Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Princeton study reveals the brain's mysterious switchboard operator

20.08.2012
A mysterious region deep in the human brain could be where we sort through the onslaught of stimuli from the outside world and focus on the information most important to our behavior and survival, Princeton University researchers have found.

The researchers report in the journal Science that an area of our brain called the pulvinar regulates communication between clusters of brain cells as our brain focuses on the people and objects that need our attention.

Like a switchboard operator, the pulvinar makes sure that separate areas of the visual cortex — which processes visual information — are communicating about the same external information, explained lead author Yuri Saalmann, an associate research scholar in the Princeton Neuroscience Institute (PNI). Without guidance from the pulvinar, an important observation such as an oncoming bus as one is crossing the street could get lost in a jumble of other stimuli.

Saalmann said these findings on how the brain transmits information could lead to new ways of understanding and treating attention-related disorders, such as attention deficit hyperactivity disorder (ADHD) and schizophrenia. Saalmann worked with senior researcher Sabine Kastner, a professor in the Department of Psychology and the Princeton Neuroscience Institute; and PNI researchers Xin Li, a research assistant; Mark Pinsk, a professional specialist; and Liang Wang, a postdoctoral research associate.

The researchers developed a new technique to trace direct communication between clusters of neurons in the visual cortex and the pulvinar. The team produced neural connection maps using magnetic resonance imaging (MRI), then placed electrodes along those identified communication paths to monitor brain signals of macaques. The researchers trained the monkeys to play a video game during which they used visual cues to find a specific shape surrounded by distracting information. As the macaques focused, Saalmann and his colleagues could see that the pulvinar controlled which parts of the visual cortex sent and received signals.

Saalmann explains the Princeton findings as follows:

"A fundamental problem for the brain is that there is too much information in our natural environment for it to be processed in detail at the same time. The brain instead selectively focuses on, or attends to, the people and objects most relevant to our behavior at the time and filters out the rest. For instance, as we cross a busy city street, our brain blocks out the bustle of the crowd behind us to concentrate more on an oncoming bus.

"The transmission of behaviorally relevant information between various parts of the brain is tightly synchronized. As one brain area sends a signal about our environment, such as that a bus is approaching, another brain area is ready to receive it and respond, such as by having us cross the street faster. A persistent question in neuroscience, though, is how exactly do different brain areas synchronize so that important information isn't lost in the other stimuli flooding our brains.

"Our study suggests that a mysterious area in the center of the brain called the pulvinar acts as a switchboard operator between areas on the brain's surface known as the visual cortex, which processes visual information. When we pay attention to important visual information, the pulvinar makes sure that information passing between clusters of neurons is consistent and relevant to our behavior.

"These results could advance the understanding of the neural mechanisms of selective attention and how the brain transmits information. This is a necessary step in developing effective treatment strategies for medical disorders characterized by a failure of attention mechanisms. These conditions include ADHD, schizophrenia and spatial neglect, which is an inability to detect stimuli often observed following stroke.

"For our study, we trained monkeys to play a video game in which they paid attention to visual cues in order to detect different target shapes. We simultaneously recorded brain activity in the pulvinar and two different areas of the visual cortex. We could see a clear connective path from one portion of the cortex to another, as well as connective paths from the pulvinar to the cortex. When the monkeys paid attention to the visual cues, the pulvinar sent electrical pulses to synchronize particular groups of brain cells in the visual cortex to allow them to communicate effectively.

"A challenge in this study was that we needed to record the activity of cells that were 'speaking' directly with each other so we could trace the line of communication. But there are billions of brain cells. Traditionally, finding a cell-to-cell connection is as likely as randomly selecting two people talking on cell phones in different parts of New York City and discovering that they were speaking to each other.

"To 'listen in' on a direct cell conversation, we developed a new approach of using electrodes to record groups of brain cells that were anatomically connected. We first mapped neural connections in the brain via diffusion tensor imaging, which uses an MRI scanner to measure the movement of water along neural connections. We then used these images to implant electrodes at the endpoints of the neural connections shared by the pulvinar and the visual cortex.

"Our mapping of these communication networks and our finding that the pulvinar is vital to attention prompts a new consideration of the mechanisms behind higher cognitive function. We challenge the common notion that these functions depend exclusively on the cerebral cortex, the outermost layer of the brain responsible for decision-making, attention and language, among other abilities. It also suggests that the prevailing view that visual information is transmitted solely through a network of areas in the visual cortex needs to be revised to include the pulvinar as an important regulator of neural transmission."

The paper "The Pulvinar Regulates Information Transmission Between Cortical Areas Based on Attention Demands" was published Aug. 10 by Science, and was supported by the National Science Foundation and the National Eye Institute, part of the National Institutes of Health.

Information for news media

Saalmann is available to discuss his research with interested members of the news media and can be contacted at saalmann@princeton.edu, 609-258-8318, or through Princeton University science writer Morgan Kelly at 609-258-5729 or mgnkelly@princeton.edu.

Morgan Kelly | EurekAlert!
Further information:
http://www.princeton.edu/main/news/archive/S34/52/20C50/

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>