The task design is an adapted version of the design used in Stout et al., 2015. 

In this task, participant's task is to decide whether a valenced face stimulus changed between screens or not. 
On each trial, participant first attends to the left/right hemifield of the screen based on the arrow prompt.
Next, 4 stimuli appear on each quadrant of the screen. Participant's task is to find the face stimulus on the attended side
of the screen.
The distractors (unattended stimuli) are either alcoholic or non-alcoholic beverage images.
There are 120 trials in each emotion (neutral/joy/fear) condition, making a total of 360 test trials.
There are 24 practice trials. Total task duration varies as a function of response time (around 33 minutes). 

Face Stimuli were selected from NimStim database and includes 6 female, 6 male faces with Neutral/joy/fear emotions.
The face stimuli have been turned to black and white, cropped and the white backgrounds in these images have been turned to grey.

The distractor images have been retrieved from chosen from the International Affective Picture System (IAPS).
All pictures have been turned to black and white and matched the face stimuli in terms of entropy (image complexity of grey scale images).

In order to play the game, Download the FaceMatchingGame folder. Navigate to the game folder in Matlab. Drag and drop the DetermineCondition.m on the
command window. Psychtoolbox required.