The Builder view of the PsychoPy application is designed to allow the rapid development of a wide range of experiments for experimental psychology and cognitive neuroscience experiments.
The Builder view comprises two main panels for viewing the experiment’s Routines (upper left) and another for viewing the Flow (lower part of the window).
An experiment can have any number of Routines, describing the timing of stimuli, instructions and responses. These are portrayed in a simple track-based view, similar to that of video-editing software, which allows stimuli to come on go off repeatedly and to overlap with each other.
The way in which these Routines are combined and/or repeated is controlled by the Flow panel. All experiments have exactly one Flow. This takes the form of a standard flowchart allowing a sequence of routines to occur one after another, and for loops to be inserted around one or more of the Routines. The loop also controls variables that change between repetitions, such as stimulus attributes.
For a simple reaction time experiment there might be 3 Routines, one that presents instructions and waits for a keypress, one that controls the trial timing, and one that thanks the participant at the end. These could then be combined in the Flow so that the instructions come first, followed by trial, followed by the thanks Routine, and a loop could be inserted so that the Routine repeated 4 times for each of 6 stimulus intensities.
There are a couple of demos included with the package, that you can find in their own special menu. When you load these the first thing to do is make sure the experiment settings specify the same resolution as your monitor, otherwise the screen can appear off-centred and strangely scaled.
This runs a digital demonstration of the Stroop effect [1]. The experiment presents a series of coloured words written in coloured ‘inks’. Subjects have to report the colour of the letters for each word, but find it harder to do so when the letters are spelling out a different (incongruous) colour. Reaction times for the congruent trials (where letter colour matches the written word) are faster than for the incongruent trials.
[1] | Stroop, J.R. (1935). “Studies of interference in serial verbal reactions”. Journal of Experimental Psychology 18: 643-662. |
This is a mini psychophysics experiment, designed to find the contrast detection threshold of a gabor i.e. find the contrast where the observer can just see the stimulus.