GNAT - No Response as Valid

Location:

…\DirectRT\samples\6- v2006\no response as valid

…\DirectRT\samples\6- v2006\gnat

Sample Descriptions

You can use -1 as a keycode to represent "no response" as if it were just like any other keypress. That means you can list it with other keycodes, either first to indicate it's the correct answer or later in the list to indicate that it's incorrect. If the subject waits as long as the max value in the MinMax field of the style for that stimulus then that's like pressing the "-1" key.

The first sample input file "noresponse.csv" in the "no response as valid" folder shows how to do this in the simplest way possible:

~no response	0,0,1	rt:-1,57
~hit space	0,0,1	rt:57,-1

Here we see that no response is correct for the first trial, and hitting the space bar is correct for the second.

GNAT

The GNAT sample files in the "gnat" folder are the DirectRT version of the Go/No-go Association Task (GNAT) posted at Project Implicit (see http://projectimplicit.net/nosek/gnat/)

In them, you'll see:

rt:57,-1<-999

rt:-1,57<-999

57 as usual is the keycode for the spacebar. -1 is the new code used to represent no response. <999 normally means jump to trial 999 when the trial is over and then resume. If you add a negative sign as in <-999, DirectRT will jump RIGHT AWAY without finishing the trial. The subject never sees the rest of the trial. Trial 999 is the X. So if you don’t jump immediately to 999 (and get the X) then you get the O which is at the end of each trial.

Note: see http://www.empirisoft.com/support/showthread.php/94-Min-max-values-being-ignored for notes regarding a bug that had the potential to affect the 'no response' option in versions 2006.1.12 - 2006.1.15.