Attentional Blink Task

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

Created: January 04, 2013

Last Modified: January 26, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

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 et al (1992) and Folk et al (2002).

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)

References

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.

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.

Duration

30 minutes

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.

Procedure

- 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

Letter Presentation Time

Stimuli

Items can be edited under EDITABLE STIMULI;
Text sizes can be edited under EDITABLE PARAMETERS

Instructions

Instructions are provided by Millisecond
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.

Summary Data

File Name: simpleattentionalblink_summary*.iqdat

Data Fields

Raw Data

File Name: simpleattentionalblink_raw*.iqdat

Data Fields

Parameters

The procedure can be adjusted by setting the following parameters.