PEBL Continuous Performance Test

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Screen shot of PEBL's Continuous Performance Test


[edit] About

The pcpt directory of the test battery offers two related continuous performance tasks. The pcpt.pbl task is a faithful implementation of Conners's Continuous Performance task (CCPT). A constant series of letter stimuli appear on the screen; participant must respond to all stimuli EXCEPT the X. The pcpt-ax.pbl is an implementation of the CPT-AX task, modeled after one used by Lee and Park (2006). In this task a response is made ONLY when X follows A.

This is a vigilance task, which takes approx 14 minutes to complete. 360 letters approx 1 inch in size are presented one at a time. Participant must respond by pressing the space bar to all stimuli except the X.

[edit] Notes

Located in battery/pcpt/pcpt.pbl x

[edit] Options: PCPT

The default parameters reflect the Connors task faithfully.

  • testtype (Default=1) Type of test. Currently, only type 1 is implemented.
  • cycles (Default=6). Total number of blocks. cyclesxblocksize is the number of trials
  • blocksize (Default=20). Number of trials per block
  • prestime (Default=250). Presentation time of stimuli
  • targprob (Default=0.1). Probability of an 'x' target being presented
  • givefeedback (Default=0). Give text-based feedback about
  • pausebetweenblocks (Default=0). Whether a pause should occur between each ISI block
  • proportionalfoil (Default=1). if set to 1, will use exactly 1-targprob foils; if set to 0, will generate a foil with 1-targfoil probability on each trial

[edit] Options: pcpt-ax

  • cycles (Default=6) Total number of blocks. cyclesxblocksize is the number of trials
  • blocksize (Default=20) Number of trials per block
  • isi (Default=5000) Time between stimuli
  • prestime (Default=250) Presentation time of stimuli
  • axprob (Default=0.7) probability of a AX trial.
  • bxprob (Default=0.1) probability of a BX trial
  • ayprob (Default=0.1) probability of a AY trial
  • byprob (Default=0.1) probability of a BY trial
  • givefeedback (Default=0) Whether to give error feedback
  • pausebetweenblocks (Default=0) should they pause between blocks of trials?

[edit] Data Output

Detailed data is stored in data/subnum/ptpt-subnum.csv, and pooled across subjects in data/pooled-pcpt.csv. Detailed summary report is in data/subnum/pcpt-report-subnum.txt. This contains a number of summary statistics broken down across ISI. For cpt-ax, identical files named pcpt-ax are saved.

[edit] References

C. Keith Conners, Jeffery N. Epstein, Adrian Angold, John Klaric (2003) Continuous performance test performance in a normative epidemiological sample Journal of Abnormal Child Psychology,

[edit] See Also

PEBL Test Battery

TOAV: Test of Attentional Vigilance

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