paired with two or more brief auditory events is perceived as multiple flashes of light. In their experiment, the researchers used a double puff of air as a tactile stimulus to replace the auditory stimulus, but kept the single flash of light. Subjects were also exposed to tactile stimuli and light stimuli separately and time-periods without stimuli to establish a baseline for brain activity. Hearing people exposed to two puffs of air and one flash of light claimed only to see a single flash. However, when exposed to the same mix of stimuli, the subjects who were deaf saw two flashes. Looking at the brain scans of those who saw the double flash, the scientists observed much greater activity in Heschl's gyrus, although not all deaf brains responded to the same degree. The deaf individuals with the highest levels of activity in the primary auditory cortex in response to touch also had the strongest response to the illusion. 

"We designed this study because we thought that touch and vision might have stronger interactions in the auditory cortices of deaf people," said Dr. Karns." As it turns out, the primary auditory cortex in people who are profoundly deaf focuses on touch, even more than vision, in our experiment."

  There are several ways the finding may help deaf people. For example, if touch and vision interact more in the deaf, touch could be used to help deaf students learn math or reading. The finding also has the potential to help clinicians improve the quality of hearing after cochlear implants, especially among congenitally deaf children who are implanted after the ages of 3 or 4. These children, who have lacked auditory input since birth, may struggle with comprehension and speech because their auditory cortex has taken on the processing of other senses, such as touch and vision. These changes may make it more challenging for the auditory cortex to recover auditory processing function after cochlear implantation. Being able to measure how much the auditory cortex has been taken over by other sensory processing could offer doctors insights into the kinds of intervention programs that would help the brain retrain and devote more capacity to auditory processing.

Becoming a Consumer of Psychology

By Kendra Cherry

Whether you realize it or not, you’ve probably been a consumer of psychology at some point. Nearly every day, new reports about the findings of the latest psychology studies are broadcast on television, printed in newspapers or sensationalized on talk shows. Just pick up any popular magazine to see any number of self-help articles that synthesize current psychology research.

How can you determine if these reports are credible or not? In order to become a wise consumer of psychology research, you need to learn how to evaluate the various research reports you come into contact with each day. By understanding how to identify trustworthy information, you can become an informed psychology consumer.

1. Consider the Source:

Whenever you read the results of psychology research in popular media sources, you should always consider the original source of the information. Studies published in professional psychology journals have gone through a rigorous examination process, starting with the original study conducted by a reputable researcher and generally backed by a educational institution, hospital or other organization. These journals are also peer-reviewed, which means that other psychologists skilled in research methods and statistics have investigated the research prior to publication.

Another reason to look at the original source is that many popular reports misinterpret or fail to explain key elements of the findings. Writers and journalists who are have no experience in research methods may not fully understand how the study was conducted and all of the possible implications of the research. By looking at the study yourself, you can gain a fuller and richer understanding of what the findings mean.

2. Be Skeptical of Sensational or Shocking Claims:

When evaluating any type of scientific information, skepticism should always be the rule. Be especially wary of claims or findings that seem sensational or unrealistic. Remember that the goals of these popular media reports are to garner attention, sell issues and increase ratings. Reporters may focus on particular elements of a study, while ignoring other important information that is essential for understanding the results. Statements made by researchers may be used out of context in a way that dramatically overstates the original results of the study.

3. Evaluate the Research Methods:

In order to be a wise consumer of psychology, it is important to understand some of the basics of psychology research. Elements such as operational definitions, random sampling and research design are important for understanding the final results of a study. For example, a particular study may only look at specific individuals within a population or it may consider only a narrow definition of a particular topic. Both of these factors can play a role in what the findings mean to the general population and how the results can be applied to understanding psychological phenomena.

4. Remember That Anecdotes Do Not Equal Data:

Be wary of stories or reports that rely solely on anecdotal stories to back up their claims. Just because a small group of individuals have arrived at a similar conclusion does not mean that the population at large shares this view. Scientific research utilizes random sampling and other research methods to help ensure that the results of a study can be generalized to the rest of the population. Any report that relies on a “This is true for me, so it must be true for everyone else” justification should be viewed with skepticism.

