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Evidence for attentional processing in spatial localization.

Adam JJ, Davelaar EJ, van der Gouw A, Willems P - Psychol Res (2007)

Bottom Line: Using a dual-task methodology, this study examined the involvement of selective attention in spatial localization.Results revealed a robust interference effect in localization performance at short target durations that depended on the number of the to-be-identified distractor items.This outcome provides convergent support for the role of the attentional system in spatial localization.

View Article: PubMed Central - PubMed

Affiliation: Department of Movement Sciences, University of Maastricht, P.O. Box 616, 6200 MD, Maastricht, The Netherlands. jos.adam@bw.unimaas.nl

ABSTRACT
Using a dual-task methodology, this study examined the involvement of selective attention in spatial localization. Thirty participants located a single, briefly presented, peripheral target stimulus, appearing in one of 50 positions on either side of a central fixation point, with or without the requirement to identify a simultaneously presented central distractor stimulus. Results revealed a robust interference effect in localization performance at short target durations that depended on the number of the to-be-identified distractor items. This outcome provides convergent support for the role of the attentional system in spatial localization.

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Schematic representation of the visual stimuli (upper part) and trial sequence (lower part) in the single- and dual-task conditions. Note that the key difference between single- and dual-task conditions is the appearance of the central distractor stimulus in the dual-task condition, containing 1, 2, or 3 to-be-identified digits (for the 1-, 2-, and 3-distractor groups, respectively). In the single-task condition there is no distractor stimulus; here the neutral fixation sign (+) continues to be visible for the same duration as the distractor stimulus (i.e., 29 ms)
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Fig1: Schematic representation of the visual stimuli (upper part) and trial sequence (lower part) in the single- and dual-task conditions. Note that the key difference between single- and dual-task conditions is the appearance of the central distractor stimulus in the dual-task condition, containing 1, 2, or 3 to-be-identified digits (for the 1-, 2-, and 3-distractor groups, respectively). In the single-task condition there is no distractor stimulus; here the neutral fixation sign (+) continues to be visible for the same duration as the distractor stimulus (i.e., 29 ms)

Mentions: At the beginning of each trial in the single task condition (localization only), a fixation sign (‘+’) appeared in the center of the screen (Fig. 1). After 1,000 ms the target stimulus (‘*’) was presented at one of 50 possible stimulus locations on an imaginary horizontal row on either side of the fixation sign (25 stimulus locations to the left and 25 to the right). After a variable delay (target-mask onset delay) a masking stimulus was presented to control the visibility of the target stimulus. The masking stimulus consisted of two horizontal strings of each 29 ‘*’ signs covering all possible target locations on the left and right of fixation (plus four extra, non-target positions). The masking stimulus remained present throughout the remainder of the trial. Eight target-mask onset asynchronies or target durations were employed: 29, 57, 86, 114, 143, 200, 300, and 400 ms. The participants’ task was to indicate the location of the target stimulus as accurately as possible by moving the cursor (a rectangle) from the fixation sign to the observed position of the target stimulus. Movement of the cursor was realized by manipulating the cursor keys on the keyboard with the index and ring fingers of the right hand. When subjects reached the perceived target location they confirmed their response by pressing the space bar with their left hand. No feedback was provided. An intertrial interval of 1.5 s separated the final response in one trial from the start of the next trial. Participants were instructed to fixate their eyes on the fixation sign at the beginning of each trial, but were told that they were free to make eye movements toward the target.Fig. 1


Evidence for attentional processing in spatial localization.

Adam JJ, Davelaar EJ, van der Gouw A, Willems P - Psychol Res (2007)

Schematic representation of the visual stimuli (upper part) and trial sequence (lower part) in the single- and dual-task conditions. Note that the key difference between single- and dual-task conditions is the appearance of the central distractor stimulus in the dual-task condition, containing 1, 2, or 3 to-be-identified digits (for the 1-, 2-, and 3-distractor groups, respectively). In the single-task condition there is no distractor stimulus; here the neutral fixation sign (+) continues to be visible for the same duration as the distractor stimulus (i.e., 29 ms)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2367386&req=5

Fig1: Schematic representation of the visual stimuli (upper part) and trial sequence (lower part) in the single- and dual-task conditions. Note that the key difference between single- and dual-task conditions is the appearance of the central distractor stimulus in the dual-task condition, containing 1, 2, or 3 to-be-identified digits (for the 1-, 2-, and 3-distractor groups, respectively). In the single-task condition there is no distractor stimulus; here the neutral fixation sign (+) continues to be visible for the same duration as the distractor stimulus (i.e., 29 ms)
Mentions: At the beginning of each trial in the single task condition (localization only), a fixation sign (‘+’) appeared in the center of the screen (Fig. 1). After 1,000 ms the target stimulus (‘*’) was presented at one of 50 possible stimulus locations on an imaginary horizontal row on either side of the fixation sign (25 stimulus locations to the left and 25 to the right). After a variable delay (target-mask onset delay) a masking stimulus was presented to control the visibility of the target stimulus. The masking stimulus consisted of two horizontal strings of each 29 ‘*’ signs covering all possible target locations on the left and right of fixation (plus four extra, non-target positions). The masking stimulus remained present throughout the remainder of the trial. Eight target-mask onset asynchronies or target durations were employed: 29, 57, 86, 114, 143, 200, 300, and 400 ms. The participants’ task was to indicate the location of the target stimulus as accurately as possible by moving the cursor (a rectangle) from the fixation sign to the observed position of the target stimulus. Movement of the cursor was realized by manipulating the cursor keys on the keyboard with the index and ring fingers of the right hand. When subjects reached the perceived target location they confirmed their response by pressing the space bar with their left hand. No feedback was provided. An intertrial interval of 1.5 s separated the final response in one trial from the start of the next trial. Participants were instructed to fixate their eyes on the fixation sign at the beginning of each trial, but were told that they were free to make eye movements toward the target.Fig. 1

Bottom Line: Using a dual-task methodology, this study examined the involvement of selective attention in spatial localization.Results revealed a robust interference effect in localization performance at short target durations that depended on the number of the to-be-identified distractor items.This outcome provides convergent support for the role of the attentional system in spatial localization.

View Article: PubMed Central - PubMed

Affiliation: Department of Movement Sciences, University of Maastricht, P.O. Box 616, 6200 MD, Maastricht, The Netherlands. jos.adam@bw.unimaas.nl

ABSTRACT
Using a dual-task methodology, this study examined the involvement of selective attention in spatial localization. Thirty participants located a single, briefly presented, peripheral target stimulus, appearing in one of 50 positions on either side of a central fixation point, with or without the requirement to identify a simultaneously presented central distractor stimulus. Results revealed a robust interference effect in localization performance at short target durations that depended on the number of the to-be-identified distractor items. This outcome provides convergent support for the role of the attentional system in spatial localization.

Show MeSH