___________________________________________________________________________________________________________________ FACE IN THE CROWD (FITC) DEMO ___________________________________________________________________________________________________________________ Script Author: Millisecond Software, LLC last updated: 02-22-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-22-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script offers example code to 1) determine the relative coordinates of target locations (->block.determinecoordinates) 2) select locations in an image: FITC task (-> block.fitc) The default is to run the FITC task. An editable variable (parameters.taskselection) can be set to run either task. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are asked to select target faces in a picture depicting a crowd of people. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 1 minute to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'faceinthecrowd_demo_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) date, time: date and time script was run subject, group, with the current subject/groupnumber session: with the current session id 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. target: the presented stimuli in order of trial presentation response: the participant's response correct: the correctness of the response latency: the response latency (in ms) percent_horizontal_targetx: stores the percent (of canvas) of the horizontal target coordinate percent_vertical_targety: stores the percent (of canvas) of the vertical target coordinate percent_response_x: stores the percent (of canvas) of the x coordinate of the response percent_response_y: stores the percent (of canvas) of the x coordinate of the response (2) Summary data file: 'faceinthecrowd_demo_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) 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) list.ACC.mean: Overall proportion correct selections list.RT.mean: Overall mean latency (in ms) of correct selections ___________________________________________________________________________________________________________________ TASK: DETERMINE THE RELATIVE COORDINATES OF THE TARGET LOCATIONS (->block.determinecoordinates) ___________________________________________________________________________________________________________________ 1) Set your canvas under DEFAULTS. This is important as not all monitors are the same size. Forcing a canvas on each monitor will keep the relative screen positions of the targets the same. 2) Force a picture size to ensure that the picture takes up the same relative canvas location on each monitor 3) create a trial that calculates the relative screen locations by using the x/y-coordinate of the mouse cursor at the end of the trial, at the time of 'lbuttondown' (trial.determinecoordinates) Stores the coordinates in the data file. 4) manually fill in the target coordinates into list.hposition and list.vposition under LISTS. Make sure that the index of the coordinates corresponds to the index of the target image in item.targetfaces. EXAMPLE: if the target image is 'Face03.jpg' and it is stored under index '/3 = "Face03.jpg"' in item.targetfaces then make sure to store the corresponding coordinates as the third items in list.hposition and list.vposition II) "Face in the Crowd" Task: FITC (-> block.fitc) ___________________________________________________________________________________________________________________ TASK: FIND PARTICULAR FACES IN A CROWD ___________________________________________________________________________________________________________________ Steps: 1) Make sure the script runs the same /canvassize to run block.fitc as was used to determine the target coordinates 2) The relative coordinates of the targets are used to define response circles (-> shape.responsecircle). Check out shape.responsecircle for more details 3) Present these response circles BEFORE the crowd image, so that the crowd image covers response circles on the screen. (FACE IN THE CROWD MAIN TRIALS-> trial.faceinthecrowd -> stimulusframes) Note: To check/debug the positions of the response circle: present the response circles AFTER the crowd image (aka superimpose the circles onto the pictures) 4) Ask participants to click on the target faces in the crowd image. If they click on the underlying response circles, the response is evaluated as 'correct'; if not the response is evaluated as 'incorrect'. ___________________________________________________________________________________________________________________ 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: /taskselection: 1 = determine coordinates of the targets and have the coordinates saved as screen percentages in the datafile 0 = run the task of finding the faces the crowd (FITC) (default)