Explaining the origins of word order using information theory

The majority of languages — roughly 85 percent of them — can be sorted into two categories: those, like English, in which the basic sentence form is subject-verb-object (“the girl kicks the ball”), and those, like Japanese, in which the basic sentence form is subject-object-verb (“the girl the ball kicks”).

The reason for the difference has remained somewhat mysterious, but researchers from MIT’s Department of Brain and Cognitive Sciences now believe that they can account for it using concepts borrowed from information theory, the discipline, invented almost singlehandedly by longtime MIT professor Claude Shannon, that led to the digital revolution in communications. The researchers will present their hypothesis in an upcoming issue of the journal Psychological Science.

Shannon was largely concerned with faithful communication in the presence of “noise” — any external influence that can corrupt a message on its way from sender to receiver. Ted Gibson, a professor of cognitive sciences at MIT and corresponding author on the new paper, argues that human speech is an example of what Shannon called a “noisy channel.”

“If I’m getting an idea across to you, there’s noise in what I’m saying,” Gibson says. “I may not say what I mean — I pick up the wrong word, or whatever. Even if I say something right, you may hear the wrong thing. And then there’s ambient stuff in between on the signal, which can screw us up. It’s a real problem.” In their paper, the MIT researchers argue that languages develop the word order rules they do in order to minimize the risk of miscommunication across a noisy channel.

[E. Gibson, S.T. Piantadosi, K. Brink, L. Bergen, E. Lim, and R. Saxe. A noisy-channel account of crosslinguistic word order variation. Psychological Science, accepted, 2012]

Worldwide patent for a Spanish stroke rehabilitation robot

Robotherapist 3D, a robot which aids stroke patients’ recovery, is to be brought to market by its worldwide patent holder, a spin-off company from the Miguel Hernández University of Elche (Alicante, Spain). It is the first robot to enable patients to start doing exercises while supine, allowing them to begin shortly after the stroke and expediting recovery.

The company, a leader in this field in Spain, already has two robots: Robotherapist 2D and Robotherapist 3D. For the latter, it has a worldwide patent. Both are actuated by pneumatic technology and have been designed to improve arm movement in stroke patients.

According to the researcher, Robotherapist 2D is a planar robot which allows movement in two dimensions and includes sensors to determine the patient’s condition and a sound feedback system. “With this robot, certain tasks are carried out. The patient’s arm is moved parallel to the table: to the right, to the left and in a straight line. They are exercises to improve coordination,” he says.

A wireless low-power, high-quality EEG headset

Imec, Holst Centre and Panasonic have developed a new prototype of a wireless EEG (electroencephalogram, or brain waves) headset designed to be a reliable, high-quality and wearable EEG monitoring system.

The system combines ease-of-use with ultra-low power electronics. Continuous impedance monitoring and the use of active electrodes increases the quality of EEG signal recording compared to former versions of the system.

How it works

The EEG data is transmitted to a receiver located up to 10 meters away. The headset integrates active electrodes (reduce the susceptibility of the system to power-line interference and cable motion artifacts to improve signal quality), EEG amplifier, microcontroller, and low-power wireless transmitter.

The receiver can continuously record 8-channel EEG signals while concurrently recording electrode-tissue contact impedance (ETI), a measure of contact quality.

The system has a high  (>92 dB) common-mode rejection ratio (to reduce interference from power lines and other sources) and low noise (<6 µVpp, 0.5-100Hz), with configurable cut-off frequency (to filter out high or low frequencies).

The heart of the system is the low-power (750µW) 8-channel EEG monitoring chipset. Each EEG channel consists of two active electrodes and a low-power analog signal processor. The EEG channels are designed to extract high-quality EEG signals under a large amount of common-mode interference. The active electrode chips have buffer functionality with high input impedance (1.4GΩ at 10Hz), enabling recordings from dry electrodes, and low output impedance reducing the power-line interference without using shielded wires

The system is integrated into imec’s EEG headset with dry electrodes, which enables EEG recordings with minimal set-up time. The small size of the electronics system, measuring only 35mm x 30mm x 5mm (excluding battery), allows easy integration in any other product.

Singing Mice Show Signs of Learning

Guys who imitate Luciano Pavarotti or Justin Bieber to get the girls aren’t alone. Male mice may do a similar trick, matching the pitch of other males’ ultrasonic serenades. The mice also have certain brain features, somewhat similar to humans and song-learning birds, which they may use to change their sounds, according to a new study.

