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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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The left panels show mean localization error as a function of target-mask onset delay in single- and dual-task conditions for the 1-, 2-, and 3-distractor groups (a, c, and e, respectively). The right panels show the results of the fitting procedure for the 1-, 2-, and 3-distractor groups (b, d, and f, respectively)
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Fig3: The left panels show mean localization error as a function of target-mask onset delay in single- and dual-task conditions for the 1-, 2-, and 3-distractor groups (a, c, and e, respectively). The right panels show the results of the fitting procedure for the 1-, 2-, and 3-distractor groups (b, d, and f, respectively)

Mentions: In the dual-task condition, where the localization task had to be performed together with the identification task, the performance function showed an initial decrease in error, reaching a stable level of performance after which it decreased further (see Fig. 3). Figure 3a shows mean localization error in single- and dual-task conditions for the 1-distractor group (averaged over target distance). As can be seen in Fig. 3a, localization error was substantially greater in the dual-task (1-distractor) condition than in the single-task (no-distractor) condition (F(1, 8) = 14.59, p < 0.001). This finding shows that the requirement to first identify the central distractor stimulus hampered localization performance and suggests that localization performance depends on the availability of selective visual attention. Importantly, this effect was qualified by a significant interaction with the factor target-mask onset delay (F(7, 56) = 7.46, p < 0.01). This interaction indicated that at the shortest target duration of 29 ms there was a robust (p < 0.001) interference effect that disappeared with the longer stimulus durations of 57 and 86 ms. This important outcome suggests that at the shortest target duration of 29 ms attention was not sufficiently available for localizing the target, as it was allocated to the task of identifying the distractor stimulus. Presumably, this raised localization error at the unattended target location. With the longer target durations of 57 and 86 ms, however, the interference effect disappeared, suggesting that attentional identification of the distractor stimulus had been completed and that visual attention had become increasingly available for, and shifted to, the peripheral target stimulus. Note that this early interference effect and its fast disappearance can not be attributed to the execution of eye movements because these effects occurred within 60 ms of presentation time, a time range far too short to execute saccades.Fig. 3


Evidence for attentional processing in spatial localization.

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

The left panels show mean localization error as a function of target-mask onset delay in single- and dual-task conditions for the 1-, 2-, and 3-distractor groups (a, c, and e, respectively). The right panels show the results of the fitting procedure for the 1-, 2-, and 3-distractor groups (b, d, and f, respectively)
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2367386&req=5

Fig3: The left panels show mean localization error as a function of target-mask onset delay in single- and dual-task conditions for the 1-, 2-, and 3-distractor groups (a, c, and e, respectively). The right panels show the results of the fitting procedure for the 1-, 2-, and 3-distractor groups (b, d, and f, respectively)
Mentions: In the dual-task condition, where the localization task had to be performed together with the identification task, the performance function showed an initial decrease in error, reaching a stable level of performance after which it decreased further (see Fig. 3). Figure 3a shows mean localization error in single- and dual-task conditions for the 1-distractor group (averaged over target distance). As can be seen in Fig. 3a, localization error was substantially greater in the dual-task (1-distractor) condition than in the single-task (no-distractor) condition (F(1, 8) = 14.59, p < 0.001). This finding shows that the requirement to first identify the central distractor stimulus hampered localization performance and suggests that localization performance depends on the availability of selective visual attention. Importantly, this effect was qualified by a significant interaction with the factor target-mask onset delay (F(7, 56) = 7.46, p < 0.01). This interaction indicated that at the shortest target duration of 29 ms there was a robust (p < 0.001) interference effect that disappeared with the longer stimulus durations of 57 and 86 ms. This important outcome suggests that at the shortest target duration of 29 ms attention was not sufficiently available for localizing the target, as it was allocated to the task of identifying the distractor stimulus. Presumably, this raised localization error at the unattended target location. With the longer target durations of 57 and 86 ms, however, the interference effect disappeared, suggesting that attentional identification of the distractor stimulus had been completed and that visual attention had become increasingly available for, and shifted to, the peripheral target stimulus. Note that this early interference effect and its fast disappearance can not be attributed to the execution of eye movements because these effects occurred within 60 ms of presentation time, a time range far too short to execute saccades.Fig. 3

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