Template: Visual World Paradigm ("Click on...")
Visual World Paradigm ("Click On ...")

Required Experiment Builder Version: 1.4.55 or higher
EyeLink Required: Yes
Type: Complete Example
Difficulty Level: Moderate

This example illustrates:
  • How to implement transparency manipulation
  • How to use ASIO driver to play synchronized audio playing
  • How to use Mouse trigger to click on an item
  • How to use a Custom Class to process Interest Area information

This experiment is a variant of the Visual World paradigm. The participant will see a display containing four items and hear an audio instruction "click on the grapes". Use the computer mouse to select the target. Feedback graphics will be displayed to indicate whether the response is correct (green) or incorrect (red).

Attached are two ways to implement this task. The "VisualWold_Click.ebz" example uses the standard nodes available in Experiment Builder. The "VisualWold_Click_CC.ebz" example implements the same task using Custom Class code to process Interest Area information. 

You can view the Custom Class source code in the "VisualWold_Click_CC.ebz" example by clicking on the "CUSTOM_CLASS_INSTANCE" node in the RECORDING sequence. You may also check out the "Custom Class" section of the Experiment Builder User Manual on how to use Custom Class in Experiment Builder. The "RESETS_IAS" node before the PREPARE_SEQUENCE node is used to reset the trial parameters (current selection) and to pass along the positions of the small images used in the current trial. The mouse click is handled by the MOUSE_CLICK trigger in the recording Sequence - please note that its location is set to (0, 0) and region width and height are set to 1024 and 768. The mouse trigger passes the current click position to the FIND_ITEM_CLICKED execute action. The FIND_ITEM_CLICKED calls the custom class method findCurrentIA(self, x, y, width, height) to determine which of the images has been clicked. If a valid image is clicked, the experiment flows go further to draw feedback graphics on top of the images; otherwise, it looks back to the NULL_ACTION.

NOTE: Please see our Implementing Visual World Paradigm in Experiment Builder Webinar for more considerations of the Visual World Paradigm.

  1. Download the VisualWorld_Click_CC.ebz or VisualWorld_Click.ebz example.
  2. Launch the Experiment Builder application.
  3. Unpack the VisualWorld_Click_CC.ebz or VisualWorld_Click.ebz file to a location on your Experiment Builder PC with "File menu -> Unpack".
  4. Open the project in Experiment Builder.
  5. Deploy the project to a new folder.
  6. Run the VisualWorld_Click_CC.exe or VisualWorld_Click.exe from the deployed directory.

.ebz   VisualWorld_Click.ebz (Size: 130.33 KB / Downloads: 216)

.ebz   VisualWorld_Click_CC.ebz (Size: 134.75 KB / Downloads: 78)