Using the GUI (2): Parameters and Conditions
Parameters
You need to specify the following parameters:
Screen resolution in your experiment (x and y), in the current example is 1280×1024.
The resolution of the presented stimuli during experiment (in pixel), here is also 1280×1024.
Screen size in centimeters, in this case 37×30 cm.
Participant distance to the screen (83 cm).
The parameters are mandatory to be filled before proceeding.
Please note: the fixation X and Y from your input file should be a relative fixation location in reference with the stimuli. See below as an example.
Predictors
First specify the columns that refer to Subject, Trial, fixation X, Y and Duration.
iMap4 will then ask for the predictors you would like to include in the modeling (your experiment conditions – fixed effects, and random covariance you would like to control – random effects). The selected variables will be saved in PredictorM.mat as one of the output files.
Please note: verify carefully whether you would like to treat your predictors as continuous (e.g., subjective rating) or categorical (e.g., gender). By default, the type of predictor is set to categorical if it has less than 5 levels.
A pop-up window will appear for you to specify the fixation map type (the value on the map represents either fixation durations or fixation numbers). Moreover, you could include or exclude specific fixation (e.g., exclude the first fixation).
Now you can proceed to the next step in the GUI: Smoothing Methods