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