Responding prior to all stimuli

[I][edited by moderator][/I]

I am trying to set-up a modified stroop task. Each trial should run as such: fixation cross (500ms), color face (20ms-540ms), color mask.

The problem I have run into is that subjects are able (correctly) to respond while the face is being presented but before the mask. Currently, the subjects have to wait until the mask is presented in order to respond. Is there any way to allow for responses prior to all stimuli having been presented?

You can place an RT request at any point in the sequence, you do not need to wait until after the last stimulus. The tricky part is dealing with it if you want the stimulus on screen for a fixed time--i.e., not until a response occurs in cases where the response is late. To do this, you can use a min-max value for the trial (see Help). e.g., a min-max value of 0-500! will cause DirectRT to continue to your mask after 500ms if a response has not occurred by that point. If you want variable max values you just need to create multiple styles and apply them accordingly.

Important note: One restriction is that you can not continue displaying stimuli WHILE an RT is being assessed. There are ways to deal with this--e.g., do you want to record the RT if they respond at some point during the mask? This gets much trickier when you want an RT to span multiple stimuli.