This article applies to:
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  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 .
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:
- Open the Experiment Object at the top of E-Studio’s Structure window.
- Click on the Devices tab.
- Click the “Add…” button at the bottom of the window.
- 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.