# Henry Greenside

## Professor of Physics

### Overview

After working in nonlinear dynamics and nonequilibrium pattern formation for many years, my research group has begun studying problems in theoretical neurobiology in collaboration with Professor Richard Mooney's experimental group on birdsong at Duke University. The main scientific question we are interested in is how songbirds learn to sing their song, which is a leading experimental paradigm for the broader neurobiology question of how animals learn behaviors that involve sequences of time. My group is interested in problems arising at the cellular and network levels (as opposed to behavioral levels). One example is understanding the origin, mechanism, and eventually the purpose of highly sparse high-frequency bursts of spikes that are observed in the nucleus HVC of songbird brains (this is the first place where auditory information seems to be combined with motor information). A second example is to understand how auditory and motor information are combined, e.g., there are data that suggests that the same group of neurons that instruct the respiratory and syringeal muscles to produce song (again in nucleus HVC) are also involved in recognizing song. A third example is trying to understand changes in anatomy (increases in spine stability) that were recently observed in living brain tissue as a bird learns its song.

Epureanu, BI, and Greenside, HS. "Fractal basins of attraction associated with a damped Newton's method." *SIAM Review* 40.1 (1998): 102-109.

Krystal, AD, Greenside, HS, Gottschalk, A, Bauer, MS, and Whybrow, PC. "Low-dimensional chaos in bipolar disorder [1] (multiple letters)." *Archives of Internal Medicine* 158.5 (1998): 275--.

Zoldi, SM, and Greenside, HS. "Spatially localized unstable periodic orbits of a high-dimensional chaotic system." *Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics* 57.3 SUPPL. A (1998): R2511-R2514.

Krystal, AD, Greenside, HS, Gottschalk, A, and Bauer, MS. "Low-dimensional chaos in bipolar disorder? [1] (multiple letters)." *Archives of General Psychiatry* 55.3 (1998): 275--.
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Strain, MC, and Greenside, HS. "Size-dependent transition to high-dimensional chaotic dynamics in a two-dimensional excitable medium." *Physical Review Letters* 80.11 (1998): 2306-2309.

Krystal, AD, Zaidman, C, Greenside, HS, Weiner, RD, and Coffey, CE. "The largest Lyapunov exponent of the EEG during ECT seizures as a measure of ECT seizure adequacy." *Electroencephalogr Clin Neurophysiol* 103.6 (December 1997): 599-606.

Krystal, AD, Coffey, CE, Weiner, RD, Rapp, PE, Albano, A, Greenside, HS, DeMasi, M, and Cellucci, C. "EEG correlates of the response to ECT." *BIOLOGICAL PSYCHIATRY* 41 (April 1, 1997): 189-189.

Zoldi, SM, Krystal, AD, and Greenside, HS. "Statistical analysis of redundancy and stationarity in multi-channel EEG." *JOURNAL OF MATHEMATICAL PSYCHOLOGY* 40.4 (December 1996): 354-355.

Krystal, AD, Greenside, HS, Weiner, RD, and Gassert, D. "A comparison of EEG signal dynamics in waking, after anesthesia induction and during electroconvulsive therapy seizures." *Electroencephalogr Clin Neurophysiol* 99.2 (August 1996): 129-140.

O'Hern, CS, Egolf, DA, and Greenside, HS. "Lyapunov spectral analysis of a nonequilibrium Ising-like transition." *Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics* 53.4 SUPPL. A (1996): 3374-3386.