M-VAST (Michigan Visual Aversion Stress Test)

Version 1.0.1

This test is created using PsychoPy 1.85.2 and Python 2.7.11. It maintains compatability with most older versions of PsychoPy and Python.

Overview

M-VAST is a platform where you can design an experiment of a single or multiple stimuli to a viewer paired with an optional rating screen. Some of the provided images have been known to cause heighted discomfort to fibromyalgia patients.

Experiment: A sequence of stimuli presented to a test subject.

Stimuli: An aversive stimulus presented to a test subject paired with an optional rating screen.

Each stimuli has multiple parts. Many except for the actual stimulus itself are optional.

1. Resting Time before Visual Cue *This resting time is a black screen presented to the viewer before the visual cue.
2. Visual Cue *The visual cue is a green cross immediately preceeing the stimulus
3. Visual Stimulus *An aversive visual stimulus
4. Resting Time before Rating Screen *This resting time is a black screen presented to the viewer before the rating screen.
5. Rating Screen *On-screen rating scales are presented to the viewer to rate the aversiveness of the stimulus.

Setup

Executing main.py will open a first screen called Stimulus Setup.

The following fields are present: -Patient ID -Experimenter ID -Age -Sex -Ouput File -Input File -Save or Start Experiment -Stimulus Number

There are four different ways to use the M-VAST setup screen.

Method 1: Start from file

This is the most common way M-VAST is designed to be used. You can create a .csv file with all the stimuli parameters for a specific set of patients and run the exact same experiment on everyone. The input file will be described later.

Method 2: Edit

This method allows you to edit in the current experiment. Select "Edit" and select the Stimulus Number you wish to edit then press "OK". You can continue this process until you have edited all the stimuli you want in your experiment.

Method 3: Start

This method starts the experiment you edited. It's similar to "Start from file" but it uses the edited stimuli rather than the input file.

Method 4: Save to File

This method saves the experiment you edited into a .csv file specified in .

Stimulus Edit

There are 11 parameters to edit

1. Time before Visual Cue(s)

   • Resting time before visual cue

2. Visual Cue Duration (s)

   • Duration of stimulus

3. Stimulus Type

   • 3 types of stimuli with 3 different color combinations
     • 9 total combinations
   • Stimuli Types
     • Annular Checkerboard
     • Checkerboars
     • Strobe Light
   • Color Combinations
     • Black/White
     • Blue/Yellow
     • Red/Green

4. Stimulus Duration(s)

   • Duration of the stimulus

5. Stimulus Frequency

   • You can only choose frequncies that have a period of a factor of 1/60
   • The period of the stimuli must be a factor of 1/60th
   • The allowable frequencies are (in Hz):
     • 15
     • 10
     • 7.5
     • 6
     • 5
     • 3
     • 2
     • 1

6. Brightness

   • A linear black filter on the entire stimuli screen is applied
     • 1: no filter
     • 0 : full black filter

7. Time until Rating(s)

   • Time between stimuli and rating screen

8. Response/Rating Type There are 6 response types

   • Brightness (0->100)
   • Unpleasantness (0->100)
   • Dual Scale (0->100) containing both Brightness and Unpleasantness
   • Affective (0->20)
   • Sensory (0->20)
   • Dual Scale (0->20) containing both Affective and Sensory
     • The (0->100) scales are horizontal
     • (0->20) scales are vertical.

9. Response/Rating Time(s)

   • Time allowed to rate the stimulus.

10. Limit Response Time/Countdown?

    • 1 - Yes: Limit response time.
    • 0 - No: No Limit on response time.

Example CSV File

sample_test.csv

Time before Visual Cue	Visual Cue Duration	Stimulus Type	Stimulus Duration	Stimulus Freqeuncy	Brightness	Time until rating	Rating Type	Rating Time	Countdown?
1	1	1	1	10	1	3	1	10	1
1	1	1	2	10	1	2	3	10	1
1	1	1	1	10	0.5	1	2	10	0
1	1	1	2	10	0.5	0	4	10	0