Contextual Cueing Task

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Created: January 29, 2020

Last Modified: January 21, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements the Contextual Cueing Task (Chun et al, 1998), a task that aims to understand how contextual information influences visual attention.

References

Chun, M.M. and Jiang, Y. (1998) Contextual cueing: implicit learning and memory of visual context guides spatial attention. Cognit. Psychol., 36, 28–71

Duration

40 minutes

Description

Participants see displays of 11 "L" and one "T" (the target). The 12 items are presented within a 8x6 matrix in in four different colors (red, green, blue, yellow). Distractor items can be rotated by 0, 90, 180 or 270degrees. The target T can be rotated by 90deg (-> points to the right) or by 270degrees (-> points to the left). Participants have to press a left key (here: A) if the T points to the left and a right key (here: L) when the T points to the right.

Procedure

(1) Practice
- 24 trials (practice trials show unique scenes)

(2) Test: 30 blocks (a set of 5 consecutive blocks is grouped into one 'epoch' -> a total of 6 epochs is run)
- each block runs 12 OLD scenes and 12 NEW scenes (24 trials)
- at the end of each block participants are given a minimum of 10s to rest

Trial Sequence:
- fixation cross for 500ms
- display 'scene' until response
- correct/errorfeedback via soundfiles
- intertrial interval for 1000ms


Explanation of scene (and their generation):

Scene:
- 12 items (1 target + 11 distractors) located in a 8x6 matrix (each generated scene uses a UNIQUE spatial configuration for the items)
=> items appear in each 8x6 location, slightly jittered from the center
- 4 colors: red, green, blue, yellow (each color appears 3 times in each scene)
- target (T) is either oriented 90degress to the left (=270degrees) or 90degrees to the right (randomly determined for each trial)
- distractors (L) can be rotated by 4 angles (0, 90, 180, 270deg)


Old Scenes:
- 12 old scenes generated at beginning of the script - they are repeatedly used throughout the experiment
- the target appears in a different position for each of the 12 scenes
- the target appears equally often in each color
- The old scenes stay the same each time they are presented throughout the experiment:
same locations for targets/distractors, same color for targets/distractors, same angles for distractors
EXCEPT for the angle of the target (that is randomly decided each time the scene is presented)

New Scenes:
- targets appear in 12 dedicated locations
=> the same 12 target locations for NEW targets are used in each block
(the colors of the targets in those locations also stay the same across the experiment)
( 12 locations are assigned to OLD scenes, different 12 locations are assigned to NEW scenes)
- distractor positions change from scene to scene (this is the defining difference to OLD scenes)
- distractor colors change from scene to scene


Algorithm to generate unique scene locations/configurations:
- establish the target location
- then randomly sample the distractor locations out of the remaining 47 possible locations
- order the locations from smallest to largest
- check if this 'configuration' has been used before
- if used before: repeat process until a unique spatial configuration has been found OR
1000 unsuccessful attempts have been made (in this case values.repeatConfigurations will be set to 1)

Color Assignment (red, green, yellow, blue):
- across one block: the target appears in each color three times in the New configurations
- across one block: the target appears in each color three times in the Old configurations
=> across one block of 24 trials: the target appears in each color 6 times

Angle Assignment:
- Targets: for each trial it is randomly (with replacement) decided whether the target angle is 90 degree (left) or 270 degrees (right);
this is the case for Old and New configurations ( the target can have different rotation angles in the same Old scene)
- Distractors: each distractor gets randomly (with replacement) assigned angle of 0, 90, 180, or 270 degrees
=> each angle has the same probability to be sampled (frequencies of angles will likely vary)

Stimuli

provided by Millisecond - can be edited under section Editable Stimuli

Instructions

provided by Millisecond - can be edited under section Editable Instructions

Instructions are not original to the task. They are provided by Millisecond
as htm/html pages.
To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac)
or Notepad (Windows).

Summary Data

File Name: contextualcueingtask_summary*.iqdat

Data Fields

Raw Data

File Name: contextualcueingtask_raw*.iqdat

Data Fields

Parameters

The procedure can be adjusted by setting the following parameters.