For the 2010 VB.NET software version

See "Magnitude Estimation Software 2010"
This software version was made for a modified "Thumb Nail" controller based on the LabJack U12 DAQ specially modified for the PsychoPhysiology experiment.

For the 2011 VB.NET software version for LabJack U3 hardware

See "Magnitude Estimation 2011"


Original Version
The original specifications for the UNC "Magnitude Estimation" device defined a handle with a 16" linear travel with which a subject could input a value of 0 to 100% estimated pain into the data acquisition computer.
The device used an optical position encoder. Its advantages were stability and immunization from noise. Its disadvantage was its complexity, requiring a decoding interface card.
The Subject Display was actually the monitor of a second computer that communicated with the main computer through a serial ( RS232) port.

Current Version
The current system is design to work on a dual display computer.  The mechanical magnitude estimation device can either consists of a ten turn potentiometer and one or two switches, or consist of a three switch box. One switch increases the magnitude a second one decreases the magnitude, and the third switch can be used as an "Enter" key when an experiment is in progress, or a "Reset" button when the system is idle.

The software has two main components: One displays the output value of the device and instructions to the subject on one monitor, the other allows the user/ investigator to change the information/instructions displayed on the subject's monitor.

Construction / Hardware

Original (Digital) Version (jpeg File1)

Second (Analog) Version (jpeg File2) & (jpeg File3)

Third (Analog) version (jpeg File4) & (jpeg File5)


Original Digital Version (BMP File)

Analog Versions (jpeg File)


Subject Display (Factory Defaults jpeg File)
The subject display fonts, colors, styles and sizes can be edited through the user interface "Fonts & Styles". (Example jpeg file)

User Interface
This Interface can be used as a stand alone interface, but is meant to be embedded into a larger package.

Descriptors. The descriptors can be edited and theirs positions adjusted to any position on the Subject Display scale. Setting the position to a value less than zero, will cause the descriptor to disappear.  The changes take effect when the associated "Apply" button or the "Apply All" button is activated.  The new settings can be saved to a file through the "File" menu. They are also saved to a defaults file that will automatically restore them the next time the program is run.

The "Message" with light green background is actually a 7th descriptor without location.  If the "Visible" check box  is not checked, the Message disappears when the "Apply" button is clicked. When the "Visible" check box is checked, then the "Beep" check box permits enabling the sounding of the standard beep when the "Apply button is clicked.
Fonts & Styles (new October 2006)
The user can modify the appearence of the Subject Display by changing the "message" and "descriptors" fonts, colors and styles (not framed, framed flat or framed 3D). The scale font can also be changed, as well as the "descriptors" alignment with their associated vertical lines.
Window and Slider (new October 2006)
"Auto size" causes the subject display to occupy the whole monitor screen.
"Center Display" places the slider near the center of the current window as defined by the settings of its left, width, top and height.
"Undo" restores the latest re-sizing changes.

Tools/Calibration. The Tools menu gives access to a self explanatory calibration procedure (instructions appear on the "Subject Display"). The Magnitude Estimation device maximum display can be set to 100% or 110% as desired.

Sample Defaults File (Text File)

2005 November 15
Last update 2011 June 23