David Wallace Croft
2006 Feb 22 Wed
Newt Cyborg is a software simulation of a limb controlled by nerve
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
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",
"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
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.
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 (http://www.apache.org/).
In particular, it uses the
Jakarta Commons Math library for statistics.