CroftSoft / Library / Software

Newt Cyborg

David Wallace Croft

2006 Feb 22 Wed


Newt Cyborg is a software simulation of a limb controlled by nerve activity.

In this simulation, input from the joystick is translated into nerve activity represented by spikes. The spikes are then used to control a cursor on the screen representing a fingertip moving in two dimensions. Four nerves are required to represent signals for extension, flexion, abduction, and adduction of the limb by muscle contractions.


The application is downloaded, installed, and launched by clicking on the screenshot image at the top of this webpage or this link. If the download fails, the user should verify that a recent version of Java has been installed on the computer.


The application originally used a Saitek Cyborg joystick for input. This was replaced by a mouse-controlled virtual joystick to make the program more universal. The user should attempt to move the cursor to the target using the virtual joystick in as little time as possible and hold it on target for three seconds.

In "Automatic" mode, the computer will demonstrate the task. Switch to "Manual" mode to use the mouse to perform the task yourself.

The joystick input ranges from -1 to +1. The default setting for the control input transformation is "Linear". Other options include "Cumulative" for the cumulative distribution function, "Exponential", "Logarithmic", and "Sigmoidal". The input to and output from the functions are scaled or clipped so that the spiking rate falls between zero and the maximum.

The slider adjusts the gain of the transform functions. Setting "Max" adjusts the maximum spiking rate for the axons.

The log displays descriptive statistics for the time in seconds that it takes to complete the task: most recent time (X), sample size (N), mean (M), and standard deviation (S). The "Reset" button resets the statistics. The "Clear" button clears the log.

The "Real-time" checkbox toggles a real-time delay for the simulation loop. Unchecking the "Real-time" checkbox permits the simulation loop to run faster than real-time.

The "Animate" checkbox toggles animation. When animation is off, descriptive statistics will be recorded to the log only once every ten seconds. Unchecking both the "Real-time" checkbox and the "Animate" checkbox permits the simulation loop to run as fast as possible.


Documentation is available in format.


This software is being developed under the guidance of Dr. Lawrence J. Cauller of the School of Behavioral and Brain Sciences (BBS) at the University of Texas at Dallas (UTD) as part of a first year doctoral research project for the programmer, David Wallace Croft.

Open Source

The source code is available for reuse under the terms of the Academic Free License.

This product includes software developed by The Apache Software Foundation ( In particular, it uses the Jakarta Commons Math library for statistics.

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