A paralyzed patient implanted with a brain-computer interface device has allowed scientists to determine the relationship between brain waves and attention.
Characteristic activity patterns known as beta and delta oscillations have been observed in various regions of the brain since the early 20th century, and have been theoretically associated with attention. The unique opportunity to record directly from a human subject's motor cortex allowed University of Chicago researchers to investigate this relationship more thoroughly than ever before.
"This gave us a really unique opportunity to record, at the micro scale, signals from the human motor cortex," said Hatsopoulos, professor in the Department of Organismal Biology and Anatomy and Chair of the Committee on Computational Neuroscience.
The experiments, published this week in the journal Neuron, reveal the intricate dynamics of the attentive brain. Beta oscillations can be read as a reflection of how much attention a subject is paying to the task at hand, while slower delta oscillations act as an internal metronome, allowing the brain to anticipate moments when attention is most needed.
"Our study shows that when a person can count at a rhythm provided by an external stimulus, your brain can act as a metronome to take advantage of this timing and become more efficient," said Maryam Saleh, graduate student in the Committee on Computational Neuroscience and lead author of the study.
The experimental subject was implanted with a BrainGate neuroprosthetic implant in 2006, a device that allows quadriplegic individuals to control a computer cursor using brain activity. As part of a clinical trial, a small chip containing nearly 100 microelectrodes was implanted in the subject's primary motor cortex, where electrical signals could be translated by computer into cursor motion directed by the patient's thoughts.
In the experiments described in Neuron
|Contact: Rob Mitchum|
University of Chicago Medical Center