Visual Search

From PEBL WIKI
Jump to: navigation, search
Screen shot of PEBL's Visual Search Task

Contents

[edit] About

[edit] Notes

[edit] Options

Within the vsearch.pbl file, there are some ways to edit/control the conditions:

  targs  <- ["O","X"]
  foils <- ["U","D","G","C","Q"]
  foilcolor <- MakeColor("white")
  searchsize <- [10,20,30]
  numtargs <- [0,1,5]
  targcols <- ["white","green"]   
  reps  <- 5

The design will fully cross search targs, size, numtargs, targcols, and reps. So by default, we have 2x3x3x2x5=180 trials. Foils should not include any of the targets.

[edit] Data Output

Example data output:

sub,trial,time,numtargs,size,targchar,targcol,stim,resp,corr,rt1,rt2
3,1,2843,1,20,X,green,XGUCQDUQGDCGQCUDQGUD,1,1,1041,1231
3,2,6008,1,30,X,white,XGUDCQUDGCQUDQCGUGCQDUDQCGUCGD,1,1,950,1138
3,3,9213,1,30,X,green,XUCQDGDUQGCUCQGDQDGCUGQDCUDCQU,1,1,488,1107
3,4,11891,1,10,X,green,XQUCDGUQDG,1,1,520,933
3,5,14197,5,20,O,green,OOOOOQGDCUQGCDUGUCQD,3,1,562,885
3,6,16582,5,30,X,green,XXXXXQGUDCQUDGCDUCQGUQCDGDGCQU,4,1,1280,698
3,7,19786,5,20,O,white,OOOOOGDCQUCQUDGDQUGC,3,1,488,1287
3,8,22435,0,20,X,white,DGUCQGUCDQCUDGQGDUCQ,0,1,492,2122

These are:

  • sub: subject code
  • trial: trial number
  • time: absolute time, in ms, when the trial started.
  • numtargs: how many targets appeared
  • size: How many stimuli were on the screen
  • targchar: the target charactr
  • targcol: the target color (foil colors were always white)
  • stim: list of all the stimuli that appeared, including targets (locations are not saved)
  • resp: response made; 0='none'; >0; a target (number indicates which target)
  • corr: whether the response was correct
  • rt1: time to click (search time)
  • rt2: time to respond after click (move mouse to target)

[edit] References

Treisman, A. (1985). Preattentive processing in vision. Computer Vision, Graphics, and Image Processing, 31(2), 156-177.

[edit] See Also

PEBL Test Battery

Personal tools
Namespaces

Variants
Actions
Navigation
Toolbox