___________________________________________________________________________________________________________________ Line Bisection Task ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 01-16-2023 last updated: 01-23-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 01-23-2023 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements Millisecond Software's computerized version of the Line Bisection Task (e.g. Nash et al, 2010), a behavioral measure of relative cerebral hemisphericity. The default setup for the Millisecond Software Line Bisection Task is optimized for touchscreen devices sized like an ipad but adapts to mouse use on non-touchscreens. By default, the stimuli are absolutely sized if the current screen size is big enough - if not, the script uses the largest 4:3 portion of the current screen (e.g. smartphone screen) that it can find. Absolute sizing of stimuli can easily be turned off or fine-tuned via parameter settings. References: Nash, K., Mcgregor, I., & Inzlicht, M. (2010). Line bisection as a neural marker of approach motivation. Psychophysiology, 47(5), 979–983. https://doi.org/10.1111/j.1469-8986.2010.00999.x Jewell, G.,&McCourt, M. E. (2000). Pseudoneglect: A review and metaanalysis of performance factors in line bisection tasks. Neuropsychologia, 38, 93–110. Savazzi, S., Posteraro, L., Veronesi, G., & Mancini, F. (2007). Rightward and leftward bisection biases in spatial neglect: two sides of the same coin? Brain (London, England : 1878), 130(8), 2070–2084. https://doi.org/10.1093/brain/awm143 ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ This task presents up to 14 (staggered) lines on the same page. The number of lines and the length as well as horizontal screen position of each line can be set via parameter settings. By default, this script presents 6 staggered lines of different lengths. Participants are asked to touch/click the midpoint of each line to place a midpoint marker. Once all lines have been marked, participants can press a 'Done' button. Participants can correct the position of the midpoint markers until they click the 'Done' button. Participants are instructed NOT to measure the lines. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 3 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'linebisectiontask_raw*.iqdat' (a separate file for each participant) build: The specific Inquisit version used (the 'build') that was run computer.platform: the platform the script was run on (win/mac/ios/android) computer.touch: 1 = the screen is a touchscreen; 0 = otherwise date, time: date and time script was run subject: with the current subject id group: with the current group id session: with the current session id //Screen Setup: (parameter) runAbsoluteSizes: true (1) = should run absolutely sized canvas (see parameters- canvasHeight_inmm) false (0) = should use proportionally sized canvas (uses width = 43*screenHeight) canvasAdjustments: NA: not applicable => parameters- runAbsoluteSize was set to 'false' 0: parameters- runAbsoluteSize was set to 'true' and screen size was large enough 1: parameters- runAbsoluteSize was set to 'true' BUT screen size was too small and adjustments had to be made activeCanvasHeight_inmm: the width of the active canvas (by default: lightGray area) in mm activeCanvasWidth_inmm: the height of the active canvas in mm display.canvasHeight: the height of the active canvas in pixels display.canvasWidth: the width of the active canvas in pixels px_per_mm: the conversion factor to convert pixel data into mm-results for the current monitor (Note: the higher resolution of the current monitor the more pixels cover the same absolute screen distance) This factor may be needed if you want to convert pixel data into mm data blockcode, blocknum: the name and number of the current block (built-in Inquisit variable) trialcode, trialnum: the name and number of the currently recorded trial (built-in Inquisit variable) Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those that do not store data to the data file. //built-in DVs: response: the response of participant (scancode of response button) latency: response latency (in ms); numberOfLines: the number of lines presented lineHeight_inmm: the lineHeight in mm distance_btw_lines_inpct: the proportional distance (relative to canvas height) between the lines - measured from midpoints distance_btw_lines_inpx: the pixel distance of the lines (Note: pixel measures vary from screen to screen) distance_btw_lines_inmm: the distance in mm between the lines (measured from) ////////////////////// Individual Lines Data ////////////////////// Note: the final data is provided in trial.bisection_end //////Line1////// line1_length_inpct: length of line1 in canvas width percent line1_length_inpx: length of line1 in screen pixels line1_length_inmm: length of line1 in mm line1_midx_inpct: the horizontal coordinate of the midpoint of line1 in canvas width percent line1_midx_inpx: the horizontal coordinate of the midpoint of line1 in pixels line1_marker_x_inpx: the horizontal coordinate of the marker placed on line1 in pixels line1_diff_inpx: the PIXEL difference (depends on monitor) in horizontal coordinates of line1 and marker Negative values: the marker was placed left to the midpoint line1_diff_inmm: the mm difference (absolute measurements) in horizontal coordinates of line1 and marker Negative values: the marker was placed left to the midpoint Note: calculations of mm differences make use of Inquisit's built in conversion functions (same for the remaining lines) /////////////////////// //line failure data:/// /////////////////////// lineFailure: 1 = the settings for all to-be-presented lines work; 0 = the settings for at least one line do not work checkLine1 - checkLine14: stores the individual notes left for each line (1 = no problem) (2) Summary data file: 'linebisectiontask_summary*.iqdat' (a separate file for each participant) inquisit.version: Inquisit version run computer.platform: the platform the script was run on (win/mac/ios/android) computer.touch: 1 = the screen is a touchscreen; 0 = otherwise startDate: date script was run startTime: time script was started subjectid: assigned subject id number groupid: assigned group id number sessionid: assigned session id number elapsedTime: time it took to run script (in ms); measured from onset to offset of script completed: 0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run) //Screen Setup: (parameter) runAbsoluteSizes: true (1) = should run absolutely sized canvas (see parameters- canvasHeight_inmm) false (0) = should use proportionally sized canvas (uses width = 43*screenHeight) canvasAdjustments: NA: not applicable => parameters- runAbsoluteSize was set to 'false' 0: parameters- runAbsoluteSize was set to 'true' and screen size was large enough 1: parameters- runAbsoluteSize was set to 'true' BUT screen size was too small and adjustments had to be made activeCanvasHeight_inmm: the width of the active canvas (by default: lightGray area) in mm activeCanvasWidth_inmm: the height of the active canvas in mm display.canvasHeight: the height of the active canvas in pixels display.canvasWidth: the width of the active canvas in pixels px_per_mm: the conversion factor to convert pixel data into mm-results for the current monitor (Note: the higher resolution of the current monitor the more pixels cover the same absolute screen distance) This factor may be needed if you want to convert pixel data into mm data //////Summary Data////// numberOfLines: the number of lines to be bisected ////overall///// numberErrors: number of Error placements //Note: any pixel difference <> 0 is counted as an error in this script propErrors: proportion of errors (relative to number of lines) propLeftError: proportion of left (to midpoint) placed errors (relative to the number of errors made) meanDiff_inpx: mean PIXEL difference btw. line midpoints and placed marker meanDiff_inmm: mean mm difference btw. line midpoints and placed marker (= pixel mean converted into mm using Inquisit built-in functions) //individual line summary data://// //Negative values: the marker was placed left to the midpoint //Calculations of mm differences make use of Inquisit's built in conversion functions line1_length_inpx: length of line1 in screen pixels line1_length_inmm: length of line1 in mm line1_resps: number of times the line1 marker was placed line1_diff1_inpx: PIXEL difference btw. line1 midpoint and placed marker for FIRST marker placed (pixel differences depend on monitor) line1_diff_final_inpx: PIXEL difference btw. line1 midpoint and placed marker for FINAL marker placed line1_meanDiff_inpx: mean pixel difference btw. line1 midpoint and all placed markers on line1 line1_diff1_inmm: mm difference btw. line1 midpoint and placed marker for FIRST marker placed (absolute measurements) line1_diff_final_inmm: mm difference btw. line1 midpoint and placed marker for FINAL marker placed (= submitted marker) line1_meanDiff_inmm: mean mm difference btw. line1 midpoint and all placed markers on line1 (same for line2-line14) Note: data fields will be empty for lines that are not run ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ (1) Block: LineCheck This block checks that the parameter settings for each of the to be presented lines work. If a violation is detected (e.g. the line is too long for the placement of the midpoint), the script terminates. The raw data file will contain information about the lines that need to be updated. (2) Line Bisection Task 1-14 horizontal lines are presented on the same page using the parameter settings for: - line lengths - line placements (horizontal midpoints) The script automatically calculates the vertical distance between the lines depending on how many lines should be placed on the screne. For Example, if only 1 line is presented it is presented in the vertical center of the screen. By default, this script presents 6 of the possible 14 lines. Participants are asked to place a marker on a each of the lines to bisect them. All markers have to be placed before a 'Done' button appears. Participants can correct the marker placements as many times as needed. ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ provided by Millisecond Software - number of lines, their length (and width) as well as horizontal canvas placement can be configured under section Editable Parameters ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ provided by Millisecond Software - can be edited under section 'Editable Instructions' ___________________________________________________________________________________________________________________ EDITABLE CODE ___________________________________________________________________________________________________________________ check below for (relatively) easily editable parameters, stimuli, instructions etc. Keep in mind that you can use this script as a template and therefore always "mess" with the entire code to further customize your experiment. The parameters you can change are: