DEVICE: How To: Synchronize E-Prime with an incoming marker/press via an Input Mask [34380]

This article applies to:

E-Prime 3.0

E-Prime 2.0

E-Prime 1.x

Detail

What Device am I Using?
If using Chronos and you have an Input wired to a Digital Input or Analog Input, refer to DEVICE: Chronos as a Response Device [24491] for a listing of what key the Inputs use.

If you are using a device that can be registered as a Human Interface Device (HID) such as the Celeritas system, you can use a Keyboard device to register the Input.

A ParallelPort and Port device can also be added to the Experiment Object Property Pages > Devices tab to be used as an Input Device.

Example Use Case
A common example of needing an Input to synchronize with E-Prime is during a fMRI experiment. If using E-Prime Extensions for fMRI (EEfMRI), this feature is built in along with other additional features such as setting a "zero time". For more information on EEfMRI, see https://pstnet.com/product_category/fmri-research/.

NOTE: Normally in these types of experiments, Cumulative timing is used to keep consistent trial durations.

Adding the Device to the Experiment

In this example, we have a trigger connected from our fMRI scanner to the Celeritas Trigger Input and Chronos Digital Input 1.

NOTE: Celeritas does have its own device but it is a HID device in this example. For more information, see INFO: Differences between Celeritas E-Prime integration and HID [24670].

By default, the Keyboard device is already added to experiments. To utilize the Chronos device in E-Prime, it needs to be added to an E-Prime experiment. To add a Chronos device follow these steps:

1. Open the Experiment Object at the top of E-Studio’s Structure window. 
2. Click on the Devices tab. 
3. Click the “Add…” button at the bottom of the window.
4. Click on the Chronos Device and click the OK button to add the device.

Once a Chronos Device is added to an experiment, the properties of the device may need to be edited on the Responses tab to enable the appropriate pseudo button being used.

NOTE: Chronos is not available in E-Prime 1.x.
 

Receiving the Incoming Signal

In general, you should place the synchronization E-Object after the Instructions and before the test trials begin.

In the example below, a TextDisplay named WaitForScanner is placed prior to TrialList. WaitForScanner has a Duration of Infinite which allows is to stay on the screen until a trigger is detected.

For the Input Mask, the device (e.g., Chronos or Celeritas) needs to be used with the Allowable set to the expected input. For example, 1 can be used for the Allowable with Chronos. The benefit of using 1 for Input is that you can respond with 1 on Chronos to move on if piloting the study.

See Also:

TIMING: Event vs. Cumulative Mode Timing [18285]