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  • Description
  • Finds and replaces sequences of event codes in a .pos file if the delay between the 2 last event codes of the sequence is above or below a time threshold. This is useful for recoding sequences corresponding to too short or too long behavioral reaction time.

  • Usage
  • poschseqrt file_in.pos file_out.pos sampling_period time_threshold
    with :

    • file_in.pos : input event file to process (with extension).
    • file_out.pos : output event file (with extension).
    • sampling_period : sampling period of the signal (in ms).
    • time_threshold : time threshold (in ms) between the 2 last event codes of the sequence :
      if >0 : recoding if time interval > threshold.
      if <0 : recoding if time interval < threshold.

    This program uses an interactive input.The questions are as follows (questions (program) are italic, answers (user) are bold):
    number of events in the sequence to find:
    3
    event 1 of the sequence to find:
    1
    event 2 of the sequence to find:
    2
    event 3 of the sequence to find:
    100
    event 1 of the new sequence:
    1
    event 2 of the new sequence:
    21
    event 3 of the new sequence:
    100


  • Fields of parameter file and examples

  • Example
    • poschseqrt filein.pos fileout.pos 1 -500
      In this example, all sequences of successive events 1 – 2 – 100 will be replaced by the sequence 1 – 21 – 100, only when the time interval between events 21 and 100 is less than 500 samples (with a sampling rate of 1 ms, this means less than 500 ms). This can be useful to recode correct behavioral reponses with long enough reaction time; for instance: 1 is the warning stimulus, 2 the target stimulus and 100 the subject's response. In the new pos file, the target stimuli followed by a correct answer is now coded as 21 :
      myfile.pos mynewfile.pos
      7824 1 0 7824 1 0
      8009 2 0 8009 21 0
      8867 100 0 8867 100 0
      9087 1 0 9087 1 0
      9699 2 0 9699 2 0
      9840 1 0 9840 1 0


  • Comments


  • Current version
  • 1.02 06-01-2011

  • History
    • 1.01 13-08-2007 (PEA) : 1st documented version.
    • 1.02 06-01-2011 (PEA) : update to use cmake and free release of Elan. Merge of 2 programs : pos_change_eve (changes one event code) and pos_change_eve_fromfile (changes all event codes).


  • Files
  • $ELANPATH/bin/poschseqrt

  • See also
  • poscheve, poschseq, pos_change_eve_fromfile