"We are claiming that mice have limited versions of the brain and behavior traits for vocal learning that are found in humans for learning speech and in birds for learning song," said Duke neurobiologist Erich Jarvis, who oversaw the study. The results appear Oct. 10 in PLOS ONE and are further described in a review article in Brain and Language.
[Arriaga, G. et. al. (2012) “Mouse vocal communication system: are ultrasounds learned or innate?”  Brain and Language]

The discovery contradicts scientists’ 60-year-old assumption that mice do not have vocal learning traits at all. “If we’re not wrong, these findings will be a big boost to scientists studying diseases like autism and anxiety disorders,” said Jarvis, who is a Howard Hughes Medical Institute investigator. “The researchers who use mouse models of the vocal communication effects of these diseases will finally know the brain system that controls the mice’s vocalizations.”

Human neural stem cells study offers new hope for children with fatal brain diseases

New findings demonstrate potential to treat a wide variety of disorders that affect myelin

Physician-scientists at Oregon Health & Science University Doernbecher Children’s Hospital have demonstrated for the first time that banked human neural stem cells — HuCNS-SCs, a proprietary product of StemCells Inc. — can survive and make functional myelin in mice with severe symptoms of myelin loss. Myelin is the critical fatty insulation, or sheath, surrounding new nerve fibers and is essential for normal brain function.

This is a very important finding in terms of advancing stem cell therapy to patients, the investigators report, because in most cases, patients are not diagnosed with a myelin disease until they begin to show symptoms. The research is published online in the journal Science Translational Medicine.

Myelin disorders are a common, extremely disabling, often fatal type of brain disease found in children and adults. They include cerebral palsy in children born prematurely as well as multiple sclerosis, among others.

Using advanced MRI technology, researchers at OHSU Doernbecher Children’s Hospital also recently recognized the importance of healthy brain white matter at all stages of life and showed that a major part of memory decline in aging occurs due to widespread changes in the white matter, which results in damaged myelin and progressive senility (Annals of Neurology, September 2011).

Stony Brook Researchers Develop Neuroimaging Technique Capturing Cocaine’s Devastating Effect on Brain Blood Flow

Researchers from the Department of Biomedical Engineering at Stony Brook University have developed a high-resolution, 3D optical Doppler imaging tomography technique that captures the effects of cocaine restricting the blood supply in vessels – including small capillaries – of the brain. The study, reported in Molecular Psychiatry, and with images on the journal’s October 2012 cover, illustrates the first use of the novel neuroimaging technique and provides evidence of cocaine-induced cerebral microischemia, which can cause stroke.

In “Cocaine-induced cortical microischemia in the rodent brain: clinical implications,” the researchers discovered that cocaine administered in doses equivalent to those normally taken by abusers caused constriction in blood vessels that inhibited CBF for varying lengths of time. Brain arteries, veins, and even capillaries, the smallest vessels, were affected by the doses. CBF was markedly decreased within just two-to-three minutes after drug administration. In some vessels, a decrease in CBF reached 70 percent. Recovery time for the vessels varied. Cocaine interrupted CBF in some arteriolar branches for more than 45 minutes. This effect became more pronounced after repeated cocaine administration.

“Our study revealed evidence of cocaine-induced cerebral microischemic changes in multiple experimental models, and we were able to clearly image the process and vasoactive effects at a microvascular level,” said study Principal Investigator Yingtian Pan, PhD, Professor, Department of Biomedical Engineering, Stony Brook University. “These clinical changes jeopardize oxygen delivery to cerebral tissue making it vulnerable to ischemia and neuronal death.”

What Drives Your Daily Biological Clock?

Researchers working with fruit flies say they have discovered one way that the body’s biological clock controls brain-cell activity that influences daily rhythms.

They believe their findings might improve understanding about sleep-wake cycles and lead to new treatments for sleep disorders and jet lag.

"The findings answer a significant question: how biological clocks drive the activity of clock neurons, which, in turn, regulate behavioral rhythms," study senior author Justin Blau, associate professor in New York University’s department of biology, said in a university news release.

Previous research with fruit flies’ “clock genes” led to the discovery of similar genes in humans, according to the news release.

It was known that biological clocks control neuronal activity, but it wasn’t known how information from biological clocks drives rhythms in the electrical activity of pacemaker neurons that control daily rhythms.

The NYU team looked at pacemaker neurons in the central brain of fruit flies that set the timing of the daily transitions between sleep and wake. They isolated these neurons and identified sets of genes with different levels of activity at dawn and dusk.

Follow-up experiments found that the activity of a gene called Ir was much higher at dusk than at dawn and that it was more active in the pacemaker neurons than in the rest of the brain. The researchers also found that increasing or decreasing levels of Ir affected behavioral rhythms and changed the timing and strength of variations in the core clock.

"We were looking for an output of the biological clock that would link the core clock to neuronal activity," Blau said. "Ir seems to do this, but it also, remarkably, feeds back to regulate the core clock itself. Feedback loops seem to be deeply engrained into the biological clock and presumably help these clocks work so well."

The study was published in the October issue of the Journal of Biological Rhythms. Researchers have noted that results from animal studies do not necessarily translate to humans.