___________________________________________________________________________________________________________________ DICHOTIC LISTENING TASK (DIGITS) ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 04-03-2012 last updated: 02-21-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-21-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a variant of the dichotic listening task to study selective auditory attention. The implemented procedure uses digits. Reference: Koch, I., Lawo, F., Fels, J. & Vorlaender, M. (2011). Switching in the Cocktail Party: Exploring Intentional Control of Auditory Selective Attention. Journal of Experimental Psychology: HPP, 37, 1140 - 1147 ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants listen to 2 digits (1-9, no 5) simultaneously played in the left and the right ear, one spoken by a female and the other by a male voice. In each trial a colored cue (here: @) signals which of the two genders presents the target digit. The task is to decide if the target digit is less than or greater than 5. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 28 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'dichoticlistening_digits_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. group: color assignments to female/male 1: female = yellow; male = green 2: female = green; male = yellow parameters.smallerkey/largerkey: the scancode for the "smaller"/"larger" keys parameters.colorname1/colorname2: hold the NAME of the two colors blockcount: counts the experimental blocks run expcondition: the experimental condition run: 0 = starttrial; 1 = switch-congruent (sc); 2 = switch-incongruent (sic); 3 = repeat-congruent (rc); 4 = repeat-incongruent (ric) genderattention: 1 = pay attention to female voice; 2 = pay attention to male voice gender_left/gender_right: the gender of the voice in the left/right ear, 1 = female; 2 = male digit_left/digit_right: the digits to play in each ear left_index/right_index: the index number of the left/right soundfile to be played response: the participant's response (e.g. scancode of response button) 16 = Q (left) 25 = P (right) correct: the correctness of the response (1=correct; 0 = error) latency: the response latency (in ms) (2) Summary data file: 'dichoticlistening_digits_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) propCorrect_overall: overall proportion correct across the 4 experimental conditions meanRT_overall: mean correct response time (in ms) across the 4 experimental conditions propCorrect_SC: proportion correct in condition sc (shift, congruent) meanRT_SC: mean correct response time (in ms) in condition sc (shift, congruent) propCorrect_SIC: proportion correct in condition sic (shift, incongruent) meanRT_SIC: mean correct response time (in ms) in condition sic (shift, incongruent) propCorrect_RC: proportion correct in condition rc (repeat, congruent) meanRT_RC: mean correct response time (in ms) in condition rc (repeat, congruent) propCorrect_RIC: proportion correct in condition ric (repeat, incongruent) meanRT_RIC: mean correct response time (in ms) in condition sic (repeat, incongruent) ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ * 2 levels of auditory attention switch (switch vs. repeat) x 2 levels of congruence of digits (congruent vs. incongruent) => 4 experimental conditions (1) Auditory Attention Switch: tested within Switch: if participant had to pay attention to male (female) channel in previous trial, participant is asked to pay attention to female (male) channel for the current trial Repeat: pay attention to the same gender in the current trial (2) Congruence: tested within Congruent: both digits are less (greater) than 5 Incongruent: one digit is greater and one is less than 5 * Color Assignments counterbalanced by groupnumber BLOCKS: (1) Experimental: 4 blocks * each block runs 1 starttrial + 144 experimental trials (36 per experimental condition) (starttrial is excluded from analyses, it cannot be one of the 4 experimental conditions as it can neither switch nor repeat) (2) Practice: short version of the Experimental condition: 1 starttrial + 24 experimental trials (no data recorded) TRIAL COMBOS: trial.switch_congruent, trial.switch_inconcruent, trial.repeat_congruent, trial.repeat_incongruent (trial.starttrial)-> trial.response * present a large @ sign in green and yellow (default) that signal to pay attention to male or female voice (counterbalanced for color-gender assignment) (by default there is a 800ms pretrialpause before the cue comes on, and the cue stays on for 500ms before the digits are spoken) * determine gender to be attended according to experimental condition * randomly assign gender to the left and right channel * randomly select a digit for the left ear and depending on experimental condition, randomly select from the congruent or incongruent options for the right ear (excluding same digits for congruent condition, e.g. you cannot have "2" spoken in the left and right ear) * randomly select one of the three soundfiles for each ear depending on digit and assigned gender * sum up reaction times of correct responses and calculate corresponding mean (DV), separately for each condition These data are recorded in the summary data file. * errorfeedback for 1000ms !!!NOTE!!!: Koch et al (2011) not only excluded the reaction times of the starttrials and reaction times of incorrect trials but also excluded reaction time of trials with reaction times that exceed 3STDs of the mean. This script simply excludes data from starttrials as well as reaction times of incorrect trials. ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ *3 soundfiles per digit per gender (3 different voices) = 2 * 3 * 9 = 54 (minus 6 soundfiles for digit 5 that are included for algorithm purposes only) !!!NOTE!!!!: the script has the necessary set-up to support using 3 sounfiles per gender per digit, however, at this point only one actual soundfile per gender per digit is included. To add the remaining soundfiles go to Stimuli Item.digitsounds. ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ provided by Millisecond Software in the form on images- 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: cuepresentation: the duration of the cue before the soundfiles are played in ms (default: 500) pre_cuepresentation: the pause before the cue comes on in ms (default: 800) smallerkey/largerkey: the scancode for the "smaller" (Q)/"larger" keys (P) color_1/color_2: the colors associated with gender Note: Assignment is counterbalanced by groupnumber colorname1/colorname2: string variables that holds the NAME of the two colors Note: if you change the colors and/or key scancodes, you need to make appropriate changes to item.intros