Differentiate between Left & Right Shift/Alt keys [29987]

This article applies to:
E-Prime 3.0
E-Prime 2.0
E-Prime 1.x

 
Detail
This sample demonstrates using the .DATA property of the ResponseData object to differentiate between left and right SHIFT/ALT key presses.
 
Abstract
The .RESP property of a ResponseData object will return bracket notation of the participant's response if a special character key was pressed. For example, pressing the left SHIFT key will result in a .RESP value of '{SHIFT}'. However, the ResponseData object also has a .DATA property that returns the device specific entry for the response. That is, a unique integer value of the key that was pressed. For example, the left SHIFT key will return a .DATA value of '42', and the right SHIFT key will return a .DATA value of '54'.

 
Since the left or right SHIFT/ALT keys cannot be specified within the E-Studio GUI, InLine script following the 'Stimulus' object must use the .DATA property to determine which key was pressed. In the first block of trials, this is used to simply set the appropriate Stimulus.ACC value. In the second block of trials, a GoTo command is also used to loop back to the 'Stimulus' object until the subject presses the correct key.