Research has shown that when we pay attention, some of these neurons begin firing in unison, like a chorus rising above the noise. Now, a study in the May 29 issue of Science reveals the likely brain center that serves as the conductor of this neural chorus.
MIT neuroscientists found that neurons in the prefrontal cortex — the brain’s planning center — fire in unison and send signals to the visual cortex to do the same, generating high-frequency waves that oscillate between these distant brain regions like a vibrating spring. These waves, also known as gamma oscillations, have long been associated with cognitive states like attention, learning, and consciousness.
“We are especially interested in gamma oscillations in the prefrontal cortex because it provides top-down influences over other parts of the brain,” explains senior author Robert Desimone, director of the McGovern Institute for Brain Research and the Doris and Don Berkey Professor of Neuroscience at MIT. “We know that the prefrontal cortex is affected in people with schizophrenia, ADHD and many other brain disorders, and that gamma oscillations are also altered in these conditions. Our results suggest that altered neural synchrony in the prefrontal cortex could disrupt communication between this region and other areas of the brain, leading to altered perceptions, thoughts, and emotions.”
To explain neural synchrony, Desimone uses the analogy of a crowded party with people talking in different rooms. If individuals raise their voices at random, the noise just becomes louder. But if a group of individuals in one room chant together in unison, the next room is more likely to hear the message. And if people in the next room chant in response, the two rooms can communicate.
In the Science study, Desimone looked for patterns of neural synchrony in two ”rooms” of the brain associated with attention — the frontal eye field (FEF) within the prefrontal cortex and the V4 region of the visual cortex. Lead authors Georgia Gregoriou, a postdoctoral associate in the Desimone lab, and Stephen Gotts of the National Institute of Mental Health, trained two macaque monkeys to watch a monitor displaying multiple objects, and to concentrate on one of the objects when cued. They monitored neural activity from the FEF and the V4 regions of the brain when the monkeys were either paying attention to the object or ignoring it.
When the monkeys first paid attention to the appropriate object, neurons in both areas showed strong increases in activity. Then, as if connected by a spring, the oscillations in each area began to synchronize with one another. Desimone’s team analyzed the timing of the neural activity and found that the prefrontal cortex became engaged by attention first, followed by the visual cortex — as if the prefrontal cortex commanded the visual region to snap to attention. The delay between neural activity in these areas during each wave cycle reflected the speed at which signals travel from one region to the other — indicating that the two brain regions were talking to one another.
Desimone suspects this pattern of oscillation is not just specific to attention, but could also represent a more general mechanism for communication between different parts of the brain. These findings support speculation that gamma synchrony enables far-flung regions of the brain to rapidly communicate with each other — which has important implications for understanding and treating disorders ranging from schizophrenia to impaired vision and attention. “This helps us think about how to approach studying and treating these disorders by finding ways to restore gamma rhythms in the affected brain regions.”
Huihui Zhou, a research scientist in the Desimone lab, contributed to this study. The NIH/National Eye Institute and National Institute of Mental Health supported this research.
Elizabeth A. Thomson | Newswise Science News
New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego
Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
16.01.2018 | Materials Sciences
16.01.2018 | Materials Sciences
16.01.2018 | Power and Electrical Engineering