I'm working with a dataset for the Logan stop signal task (basically a type of reaction time task with a random subset of trials requiring that the particpant "stop" a prepotent response in the presence of an auditory stop signal)and am having trouble writing script that will analyze performance sequentially across trials. I want to know how previous trials influence responses on the following trials.
The data are organized in the data set below. I would like to take the average of the React variable (reaction time)on trial N-1 where trial N (trials where event = stop) and trial N-1 (event = Go). I would then like to compare these reaction times to responses on trials N + 1. Generally, I need to calculate an average of specific trials relative to performance on previous trials. The location of stops are random. Has anyone performed similar anaylses? Any suggestions/thoughts would be greatly appreciated. Thanks, Brian Subj Trial Cond Event React Key XX DUR 1 14 O go 306 68 N/A 200 1 15 X go 432 65 N/A 200 1 16 X stop N/A 320 N/A 250 1 17 O go 393 68 N/A 250 1 18 O go 523 68 N/A 250 1 19 X go 420 65 N/A 250 1 20 O go 447 68 N/A 250 1 21 O go 528 68 N/A 250 1 22 X go 604 65 N/A 250 1 23 X go 525 65 N/A 250 1 24 X stop N/A 320 N/A 300 1 25 O go 343 68 N/A 300 1 26 O go 389 68 N/A 300 1 27 X go 403 65 N/A 300 1 28 X go 480 65 N/A 300 1 29 O stop N/A 320 N/A 350 1 30 O go 450 68 N/A 350 1 31 O go 421 68 N/A 350 1 32 X stop 390 65 N/A 300 1 33 O stop N/A 320 N/A 350 1 34 O go 437 68 N/A 350 . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
