To generate random stimuli of different types (auditory, mechanical and/or thermal) using the Richard Gracely Multiple Random Staircase (MRS) method.
Command Communication (Plain Text File) Code.
- The name of the file is : RGMultiStimuli.txt
- The whole file is read in its entirety and all the commands within the file are executed as they are read by the software without waiting for their completion.
- Each line can contain multiple commands, but they must be separated by semicolons (e.g. "T MAX 50 ; T MIN 20").
- Commands are not case sensitive.
Each command must start with the identification of the stimulus type to be generated:
- A - for Auditory
- E - for Electrical
- M - for Mechanical
- T - for Thermal
Followed by at least one space.
Followed by the command code:
- ON - to turn on the associated stimulator.
- OFF - to turn off the associated stimulator.
- MAX - to specify the maximum stimulus amplitude.
- MIN - to specify the minimum stimulus amplitude.
- BAS - to specify the baseline: the stimulus amplitude to which the stimulus will return after its specified duration.
- AMP - to set the amplitude of the stimulus or the name of the sound (wav) file for the Auditory stimulus when not in "Volume Controlled" mode (See: Auditory Stimulus Special Considerations).
- DUR - to set the duration of the stimulus in seconds.
If the duration is not specified, the stimulus stays at the same value until the next command to change it.
If a timed stimulus is on going:
- If the duration is set to zero then the on-going stimulus is terminated and the amplitude is returned to baseline.
- Otherwise the new duration command is lost and the stimulus will return to baseline when the previous command duration times out.
- WAV - to specify the sound (wav) file to be played for the Auditory stimuli when in "Volume Controlled" mode.
Followed by at least one space.
Followed by a quantity or identification, if required:
Auditory Stimulus Special Considerations.
- "ON" and "OFF" commands: no quantity required.
- "MAX", "MIN", "BAS" and "AMP" commands: the quantity is given in the associated units.
- "DUR": the quantity must be in seconds
The auditory stimuli can be delivered in two different modes:
Auditory Mode Selection.
- Volume Controlled Mode. The same relatively large wav file is played for all the stimuli and:
- The Amplitude is controlled by software direct speakers/head phones volume control.
- The Duration is controlled by interrupting the playing of the file by playing a short "No Sound" wav file. This file (NoSound.wav) must be present in the application folder.
- Custom Generated Wav files.
The Auditory stimuli are delivered through pre-generated sound (wav) files (link to UNC sound generating software page). Their amplitude and duration are not changed by this VB interface and will be played "as is" no matter the duration command setting.
However, a scheme was developed to display the "actual" amplitude and duration of the sound:
- The beginning of the sound file name is used as amplitude. For instance, the file name: "50-00-400-250-3000.wav" will result in a displayed amplitude equal to 50.00 % of full volume.
- The end of the sound file name can be used as duration. For instance, the file name: "50-00-400-250-3000.wav" will result in a displayed duration equal to 3.000 sec.
The idea is to follow this scheme to name the sound files:
Auditory Modulation feature. New August 2010
- Volume Controlled Mode can be entered by sending "A Wav <filename>" where <filename> is the name of the sound file to be used by all stimuli.
e.g. "A wav 3001.wav ; A dur 1 ; A amp 25 " will set the "Volume Control" mode using "3001.wav" for basic sound at a volume 25% of the hardware volume current setting. For a duration of 1 second.
- Custom Wav File Mode is the default mode that can be re-entered by sending "A Wav " as command without a file name.
e.g. "A wav ; A amp 2226-2239-3001-3113.wav" will set the "Custom Wav File" mode playing the file: "2226-2239-3001-3113.wav" as is (amplitude and duration included).
Rather than having a continuous sound, it is sometime desirable to have the sound interrupted at regular intervals. This can be achieved by setting the "Sound On" and "Sound Off" text boxes to the required setting.
These text boxes are located in a small panel visible under the main "Auditory" panel when the stimulator is ready (The "Ready" green indicator is on).
If any of these values is set to zero or less, there is no modulation.
The "Duration" is then equal to the sum of the On times.
Basic initialization of all the categories-
Sets the maximum, minimum, baseline and the current amplitude commands.
turns on the auditory, mechanical and thermal interfaces; turns off the electrical interface:
A MAX 101 ; M MAX 45 ; T MAX 50
A MIN 0 ; M MIN 0 ; T MIN 20
A BAS 0 ; M BAS 0 ; T BAS 32
A AMP 0 ; M AMP 0 ; T AMP 32
A on ; M on; T on
Sets the mechanical stimulus amplitude to 32.5 for a duration of 5 seconds,
Sets the thermal stimulus amplitude to 42 for a duration of 6 seconds,
Sets the auditory stimulus to play the "wav" file: "50-00-400-250-3000.wav"
The first two numbers will be displayed as the amplitude, and the last number will be used as a duration in milliseconds, whether or not they represent the actual amplitude and duration of the sound wave.
m amp 32.5 ; m dur 5
t amp 42 ; t dur 6
a amp 50-00-400-250-3000
Multiple Stimuli Interface application program: Old version of "MultiStimuli.exe".
