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Recording of mouse position at locations which should not be possible

URL of experiment: Pavlovia (for test run, just type in any info in prescreen, variable “group” needs to be ‘A’,‘B’, ‘C’, or ‘D’

Description of the problem: My experiment requires the recording of the mouse position. One trial starts when participants click on a square, presented in the center of the screen, after which three successive circles are presented and the participants have to indicate the location of the third circle. My inquiry concerns the Mouse data recorded for the initial square.

The initial square is 15 x 15 Pixel and I used the builder component mouse to specify that the square has to be clicked on and that for this click the position has to be recorded - see here:

In my understanding, the recorded X and Y position of the mouse should therefore always range between +7 and -7 (as the square was centered on the center of the screen and the square was 15x15 pixel).
After I have run my experiment, I saw that sometimes, the recorded x and y position was out of this range (especially dataset5 pops up as in this dataset the recorded x and y position has values of +/- 80 or so). I have exported all information stored about the mouse position concerning the square here: Mouse_position_MSqu.csv (510.8 KB)

Since my main interest is about the localization of the circle, it is important for me to understand how psychoPy / PsychJS records the location and indicated positions of the mouse - and right now I don’t understand how this mouse position data for clicking on the square is possible. Any help would be greatly appreciated!