William L. Ditto

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In a spontaneously bursting neuronal network in vitro, chaos can be demonstrated by the presence of unstable fixed-point behaviour. Chaos control techniques can increase the periodicity of such neuronal population bursting behaviour. Periodic pacing is also effective in entraining such systems, although in a qualitatively different fashion. Using a strategy(More)
The extreme sensitivity to initial conditions that chaotic systems display makes them unstable and unpredictable. Yet that same sensitivity also makes them highly susceptible to control, provided that the developing chaos can be analyzed in real time and that analysis is then used to make small control interventions. This strategy has been used here to(More)
1. The effects of relatively small external DC electric fields on synchronous activity in CA1 and CA3 from transverse and longitudinal type hippocampal slices were studied. 2. To record neuronal activity during significant field changes, differential DC amplification was employed with a reference electrode aligned along an isopotential with the recording(More)
The main contribution of this work is the development of a high-dimensional chaos control method that is effective, robust against noise, and easy to implement in experiment. Assuming no knowledge of the model equations, the method achieves control by stabilizing a desired unstable periodic orbit with any number of unstable directions, using small(More)
Sudden cardiac death is the leading cause of death in the industrialized world, with the majority of such tragedies being due to ventricular fibrillation. Ventricular fibrillation is a frenzied and irregular disturbance of the heart rhythm that quickly renders the heart incapable of sustaining life. Rotors, electrophysiological structures that emit rotating(More)
Bruce J. Gluckman,1,2 Theoden I. Netoff,2,3 Emily J. Neel,2 William L. Ditto,4 Mark L. Spano,1 and Steven J. Schiff2,3 1Naval Surface Warfare Center, Silver Spring, Maryland 20903 2Department of Neurosurgery, Children’s National Medical Center and The George Washington University School of Medicine, Washington, D.C. 20010 3Program in Neuroscience, The(More)
We describe and discuss in detail some recent results by Sinha and Ditto [Phys. Rev. Lett. 81, 2156 (1998)] demonstrating the capacity of a lattice of threshold coupled chaotic maps to perform computations. Such systems are shown to emulate logic gates, encode numbers, and perform specific arithmetic operations, such as addition and multiplication, as well(More)
Chaotic systems can yield a wide variety of patterns. Here we use this feature to generate all possible fundamental logic gate functions. This forms the basis of the design of a dynamical computing device, a chaogate, that can be rapidly morphed to become any desired logic gate. Here we review the basic concepts underlying this and present an extension of(More)
We provide experimental evidence for the emerging imbalance in the firing activity of two distinct classes (type 1 and type 2) of population spikes recorded from the hippocampal area CA1 in an animal model of temporal lobe epilepsy. We show that during the latent period of epileptogenesis following status epilepticus inducing brain injury, there is a(More)