Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The mind's eye scans like a spotlight

14.08.2009
New role discovered for brain waves

You're meeting a friend in a crowded cafeteria. Do your eyes scan the room like a roving spotlight, moving from face to face, or do you take in the whole scene, hoping that your friend's face will pop out at you? And what, for that matter, determines how fast you can scan the room?

Researchers at MIT's Picower Institute for Learning and Memory say you are more likely to scan the room, jumping from face to face as you search for your friend. In addition, the timing of these jumps appears to be determined by waves of activity in the brain that act as a clock. The study, which appears in the Aug. 13 issue of the journal Neuron, sheds new light on a long-standing debate among neuroscientists over how the visual system picks out an object of interest in a complex scene.

In the study, monkeys were given the task of searching for one particular tilted, colored bar among a field of bars on a computer screen. By monitoring the activity of neurons in three of the animals' brain regions, researchers found that the monkeys spontaneously shifted their attention in a sequence, like a moving spotlight that jumped from location to location.

What's more, the study showed that brain waves act as a kind of built-in clock that provides a framework for shifting attention from one location to the next. The work could have implications for understanding or treating attention deficit disorder or even potentially speeding up the rate of cognition in the brain.

"For many years, neuroscientists have been debating competing theories on whether humans and animals spontaneously search elements of a visual scene in a serial or parallel manner," said lead author Earl K. Miller, the Picower Professor of Neuroscience. "Ours is the first study based on direct evidence of neurophysiological activity."

Like clockwork

Activity in the brain comes and goes in waves, cycling between high and low activity states. Researchers have been recording brain waves for more than 100 years and although they think they play roles in working memory, decision-making and communication among brain regions, no one is sure of their exact role in brain function. This work suggests a new role for brain waves — one in which they are directly involved in the brain's processing.

Picower Institute postdoctoral associate and co-author Timothy J. Buschman found that the spotlight of the mind's eye shifted focus at 25 times a second and that this process of switching was regulated by brain waves. "This is one of the first examples of how brain waves play a specific role in cognitive computations," Buschman said.

"Attention regulates the flood of sensory information pouring into the brain into a manageable stream. In particular, a lot of different areas of the brain are involved in vision. If they all competed at once, it would be chaos," Miller said. "Brain waves may provide the clock that tells the brain when to shift its attention from one stimulus to another. Oscillating brain waves may provide a way for several regions across the brain to be on the same page at the same time — very similar to the way computers use an internal clock to synchronize the many different components inside."

The researchers' next step is to expand their search for brain wave function beyond the visual. They hope to discover whether brain waves are specific to visual function or act as a "general clock" for the brain.

The researchers have found that in the experiment with the monkeys, the speed at which the animals searched was related to the speed of their brain waves. When the clock ticked faster, the animals "thought" faster. This implies that it may be possible to change the speed of cognition if researchers can learn to artificially manipulate brain waves. In separate studies outside MIT, researchers are looking at the correlation between the brain waves' "clock speed" in humans and the speed at which subjects shift attention from one task to another.

This work is supported by the National Science Foundation and the National Institute of Neurological Disorders and Stroke.

Jen Hirsch | EurekAlert!
Further information:
http://www.mit.edu

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>