Stimulus component

The stimulus component construct provides a placeholder for stimulus components. On each trial, this placeholder will contain a stimulus component from the stimulus set assigned to the trials timeline. All the stimulus properties along with start time, end time and (actual) duration are recorded.

Creating a stimulus component

Stimulus components can be added to trials timelines. First ensure that there is a stimulus set assigned to the trials timeline then click New item, select Stimulus component from the type list and select one of the available components presented.

Editing stimulus component

Click anywhere along its row (Figure 1) to open the editor.

Figure 1. Open construct editor (Psychstudio)

Figure 1. Open construct editor

If your stimulus component consists of multiple component groups (i.e. the component group type is either blended or counterbalanced), editing can be performed on the sub-components by selecting them from the stimulus group selection list (Figure 2).

Figure 2. Component selector (Psychstudio)

Figure 2. Component selector

Editing events

Stimulus components can use events to move the study forward in a similar way to keyboard responses and buttons responses. In edit mode, stimulus image and stimulus text components can be assigned an event to be triggered by clicking (or touching for touch devices) the component by selecting an event from the Click event dropdown menu. Stimulus audio and stimulus video components can be assigned an event to be triggered when the media finishes by selecting an event from the Media ended event dropdown menu.

Editing timing

In edit mode, the following properties can be set via the timing table:

Start mode
- Fixed: start time will be measured from the beginning of the trials timeline.
- Offset from previous item: start time will be measured from the end of the previous item on the trials timeline. If there is no previous item, or the timeout of the previous item is set to nil(infinite), then start time will be measured from the beginning of the trial.
Start time (ms): when to initiate construct.
Duration mode
- Fixed: duration will be a fixed time period.
- Random: duration will be a random time period bound by minimum and maximum values.
- Factor: duration will be a randomly chosen level from the factor selected.
- Level: duration will be set to the value of the chosen level.
Timeout (ms): duration of construct presence.