Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Millisecond LLC thanks Turk-Browne et al (2005) for providing the 12 original shapes used in this study!
Last Modified: January 31, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
The script "Visual Statistical Learning I" adapts the procedure used by Fiser & Aslin (2002) to study the unprompted statistical learning of temporal relationships inherent in a visual presentation of moving shapes:
Fiser, J. & Aslin, R.N. (2002). Statistical Learning of Higher-Order Temporal Structure from Visual Shape Sequences. Journal of Experimental Psychology: Learning, Memory, and Cognition, 28, 458-467.
10 minutes
Participants are presented with a 5-6min "movie", in which 12 basic shapes moved one after the other across the monitor from, seemingly "changing" from one shape into another when they cross a black bar in the center of the screen. The "change", however, is not random as the 12 shapes were grouped into 4 triplets with strict rules regarding to which shape can follow another, e.g. triplets have to stay together and have to be presented always in the same order (A->B->C). To test whether participants have learned the inherent temporal shape relationships, the movie-triplets (=familiar) are pinned against "novel" triplets in a balanced forced-choice task, in which participants are asked to decide which of the two triplet pairs are more familiar to them.
PART I: Shape Sequence "Movie":
This script implements a simple imitation of the original movie used by Fiser & Aslin (2002).
In Fiser and Aslin's study, participants watched a shape appear from under a black bar that was positioned
in the middle of the screen. The shape then moved to the left of the screen, changed direction and moved back
towards the bar, behind which it disappeared once more. When it "reappeared", the shape had "morphed"
into the next shape, which stayed on the same trajectory and moved to the right side of the screen,
changed direction and moved back towards and behind the bar again (and so on). Each shape was presented for 1s.
The underlying shape sequence in this script meets the same criteria used by Fiser & Aslin (2002):
(1) 12 shapes divided into 4 triplets
(2) Triplets stay together
(3) Each triplet is presented 24 times (=288 shape presentations)
(4) No immediate repeats of triplets (e.g. ABCABC)
(5) No repeat of triplet pairs (e.g. ABCDEFABCDEF)
(6) Each triplet appears the same number of times in each third of the sequence (8times)
In addition, this script offers the opportunity to randomly
(1) select from a pool of 10 possible sequences that all meet these criteria. (=> vary sequence across participants)
(2) assign the 12 shapes to the 4 triplet pairs (=> triplet pairs are not constant across participants)
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) against 4 novel triplets (AEI, DHL, GKC, JBF)*.
These novel triplets are made up of shapes that had never directly followed each other during the
sequence presentation - changes to these triplets can be made under trial.assignments (e.g. change triplets to
partial triplets as used in Fiser & Aslin (2002), Experiment2).
Participants get to view 2 sequences of 3 shapes. Each shape is presented for default=500ms**
with a break of 1s (s. Fiser & Aslin).
Shapes appear in a left- right-left sequence (s. Fiser & Aslin). Participants are asked to decide
which one is more familiar.
(default TASK: press "1" for first, press "2" for second -> change keys to press under values).
Each of the 16 triplet-pairings is presented twice, once with the familiar sequence being presented
first and once with the familiar sequence being presented second. The resulting 32 possible
forced-choice tasks are selected at random.
•Fiser & Aslin (2002) do not specify the novel triplet combinations used.
The triplet combinations used in this script are taked from Turk-Browne et al (2005).
The automaticity of visual statistical learning. Journal of Experimental Psychology: General, 134, 552-564.
Millisecond LLC thanks Turk-Browne et al (2005) for providing the 12 original shapes used in this study!
See section Editable Stimuli
Instructions are not original to the task. They are provided by Millisecond
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).
File Name: vsl_fiser_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| propCorrect | Proportion correct familiar triplet identifications |
| meanRTCorrect | Mean latency (in ms) of correct familiar triplet identifications |
| sdCorrect | Standard deviation (in ms) of correct familiar triplet identification latencies |
File Name: vsl_fiser_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockCode | Name of the current block |
| blockNum | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| list.tripletSequence.currentIndex | The index of the selected tripletsequence (e.g. the third sequence in the list) |
| selectedLetter | The letter presented in the shape presentation sequence |
| inde | The letter position in the shape presentation sequence |
| a-l | The indices of the shapes (from the item list shapes) that are assigned to shapes a-l |
| novel11-novel43 | The indices of the shapes (from the item list shapes) that are assigned to novel triplets |
| pairing | Determines which familiar and which novel triplets were compared and in which order (e.g. 15 -> triplet pair ABC against novel triplet 1, familiar first) 15 = old ABC triplet, novel1 triplet 51 = novel1 triplet, old ABC triplet ... 48 = old JKL triplet, novel4 triplet 84 = novel4 triplet, old JKL triplet |
| shape1-shape6 | The shapes presented during the forced-choice trials with shape 1 being the first |
| response | The SCANCODE of the key-response of the participant 2 (scancode) => number '1' (first sequence more familiar) 3 (scancode) => number '2' (second sequence more familiar) |
| responseText | The character code of the key pressed |
| correct | Whether this is a correct response (1= correct; 0 = error) |
| latency | How long the participant took to make response (in ms); measured from onset of task question |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| waitForcedChoice | Determines the pretrialpause 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") |