This task aims to investigate how people discriminate between happy and angry facial expressions. It is possible to select between Method of Constant Stimuli, N-down, and bayesian adaptive Psi-method staircase procedures.
Who is eligible?
Adults with normal or corrected-to-normal vision What does the task consist of? On each trial, a face will briefly appear on the screen. Then, you'll be asked to decide whether the face was ANGRY or HAPPY, using the left and right arrow keys on the keyboard to respond (1AFC). You will have 2 seconds to do this.
The run consists of 60 trials, and will take about 5 minutes.
Want to participate?
Pick a 3-digit subject ID code, e.g. 003
Make sure you have a working installation of Matlab and Psychtoolbox (Windows: You'll also need GStreamer [download here: https://gstreamer.freedesktop.org/data/pkg/windows/1.16.2/gstreamer-1.0-msvc-x86_64-1.16.2.msi]). You can get Psychtoolbox here: http://psychtoolbox.org/download.html
Clone/download 'FADtask_2_Psi' to a directory on your computer. The directory should contain the following: ./code ./data ./stimuli experimentLauncher.m
Use a ruler to measure the height and width of your screen (in cm), and note the distance at which you are sitting from the display (default: 2nd screen if there is one). If you don't have a ruler, you can use the default values later, which are for a 13" screen
To begin the experiment, navigate to the 'FADtask_2_Psi' directory, and run 'experimentLauncher.m', by opening it in Matlab and clicking the green 'Run' arrow button in the Editor toolstrip. You will be asked to enter basic demographic information, your subject ID, and display dimension and viewing distance. If you leave the screen dimensions and viewing distance blank, the default size will be used. Then, the run will begin. Press Esc to quit (partial results will be saved).
When you have completed a run, the data will be saved in ./data/ with your subject ID in a .mat file. Please send this file back.
We appreciate any feedback and bug reports! :) Contact: niianikolova@gmail.com