5. Consider Who Funded the Research:

In evaluating psychological research, it is also important to consider the financial backers who supported the study. Funding can come from a variety of sources including government agencies, non-profit groups and large corporations.

Be cautious when the results of a study seem to support the agenda of an organization whose goal is to sell products or convince people to share their viewpoint. While such funding sources do not invalidate the results of a study, you should always be on the lookout for potential conflicts of interest.

6. Realize That Correlation Does Not Equal Causation:

Many popular reports of scientific research jump to conclusions and imply causal relationships between variables. A relationship between two variables, however, does not necessarily imply that changes in one cause changes in another. Never assume that there is a cause-and-effect relationship between two factors. Look for key phrases such as "researchers have found a connection", "research indicates a relationship between" and "there appears to be a link" to help identify correlational research.

Newspapers, magazines, books and online sources are full of information about the latest psychological research. In order to determine how trustworthy these reports are, it is important to know how to evaluate the stories you read. While looking up the original study is the best way to assess the information, you can also apply some basic scientific common sense. Be wary of sensationalized claims, watch out for false implications of causation and remember that skepticism is the rule when evaluating any scientific report.

A very helpfull article by 

Kendra Cherry

How nervous systems adapt to extreme environments (It's not always DNA)

For release: Wednesday, May 9, 2012

Auto engines, wind turbines and all manner of machines tend to operate less efficiently in the cold.  Ion channels – the molecular machines that power nerve cell firing and muscle contraction – are no exception.  That poses a challenge for animals that live in icy environments; to survive, they must adapt so that their ion channels can function at temperatures below freezing. In a study published in Science,* researchers have reported how one animal accomplishes this feat.  Their work may shed light on the role of ion channels in human health and disease.

Bathypolypus arcticus. Credit: Sandra Garrett, University of Puerto Rico

The study was conducted by Joshua Rosenthal, Ph.D., an associate professor of neurobiology at the University of Puerto Rico, and Sandra Garrett, a graduate student in his lab.  They chose to look at ion channel variations in different species of octopi, which can live in diverse climates.  At first, they focused on two species, one from the balmy waters of Puerto Rico and another from the frigid seas of Antarctica. The scientists searched for key differences in the animals' "delayed rectifier" potassium channels.  These are gated pores that allow potassium to flow in and out of nerve cells; the flux of potassium is necessary for nerve cells to fire and is especially important for repetitive firing.  Unlike mammals, octopi cannot generate their own body heat.  So, without adjustment for the cold, the potassium channels of octopi in polar climates would be expected to open and close more slowly than their tropical counterparts.  That would in turn alter the rate of nerve cell firing. Because ion channels are proteins, which are made by genes, nature could have solved this problem through genetic mutation.  But Dr. Rosenthal and Ms. Garrett found that the DNA codes for the potassium channels from polar and tropical species are nearly identical.  Instead, they discovered that the channels are modified at the level of RNA, the intermediate chemical between DNA and proteins.

The researchers found that a process called RNA editing produces several small differences between the two channels.  In the polar channel, a change to a single amino acid (the smallest building block for a protein) accelerates the rate at which the channel closes and thus helps compensate for the cold.  This same editing site was found in potassium channels of several other octopus species, including two more tropical species, one from temperate waters, and two from the Arctic.  The extent of editing was higher in species living in colder habitats.

"Species from the Arctic are editing these ion channels in the same manner as the Antarctic species on the opposite side of the world," said Dr. Rosenthal. 

This is the first time that differences in RNA editing have been linked to differences in an animal’s environment – in this case, temperature.  It is not yet known if an octopus can use RNA editing to rapidly adjust to changing temperatures, or if these editing differences evolve slowly over generations.

Beyond implications for how nervous systems adapt to unique environments, the findings could offer deep insights into human ion channels.  Adaptive changes to ion channels, through RNA editing or other means, can point to sites within them that are functionally important across species, Dr. Rosenthal said.  Such knowledge could lead to advances in understanding and treating a number of neurological disorders that have been linked to abnormal ion channel function.  These "channelopathies" include some types of epilepsy and migraine.

Meanwhile, RNA editing has "huge unexplored potential" for human health, Dr. Rosenthal said.  Compared to humans and other vertebrates (animals with a backbone), RNA editing appears to be more extensive in invertebrates (no backbone).  However, every animal species appears to have a set of RNA-editing enzymes known as ADARs, according to Dr. Rosenthal.

With these enzymes, "nature is providing a system that can make genetic changes at the level of RNA.  This may give us a novel approach to gene therapy," he said.

Dr. Rosenthal is investigating the potential of using RNA editing to treat a disorder called rapid-onset dystonia parkinsonism (RDP), which is caused by genetic mutations in a protein called the sodium-potassium pump.  This pump works a bit like a battery, charging up nerve cells so that they can fire.  In invertebrates, the sodium-potassium pump is fine-tuned by RNA editing.  Dr. Rosenthal theorizes that it might be possible to treat RDP by stimulating human RNA-editing enzymes to repair the pump.

Dr. Rosenthal’s research is supported by NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and by the National Science Foundation.  Ms. Garrett is supported by a pre-doctoral fellowship from NINDS.

- By Daniel Stimson, PhD.

*Garrett S and Rosenthal J.  "RNA Editing Underlies Temperature Adaptation in K+ Channels from Polar Octopi."Science, February 17, 2012, Vol. 335, pp. 848-851.

Video: This Amazing Image Filter Lets Doctors See Under Your Skin - The Atlantic

A remarkable new project is capable of magnifying tiny movements in human physiology, like heartbeats, blood flow, and breathing.



It's like a magnifying glass for video: a special image processing filter designed by MIT researchers that lets you see body functions the human eye is too weak to pick up.

From monitoring a baby's breathing to detecting a person's pulse through their skin, the new technology could have far-reaching applications. It's called Eulerian Video Magnification, and it's incredible, reports Talking Points Memo's Carl Franzen:

The system works by selectively amplifying color variation between pixels in the video footage. It can 
also be applied to a still camera if the images are taken shortly after one another, on "burst" mode.
[...]
"After getting it to work for visualizing the human pulse, we then realized we could also amplify motion signals using a very similar technique," the researchers explained. "We noticed motion amplifications in our amplified human pulse signal, so we went back to understand that, and then figured out how to control and exploit it."

The MIT project has a grant from the Pentagon and also enjoys support from the computer graphics giant, Nvidia.

Watch:

Study of the Day: Bilingualism May Boost Attention, Working Memory - The Atlantic

Northwestern University trial provides new biological evidence that dual language speakers have enhanced auditory nervous systems



PROBLEM: Previous research has shown that lifelong musical training improves the biological processing of sound in ways that enhance attention and working memory. Does bilingualism lead to similar benefits?

METHODOLOGY: Northwestern University researchers led by Jennifer Krizman examined the subcortical auditory regions of 23 bilingual English- and Spanish-speaking teenagers and 25 English-speaking teens. To inspect how bilingualism affects the subjects' brain, they recorded brainstem responses as they heard speech sounds in a silent and noisy setting.

RESULTS: The monolingual and bilingual subjects responded similarly in the quiet condition. Against a backdrop of background noise, however, the bilingual brains were better at encoding the fundamental frequency of speech sounds known to underlie pitch perception and grouping of auditory objects, indicating improvements in auditory attention and working memory.

CONCLUSION: Bilingualism yields functional and structural changes in cortical regions of the brain dedicated to language processing and executive function.

IMPLICATION: Dual language speakers are highly efficient in processing auditory information. "Bilinguals are natural jugglers," says co-author Viorica Marian in a statement. "The bilingual juggles linguistic input and, it appears, automatically pays greater attention to relevant versus irrelevant sounds."

SOURCE: The full study, "Subcortical Encoding of Sound Is Enhanced in Bilinguals and Relates to Executive Function Advantages," (PDF) is published in the journal Proceedings of the National Academy of Sciences.