___________________________________________________________________________________________________________________ *Probabilistic Serial Reaction Time Task* ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 09-22-2020 last updated: 03-03-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 03-03-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a Probabilistic Serial Reaction Time Task. The implemented procedure is based on Kaufman et al (2010) Reference Kaufman, S.B et al (2010). Implicit learning as an ability. Cognition, 116, 321–340. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are presented 4 gray boxes arranged in a horizontal line and have to press a spatially corresponding response button as fast as possible once one of the boxes turns red. The sequence in which the box positions light up are controlled by two sequences: A and B. 85% of boxes follow sequence A; 15% of boxes follow sequence B. The transition btw. sequences respect the second-order conditionals of the upcoming sequence (see Kaufman et al, 2010, for an indepth discussion). The default task runs 8 test blocks of 120 trials each. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 25 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'probabilisticsrt_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 such as feedback trials. Thus, trialnum may not reflect the number of main trials run per block. (parameter) runFixedDesign: true (1): the script ran fixed (pre-determined) trial sequences for block1-block8 false (0): the script ran randomized trial sequences for each block (parameter) testprop_sequenceA: the frequency of test trials in a block for sequence A (parameter) testprop_sequenceB: the frequency of test trials in a block for sequence B Note: practice trials run with 50% seqA/seqB BlockCounter: counts the number of blocks run (resets after practice) TrialCounter_perblock: counts the number of trials run in a block sequence: "A" vs. "B": the sequence the current trial is running listIndex: the item index of list.sequenceA/list.sequenceB that is currently selected position: the position of the highlighted box that is selected by listIndex //DV: response: the participant's response (scancode of response buttons): 47 = V; 48 = B; 49 = N; 50 = M 57 = spacebar correct: accuracy of response: 1 = correct response; 0 = otherwise latency: the response latency (in ms); measured from: onset of highlighted box (2) Summary data file: 'probabilisticsrt_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) (parameter) runFixedDesign: true (1): the script ran fixed (pre-determined) trial sequences for block1-block8 false (0): the script ran randomized trial sequences for each block (parameter) testprop_sequenceA: the frequency of test trials in a block for sequence A (parameter) testprop_sequenceB: the frequency of test trials in a block for sequence B Note: practice trials run with 50% seqA/seqB //ACROSS ALL TEST BLOCKS propCorrect_seqA: proportion correct responses for sequence A trials meanCorrRT_seqA: mean correct response time (in ms) for sequence A trials propCorrect_seqB: proportion correct responses for sequence B trials meanCorrRT_seqB: mean correct response time (in ms) for sequence B trials //By BLOCK 1-8 propCorrect1_seqA: proportion correct responses for sequence A trials in block1 meanCorrRT1_seqA: mean correct response time (in ms) for sequence A trials in block1 (same for block 2-8) propCorrect1_seqA: proportion correct responses for sequence B trials in block1 meanCorrRT1_seqA: mean correct response time (in ms) for sequence B trials in block1 (same for block 2-8) * separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section "DATA" and follow further instructions ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 1. Practice: 20 practice trials (change under section Editable Parameters) - 50% sequence A and 50% sequence B trials - order is randomly determined - error feedback is provided - transitions btw. sequence A trials and sequence B trials respect the second-order conditionals of the upcoming sequence (Explanation below) 2. Test: by default, this script runs 8 blocks with predetermined sequences of sequenceA and sequenceB trials (see editable parameters for possible changes) - each block runs 120 trials - 85% of the trials are sequence A trials; 15% of trials are sequence B trials - transitions btw. sequence A trials and sequence B trials respect the second-order conditionals of the upcoming sequence (see Kaufman et al, 2010, for an indepth discussion) Example: sequence A: 1, 2, 1, 4, 3, 2, 4, 1, 3, 4, 2, 3 (see Kaufman et al, 2010) sequence B: 3, 2, 3, 4, 1, 2, 4, 3, 1, 4, 2, 1 (see Kaufman et al, 2010) If sequenceA has played the sequence '14' the next position would be '3' IF sequence A continued (14->3). A switch to sequence B would play position '2' instead as '2' follows '14' in sequence B (14->2). - after each block participants get a break of 30s (editable parameter) ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ 4 gray boxes - size and screen location can be edited under Editable Parameters ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ are not original to Kaufman et al (2010); edit 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: