Dyslexia brain communication breakdown

 

 

Dyslexic people have trouble linking written symbols with corresponding speech sounds.

 

Dyslexia linked to brain communication breakdown

Dyslexia linked to brain communication breakdown

Dyslexia may be caused by impaired connections between auditory and speech centres of the brain, according to a study published today in Science1. The research could help to resolve conflicting theories about the root causes of the disorder, and lead to targeted interventions.

When people learn to read, their brains make connections between written symbols and components of spoken words. But people with dyslexia seem to have difficulty identifying and manipulating the speech sounds to be linked to written symbols. Researchers have long debated whether the underlying representations of these sounds are disrupted in the dyslexic brain, or whether they are intact but language-processing centres are simply unable to access them properly.

A team led by Bart Boets, a clinical psychologist at the Catholic University of Leuven in Belgium, analysed brain scans and found that phonetic representations of language remain intact in adults with dyslexia, but may be less accessible than in controls because of deficits in brain connectivity.

“The authors took a really inventive and thoughtful approach,” says John Gabrieli, a neuroscientist at the Massachusetts Institute of Technology in Cambridge, Massachusetts. “They got a pretty clear answer.”

Communication channels

Boets and his team used a technique called multivoxel pattern analysis to study fine-scale brain signals as people listened to a battery of linguistic fragments such as ‘ba’ and ‘da’. To the researchers’ surprise, neural activity in the primary and secondary auditory cortices of participants with dyslexia showed consistently distinct signals for different sounds.

But images of dyslexic people’s brains revealed reduced structural integrity of the white-matter tracts linking the auditory cortices and the left inferior frontal gyrus — a brain area involved in language processing, including speech production. Even when the study participants were not doing any tasks, activity in these areas was less correlated in the brains of the dyslexic people than in the controls, suggesting that they had weaker communication between their auditory and speech centres.

Together, these findings suggest that dyslexic people do not have distorted neural representations of speech sounds; rather, “the problem seems to be in pathways down the road that help us assemble those sounds and produce those sounds when we read out loud”, explains Guinevere Eden, a neuroscientist at Georgetown University in Washington DC.

Boets cautions that studying adults can reveal only the end result of atypical development; dyslexic people could have distorted phonetic representations early in life. But, he says, the results argue that weakened connections between specific brain regions have an important role. Ultimately, Boets hopes that the insights could lead to improvements to treatments and exercises for dyslexia, which historically have focused on strengthening phonetic representations.

“It should be possible to design strategies to specifically improve the connections,” says Boets.

Synthetic gel communicates with itself

In a paper published in the January 8 print edition of the Proceedings of the National Academy of Sciences, the research team demonstrates that a synthetic system can reconfigure itself through a combination of chemical communication and interaction with light.

This study demonstrates the ability of a synthetic material to actually 'talk to itself'

This study demonstrates the ability of a synthetic material to actually ‘talk to itself’

Anna Balazs, principal investigator of the study and professor of chemical and petroleum engineering in the University of Pittsburgh’s Swanson School of Engineering, has long studied the properties of the Belousov-Zhabotinsky (BZ) gel, a material first fabricated in the late 1990s and shown to pulsate in the absence of any external stimuli.

In a previous study, the team noticed that long pieces of gel attached to a surface by one end “bent” toward one another, almost as if they were trying to communicate by sending signals. This hint that “chatter” might be taking place led the team to detach the fixed ends of the gels and allow them to move freely.

Balazs and her team developed a 3D gel model to test the effects of the chemical signaling and light on the material. They found that when the gel pieces were moved far apart, they would automatically come back together, exhibiting autochemotaxis—the ability to both emit and sense a chemical, and move in response to that signal.

“This study demonstrates the ability of a synthetic material to actually ‘talk to itself’ and follow out a given action or command, similar to such biological species as amoeba and termites,” says Balazs.

“Imagine a Lego set that could by itself unsnap its parts and then put itself back together again in different shapes but also allow you to control those shapes through chemical reaction and light.”

