It was the world’s first electroencephalogram (EEG) recording — but nobody took much notice.
It was the world’s first electroencephalogram (EEG) recording — but nobody took much notice.Tags: Sony Corporation Future Tense Case StudyResearch Design For DissertationRomans HomeworkScholarship Essay TopicsBboy Thesis Vs WingInternational Terrorism Research Paper
Randolph Helfrich at the University of California, Berkeley, and his colleagues devised a way to enhance or reduce gamma oscillations of around 40 hertz using a non-invasive technique called transcranial alternating current stimulation (t ACS).
By tweaking these oscillations, they were able to influence whether a person perceived a video of moving dots as travelling vertically or horizontally.
“The result was so mind-boggling and so robust, it took a while for the idea to sink in, but we knew we needed to work out a way of trying out the same thing in humans,” Tsai says.
Scientists identified the waves of electrical activity that constantly ripple through the brain almost 100 years ago, but they have struggled to assign these oscillations a definitive role in behaviour or brain function.
It was only after his colleagues began to confirm the results several years later that Berger’s invention was recognized as a window into brain activity.
Neurons communicate using electrical impulses created by the flow of ions into and out of each cell.“For the longest time, I didn’t believe it,” she says.Her team had managed to clear amyloid from part of the brain with a flickering light.Tsai’s study was the first glimpse of a cellular response to brainwave manipulation.“Her results were a really big surprise,” says Walter Koroshetz, director of the US National Institute of Neurological Disorders and Stroke in Bethesda, Maryland.These tend to occur in deep sleep (see ‘Rhythms of the mind’).At any point in time, one type of brainwave tends to dominate, although other bands are always present to some extent.For an hour each day, she placed them in a box lit only by a flickering strobe.The mice — which had been engineered to produce plaques of the peptide amyloid-β in the brain, a hallmark of Alzheimer’s disease — crawled about curiously.The strobe was tuned to 40 hertz and was designed to manipulate the rodents’ brainwaves, triggering a host of biological effects that eliminated the plaque-forming proteins.Although promising findings in mouse models of Alzheimer’s disease have been notoriously difficult to replicate in humans, the experiment offered some tantalizing possibilities.