___________________________________________________________________________________________________________________ VISUAL STATISTICAL LEARNING II ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC last updated: 03-02-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 03-02-2022 Millisecond Software Millisecond Software thanks Turk-Browne et al. for providing the original stimuli! ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ The script "Visual Statistical Learning II" implements the procedure used by Turk-Browne et al (2005) to study the role of attention on the unprompted statistical learning of temporal relationships inherent in a visual presentation of shapes. Turk-Browne et al (2005) expand on research done by Fiser and Aslin (2002) (-> see Inquisit script "Visual Statistical Learning" that implements the procedure used by Fiser & Aslin). For a more detailed description: Turk-Browne et al (2005). The automaticity of visual statistical learning. Journal of Experimental Psychology: General, 134, 552-564. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are shown a sequence of 624 shapes, one shape at a time (at a presentation rate of 400ms each with a posttrialduration of 200ms), that are either green or red. The participant's task is to 1. attend to only one of the colored shapes (green or red, counterbalanced) and 2. press the Spacebar whenever a shape in the attended color repeats itself, regardless of how many shapes of the other color may have been inbetween the repeating shapes. The order of the shapes is carefully assembled and contains a repeated number of 4 shape triplets in green and red. In the Forced-Choice part of the experiment, the script pins the 4 familiar triplet pairs (ABC, DEF, GHI, JKL - from the sequence) for the attended and unattended color against 4 novel triplets (AEI, DHL, GKC, JBF, see Turk-Browne et al). These novel triplets are made up of shapes that have never directly followed each other during the sequence presentation. All shapes in the Forced-Choice task are presented in black. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 20 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'vsl_turkbrowne_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. attendstream: which letter sequence is the attended one (1 or 2) colorattend: which color is the attended one (1 = green, 2 = red) selectedletter: the letter selected in PART I stimulusitem: the first presented stimulus in PART I and PART II target_active: whether a target was active in PART I (1 = active; 0 = otherwise) rt_target: accumulated latencies (in ms) since the last target presentation in PART I (resets to 0 with each target presentation) pairing: which 6 shapes are presented/compared during PART II (and in which order) shape1 - shape6: the six shapes in PART II latency: the response time (in ms) part1: measured from onset of last presented stimu part2: measured from onset of task questions response: the response made by participant (SCANCODE of response button) 57 = spacebar press 2 => key "1" was pressed 3 => key "2" was pressed responseText: the character code of the response button pressed Note: for spacebar press (scancode 57), the field appears empty correct: the correctness of response (PART II: 1 = correct; 0 = otherwise) Hit: whether the response is counted as a Hit in PART I FA: whether the response is counted as a False Alarm in PART I (2) Summary data file: 'vsl_turkbrowne_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) hitrate: hit rate for detecting targets in the stream when a target was presented within the last 3s meanRT_hit: mean hit latency (in ms) for detecting targets in the stream when a target was presented within the last 3s SD_hit: standard deviation of hit latencies propcorrect_attend: proportion correct of forced choice trials for triplets in attended stream propcorrect_unattend: proportion correct of forced choice trials for triplets in unattended stream ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ PART1 & PART 2: 24 shapes (originals from Turk-Browne et al)* are divided into 12 green and 12 red shapes (assignment is randomly done for each participant). The 12 shapes in each color are then divided into 4 triplets: ABC, DEF, GHI, JKL PART I: Shape Sequence There are 2 individual shape sequences of 312 items that 1. get assigned to either the red shapes or the green shapes (counterbalanced) and 2. get interweaved randomly (with one constraint: remaining streams shouldn't differ by more than 6 shapes) for each participant. The result is the observed stream of 624 shapes. Each shape is presented for 400ms with a Stimulus Onset Asynchrony (SOA) of 600ms. Each of those 2 individual sequences were constructed such that 1. all triplets are presented 24 times 2. 6 of those 24 triplet repetitions double the last letter (e.g. ABCC, DEFF etc) -> 6 x 4 (# of triplets) = 24 extra letters, 3. no immediate repeats of triplets (e.g. ABCABC) 4. no repeat of triplet pairs (e.g. ABCDEFABCDEF) (24 (#repetitions) x 4 (#of triplets) x 3 (#of letters/triplet) + 24 extra letters = 312 letters in a sequence) Scoring of Responses: If the participant hits the spacebar within 3000ms (default, see Turk-Browne et al) of the onset of a target (=repeated shape in the attended color), the response is scored as a Hit. Any other responses outside of that responsewindow are scored as a False Alarm. Should a new target appear during the 3000ms responsewindow (and the participant has not responded to the first target), the responsewindow is updated for the new target and a possible response counts towards the new target. PART II: Forced-Choice In the Forced-Choice part of the experiment, the script pins the 4 familiar triplet pairs (ABC, DEF, GHI, JKL - from the sequence) for the attended and unattended color against 4 novel triplets (AEI, DHL, GKC, JBF, see Turk-Browne et al). These novel triplets are made up of shapes that had never directly followed each other during the sequence presentation. All shapes in the Forced-Choice task are presented in black. Participants get to view 2 sequences of 3 shapes each. Each shape is presented for default=400ms in the middle of the screen with a break of 1s inbetween sequences. Participants are asked to decide which one was the more familiar one (default TASK: press "1" for first, press "2" for second -> change keys under values). Each of the 16 triplet-pairings for the attended and unattended color is presented twice, once with the familiar sequence being presented first and once with the familiar sequence being presented second. The resulting 64 possible forced-choice tasks are selected at random. ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ Millisecond Software thanks Turk-Browne et al. for providing the original 24 stimuli in red, green, and black! see section Editable Stimuli ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ Instructions are not original to the task. They are provided by Millisecond Software as htm/html pages and simple page elements and can be edited either by changing the provided htm/html files or directly under Editable Instructions. To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac) or Notepad (Windows). ___________________________________________________________________________________________________________________ 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: SOA_shapepresentation: Stimulus Onset Asynchrony (SOA; in ms) in Part I (default: 600ms) Note: needs to be at least 400ms (=shape presentation time) waitforcedchoice: determines the pretrialpause (in ms) before the first shape triplets are shown in the forced-choice task (default is 1s) leftkey: the left key used to respond if the first sequence is more familiar (default: "1") rightkey: the right key used to respond if the second sequence is more familiar (default: "2") responsewindow: determines how long (in ms) after a target is presented a response is counted as a Hit (default: 3000ms)