___________________________________________________________________________________________________________________ SIMPLE ATTENTIONAL BLINK ___________________________________________________________________________________________________________________ Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 11-04-2013 last updated: 02-17-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-17-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a simple Attentional Blink design to study the temporary suppression of visual attention. Attentional Blink: Reduced Processing of a second target (T1) that follows in short succession of a first target (T1) The implemented design is inspired by: Raymond, J.E.; Shapiro, K. L.; Arnell, K. M. (1992) Temporary suppression of visual processing in an RSVP task: An attentional blink? Journal of Experimental Psychology: Human Perception and Performance, Vol 18(3), 849-860. and: Folk, C.L, Leber, A.B., Egeth, H.E. (2002). Made you blink! Contingent attentional capture produces a spatial blink. Perception & Psychophysics, 64, 741-753. Differences between script and Raymond et al (1992): 1. script uses constant stream length (see Folk et al, 2002) whereas Raymond et al (1992) used variable stream length 2. reduced number of T1 stream positions and a reduced number of T1-T2 lag positions 3. T2 Task: in Raymond et al (1992) T2 was an X that could either be present or active. In this script, T2 is an X or a Z. 4. screencolor and color of letters and targets differ from Raymond et al (1992) ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants see a stream of non-repeating 20 letters. One of these letters is a red. This is target T1. It appears at predetermined positions (here: streampositions 5 or 10, editable parameters). Another letter might be an X or a Z. This is called the T2 stimulus. The T2 stimulus appears after the T1 stimulus in the stream at predetermined lags (here: lags 1 or 7, editable parameters). At the end of the sequence, participants have to recall the red letter (T1) and decide whether they saw an X or a Z. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up takes app. 30 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'simpleattentionalblink_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) display.refreshrate: the refereshrate of the current monitor 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 such as feedback trials. Thus, trialnum may not reflect the number of main trials run per block. random_lettercolor: true (default): the regular letters in the stream will be assigned random colors. (with exception of T1_color/T2_color). See list.randomlettercolors for details false: the regular letters will be presented in the color specified under lettercolor t1_streamposition: holds the current temporal streamposition of the T1 stimulus t2_lag: holds the current T1-T2 lag (Note: lag = 1 => t2 is presented directly after t1) t2_streamposition: holds the current temporal streamposition of the T2 stimulus t1_stim: holds the name of the current T1 stimulus t2_stim: holds the name of the current T2 stimulus response: the participant's response (T1 task: openended response; T2 task: scancode for X (45) or Z (44)) correct: the correctness of the response (1 = correct; 0 = error) latency: the response latency (in ms) letter1- letter18: store the 18 letters in the letter sequence (letters other than T1 and T2) Note: the letters 1-18 are presented in random order + onsettime of the 20 stream variables (Note: in stimulusFRAMES, not ms) (2) Summary data file: 'simpleattentionalblink_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) random_lettercolor: true (default): the regular letters in the stream will be assigned random colors. (with exception of T1_color/T2_color). See list.randomlettercolors for details false: the regular letters will be presented in the color specified under lettercolor T1_meancorr_pos1lag1: proportion correct responses to T1 task with T1 pos1 = 5 and T2 lag1 = 1 T1_meancorr_pos1lag2: proportion correct responses to T1 task with T1 pos1 = 5 and T2 lag2 = 7 T1_meancorr_pos2lag1: proportion correct responses to T1 task with T1 pos2 = 10 and T2 lag1 = 1 T1_meancorr_pos2lag2: proportion correct responses to T1 task with T1 pos2 = 10 and T2 lag2 = 7 T2_meancorr_pos1lag1: proportion correct responses to T2 task with T1 pos1 = 5 and T2 lag1 = 1 T2_meancorr_pos1lag2: proportion correct responses to T2 task with T1 pos1 = 5 and T2 lag2 = 7 T2_meancorr_pos2lag1: proportion correct responses to T2 task with T1 pos2 = 10 and T2 lag1 = 1 T2_meancorr_pos2lag2: proportion correct responses to T2 task with T1 pos2 = 10 and T2 lag2 = 7 ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ - simple AB design with: 2 T1 streampositions x 2 T1-T2 lag positions x 2 T2 stimuli x 30 repetitions each = 240 trial sequences Practice Block - 16 practice trial sequences (same as test sequences but with error feedback) Test Block Set-Up: - 240 Trial Sequences - random selection of T1 streamposition/lag/T2 with equal distribution of the two T2 across the 4 conditions T1streampositions x t1-t2 lags (see lists under section Editable Parameters) - every 60 (default) trial sequences are followed by a rest trial (editable parameter) Trial Sequence: - Fixation cross presentation for parameters.fixationduration (editable value) - A stream of 20* (default) white (or randomly colored) letters are presented: letters are randomly selected without replacement - one of the letters in the stream is red (default) => T1 - one of the letters following the T1 is either an X or a Z => T2 -> participants are asked to recall the T1 at the end of the stream -> participants are asked to press X if T2 = X or press Z if T2 = Z !!! Note: LETTER PRESENTATION TIME The letter presentation duration in this script is coded in terms of stimulusframes. On a monitor with a vertical refresh rate of 60Hz, one stimulusframe ~16.7ms. Each letter in this script is presented for 1 stimulusframe (~16.7ms on a 60Hz monitor) with a blank stimulus interval of 5 stimulusframes (~83.3ms on a 60Hz monitor) ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ Items can be edited under EDITABLE STIMULI; Text sizes can be edited under EDITABLE PARAMETERS ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ Instructions are provided by Millisecond Software as htm/html pages and can be edited by changing the provided htm/html files. To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac) or Notepad (Windows). Additional instructions are listed 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: /restperiods: ratio of trialsequences to rests (aka there is a rest trial following every 60 trial sequences - default) Trialnumbers: / practiceTrials: the number of practice trials run (default: 16) / testTrials: the number of test trials run (default: 240) Streampositions and lags: / streampositionT1_1: streamposition1 tested for T1 (default: 5) / streampositionT1_2: streamposition1 tested for T1 (default: 10) / lagT2_1: lag1 tested for T2 (default: 1) / lagT2_2: lag2 tested for T2 (default: 7) Note: there are 20 streampositions total, thus 20 is the last position for T2. Duration variables (in ms): /restduration: duration of rest trial in ms (default: 60000ms) /fixationduration: duration of fixation cross in ms (default: 500ms) /responsecue_duration: duration of the response cue in ms (default: 500ms) <= not in original article Duration variables (in vertical refreshframes) /stimDuration: duration of letters (default: 1 frame) /isi: duration of interstimulus interval (default: 5 frames) !!!Note: on a 60Hz monitor the vertical refreshrate is ~16.67ms per stimulusframe => 1 frame ~ 16.67ms => 5 frames ~ 84ms Letter/targets: /stimulussize_letters: height of the letters relative to screen height (default: 10%) /random_lettercolor true: the regular letters in the stream will be assigned random colors. (with exception of parameters.T1_color/parameters.T2_color). See list.randomlettercolors for details false: the regular letters will be presented in the color specified under parameters.lettercolor /lettercolor: specifies the regular letter color if parameters.random_lettercolor == false /T1_color: specifies the color of T1 (default: red) /T1_color_label: the word label for T1 color (default: "RED") /T2_color: specifies a particular color for T2 (if left blank = "" => T2 gets the same color as regular stream letters) /responsekey_T2_1: response key 1 (default: 'X') /responsekey_T2_2: response key 2 (default: 'Z')