Sunday, December 4, 2011

MEGANTI - Preprocessing

[Presentation sce file]
In total 14 blocks, each block has 80 trials, each trial has following four events recorded in the log file:

  1. [Start]: duration 1000 ms, code 0, port_code 1
  2. [Pro] or [Anti] initiation: LightOn, (green pro, red anti) duration 100 ms, code 54, port_code 54, 
  3. [pro5xxx] or [anti5xxx]: randomized length, code: 5+ [100:50:1000], e.g. 5100, 5250..., port_code [101:1:117]
  4. [GO cue ∈ 1 | 2 | 3 | 4] :  duration 20 ms, LightOff
    • 1: greyboxproleft, port_code 201 -- prostim left
    • 2 :greyboxproright, port_code 202  -- prostim right
    • 3: greyboxantileft, port_code 203 -- antistim left
    • 4: greyboxantiright, port_code 204 - -- antistim right
Therefore(in preprocessing_subject.m), the duration of instruction (green or red box) = 100 ms (initiation) + x ms (x is indicated by event2 in matlab code).  The actual difference between light on and off is around 117-119 ms with some trials had more than 135 ms lag (var: timeLag).


Subjects
SW - [2010-08-11] - Old system no parallel code
raw: S02_MEG54_VEF_02.ds
stim log (raw): sw32-110810-SO2-Pro+Anti-saccade task.log
Problems in the data:
  1. The stim log has 195 missing event condition, all replaced with -1.
  2. The lightOn marker has 130 extra double triggers - fixed (lightOnTimeClean:1121)
  3. The lightOff marker has 3 extra  double triggers - fixed (lightOffTimeClean:1120)
  4. Verify by comparing the time diff between on and off with the event code, 121.40 

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