It was another busy Noggin Wednesday, with young people curious to hear more from our student volunteers, this time about drugs, sleep, and the electrical nature of information flow in the brain..!
Fueled by donated food from Mother’s Bistro, we challenged each other to the Mindflex Duel – adjusting our wirelessly transmitted frontal lobe brain activity to force a ball, suspended in a stream of blown air, across a track.
This game offers a compelling example of how changing our thoughts (what we attend to, whether we focus on the ball, or solve math problems in our heads) also changes how electrical potentials flow in discrete brain networks – changes that can be detected and referenced to decide who wins!
Kirk Wydner from Portland State University offered another direct demonstration of the electrical nature of brain activity, using an EEG kit from the creative neuroscientists at Backyard Brains. EEG (or electroencephalography) measures action potentials – electric signals – and those signals it detects reflect the activity of many cells, mostly those near the brain’s surface, all firing at the same time…
Kirk attached electrodes to the back of a volunteer’s skull, above the occipital lobes (close to O1 and O2, below), and stuck another “reference” electrode over the bone behind his ear…
Image from BMC Neurol (2011)
He then plugged the inputs into a computer, which instantly displayed the dramatic amplified tracings reflecting the busy neural firing of cells in the occipital lobes, at the back of the brain, where activity from the eyes first arrives in cortex…
With your eyes open, and your visual brain areas firing in response to many complex aspects of what you see (colors, shapes, etc), the EEG tracings are pretty fast (“beta” activity), with low wave height, or amplitude – because many different, smaller, specialized brain regions are busy processing many different things…
But with eyes closed, there is suddenly no visual input to occipital cortex, so neurons there reduce their firing rate, slowing the EEG tracings (you get an “alpha” rhythm). Also, more cells now fire together, summating their action potentials – which increases the amplitude of the resulting waves…
Carrie Miyamoto from PNCA, and Gaile Parker from PSU, also offered folks the chance to screen print their own t-shirts, with some creative designs we’d worked on during earlier Noggin Wednesdays…
Many thanks again to P:ear – Wednesday is our favorite day of the week 🙂