“We find this system to be extremely exciting and important because it provides a unique opportunity to study autochemotaxis in synthetic systems,” says Olga Kuksenok, a member of the research team and research associate professor in the department of chemical engineering.

The National Science Foundation, Army Research Office, and Air Force Office of Scientific Research supported the research.

Scientists might be overlooking alien communication

Scientists suggest we might be overlooking alien communications:

Scientists suggest we might be overlooking alien communications

Scientists suggest we might be overlooking alien communications

A new theory has been put forward in the astrophysics world suggesting people have assumed too much when looking for alien attempts to communicate with Earth.

The theory, proposed by James Benford, his son, Dominic Benford, and Jame’s twin brother Gregory Benford, published in two papers in June, have generated a great deal of excitement in the science world. The Benfords looked at the issue of communications and concluded that aliens, much like humans, would want to economize their resources where possible, and thus they would not send out communications resembling what scientists have expected would be sent. Instead, the scientists suggest, aliens might be as frugal with expensive resources as humans are. The University of California Irvinesaid extraterrestrials might have been trying to contact Earth all along, but because scientists were looking for something different, the messages were missed. The trio of scientists believe extraterrestrials might send out short messages, or pulses. James explained, saying

“This approach is more like Twitter and less like War and Peace.”

James is a physicist as well as the founder and president of Microwave Sciences Inc. in Lafayette, California. Dominic is a scientist with NASA, and Gregory is an astrophysicist with the University of California Irvine. The new hypothesis is based on an old adage. Gregory explained

“Our grandfather used to say, ‘Talk is cheap, but whiskey costs money.’ Whatever the life form, evolution selects for economy of resources. Broadcasting is expensive, and transmitting signals across light-years would require considerable resources.”

SETI(Search for Extraterrestrial Intelligence) has been searching for extraterrestrials for the past fifty years, trolling for signals from space with arrays of satellite dishes. The Benfords hypothesize

“Assuming that an alien civilization would strive to optimize costs, limit waste and make its signaling technology more efficient, … these signals would not be continuously blasted out in all directions but rather would be pulsed, narrowly directed and broadband in the 1-to-10-gigahertz range.”

James summarized their hypotheses and findings during an interview with New Scientist.

“If ET was building cost-effective beacons, would our searches have detected them? The answer turns out to be no. Societies are always constrained by their resources. Why did cathedrals take centuries to build? Partly because they had only so many artisans, but also their capital was limited.”

James explained the hypothesis to the New Scientist

“Short pulses rather than a continuous signal would also enable frugal aliens to use small and cheap transmitters. Small transmitters can beam out powerful radiation using high voltages – but only if they broadcast brief pulses that don’t give the electric fields time to discharge. They wouldn’t want to target individual stars: there are far too many of them. Instead, they’d build a powerful beacon, then swing that beacon around and repeat it. Astronomers have seen some unexplained signals that lasted for tens of seconds then were never seen again. Some of those could have been extraterrestrial beacons but there wasn’t enough observing time to wait for any repeats.”

The Benfords suggest SETI should point its receiver dishes towards the center of the milky way because the stars are denser there. Gregory said

“The stars there are a billion years older than our sun, which suggests a greater possibility of contact with an advanced civilization than does pointing SETI receivers outward to the newer and less crowded edge of our galaxy.”

The short pulse approach to communications has cottoned on quickly, with science writers calling the theory Benford beacons. The hypothesis has also meant that many are speculating that the WOW signal, found in 1977, might actually be an alien tweet. The signal was dismissed as a ‘cosmic burp.’ Gregory said

“Will searching for distant messages work? Is there intelligent life out there? The SETI effort is worth continuing, but our common-sense beacons approach seems more likely to answer those questions.”

The real answer, of course, will be revealed as scientists test the hypothesis. The Benford’s theory has been endorsed by other scientists. The trio’s hypotheses were written up in two papers, Searching for Cost-Optimized Interstellar Beaconsand Messaging with Cost-Optimized Interstellar Beacons, both of which were published in Astrobiology in June.