An item in ScienceDaily (here) reports on research by R Desimone’s group at MIT into gamma waves associated with attention. The report uses an interesting analogy to describe the waves.
Just as our world buzzes with distractions from phone calls to e-mails to tweets the neurons in our brain are bombarded with messages. 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. … 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. …
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. …
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. …
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.
Very interesting article. I might be wrong, but isn’t it reasonable that when the brain is focused on something the different areas of the brain will be coordinated, communicating with each other in order to accomplish their common objective.
When the brain is scattered the different areas are pursuing different tasks/objectives, and they are not communicating properly with each other, because they are in a kind of fight for gaining the other parts collaboration for their cause, which causes their cross messages to lack coordination given that everybody is sending requests and no acknowledge or reply to that requests are sent.
JanetK: Thanks Mariana. I think your right. But the article seems to be making the point that the prefrontal cortex is the area that is initiating the synchrony and therefore presumably initiating the communication. This would imply a top-down rather than a bottom-up control of the focus of attention.
I tend to treat each piece of data as a vague, tentative indication of something and it is only when a number of studies with different methods and perspectives point to the same ‘something’ that I start to think it is probably so. Yes, gamma waves are probably either the sign of consciousness or attention or both. But where they start and what they communicate is another matter not very clear at all.
You are completely right that is an important point, cause is fundamental how the process is done, like you say what part initiates it and what coordinates.