Quad Stimuli Interface application program (November 2011): Old version of "QuadStimuli.exe".
Quad Stimuli Interface application program for MRI TTL pulse counting: "QuadStimuli_MRI.exe".
Quad Stimuli Interface application program for fibromyalgia and other studies: "QuadStimuli_Psychophys.exe".
version of the QuadStimuli software for WINDOWS 7
, that as of the 22nd of March 2012 still needs to be tested, can be downloaded at: "QuadStimuli_W7.exe".
A NEW DLL
for the Win7 version of the QuadStimuli can be placed in the same folder as the application: "LJDotNet.dll".
Text File samples (Extensions to be changed to ".txt" to affect the MultiStimuli program when running):
Sound Generator application program:
Sound File Samples:
All the files, except for the sound generator, must be in the same folder.
The "Auditory" stimuli are delivered by means of the available computer sound system.
- First, sound "wav" files must be generated ahead of time by means of a "Sound Generator" application program such as:
the UNC pakage that can be downloaded from the "Sound Experiment Help" web page.
- For convenience, the sound wave files should be named as indicated above, under the title : "Auditory Stimulus Special Considerations"
- The computer sound volume should be set (probably to its maximum) and left in the same position for the duration of the experiment.
- The sound files used during the test should be played at the same volume level, on the same computer, and analyzed by means of a sound level meter,
for calibration purpose.
TSA II Hardware particularities.
The TSA II Hardware driver is a Visual Basic 2008 (VB.NET) program based on a Medoc Visual Basic(vb6) package. This package requires a few files to be present in the same folder in order to run.
A list of these files can be found at the "Medoc TSA II & Pathway Thermal Stimulators"
The TSA II power should be on at least 20 seconds before a "Thermal" stimulator "On" command is sent to the "Multiple Stimuli Software", which causes "SHOVAL.EXE" to initialize the hardware.
This initialization normally takes approximately 10 seconds if every thing goes well, and sometime closer to 30 seconds.
Recommended steps to perform the first time the TSA is used:
Remarks about every day use of the TSA:
- Ascertain that all the Medoc files required to run the TSA are present in the main "Multiple Stimuli" package folder:
"SHOVAL32.EXE", "AAA.DRV", "Options.ini", "VATOD.DRV", "VSAATOD0.DRV", "VSAATOD1.DRV", "VSATABLE.DRV", "BLACKBOX.DAT" and "LogVAS.drv".
- Test run a Medoc package such as "WINTSA.EXE" or "Covas.exe" to make sure the TSA II is running properly.
Open the "Utility" ==> "Setup" (See picture) and check:
- That the Thermode type/size (16x16 or 30x30) is correct.
- The RS232 communication port (COM) number associated with the thermode.
- Open the TSAII initialization file "Options.ini" and check the entries for the thermode type and the COM port:
Edit the file if incorrect (make sure not to add any spaces).
If the thermode has a size of 16x16, the line should read: "Thermode=1"
If the thermode has a size of 30x30, the line should read: "Thermode=0"
Edit the "port=COM5" if the thermode is connected to a different port.
You can also change the maximum temperature to a different value if you desire.
Shortly after sending a "Thermal" "On" command to the "Multiple Stimuli" software, the Medoc "TSA initialization"
It is best to patiently wait for its completion.
When all is well, the TSA II starts its water pump with its distinctive chatter, and the initialization window automatically hides behind the main window.
When things do not go so well the software may send an alarming series of error messages which means things just did not go as expected, and a review of the steps mentioned above for the first time the TSAII is used may be necessary.
TSA II Calibration.
Sorry, but the Medoc company does not provide a hardware calibration for its TSAII.
Thermal Gradient & Subject Response Time.
- To measure the Medoc TSAII temperature gradient.
- To measure the subject response time.
When the "Subject response ON" check box is checked, the small panel below it appears.
- Both measurements (the temperature gradient or "Ramp" and the "Subject response") start when the thermode temperature reaches the "From" temperature that must be entered by the user and must have a value between the starting temperature (the baseline) and the final temperature (the stimulus amplitude).
- The "Ramp" measurement stops when the "To" temperature is reached. The user must also enter the "To" temperature that must have a value between the "From" temperature and the final temperature.
- The "Subject response" measurement stops when the subject presses one of the TSAII "Subject Response Device" buttons (modified computer mouse)
- Pressing a "Subject Response Device" button also aborts the stimulus: the thermode temperature returns to baseline.
- Notice that if the subject responds before the "To" temperature has been reached no temperature gradient measurement can be performed.
- The "Direct_Quad_Stimuli" Tcl program originally designed to debug this Multi Stimuli system is a simple way to control the execution of these measurements.
- The "Ramp" in °C/sec
- Its duration in milliseconds
- And the subject response time in milliseconds, from the beginning of the ramp ("From" time).
2008 September 24
Last updated 2012 March 24