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Brief report: eye movements during visual search tasks indicate enhanced stimulus discriminability in subjects with PDD.

Kemner C, van Ewijk L, van Engeland H, Hooge I - J Autism Dev Disord (2007)

Bottom Line: However, an alternative explanation is that subjects with PDD show a different, more effective search strategy.No evidence was found for a different search strategy between the groups.The data indicate an enhanced ability to discriminate between stimulus elements in PDD.

View Article: PubMed Central - PubMed

Affiliation: Department of Child and Adolescent Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. C.Kemner@umcutrecht.nl

ABSTRACT
Subjects with PDD excel on certain visuo-spatial tasks, amongst which visual search tasks, and this has been attributed to enhanced perceptual discrimination. However, an alternative explanation is that subjects with PDD show a different, more effective search strategy. The present study aimed to test both hypotheses, by measuring eye movements during visual search tasks in high functioning adult men with PDD and a control group. Subjects with PDD were significantly faster than controls in these tasks, replicating earlier findings in children. Eye movement data showed that subjects with PDD made fewer eye movements than controls. No evidence was found for a different search strategy between the groups. The data indicate an enhanced ability to discriminate between stimulus elements in PDD.

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Means and standard errors of the number of fixations for each group in trials with (left panel) and without a target (right panel), for the easy and hard condition
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Fig2: Means and standard errors of the number of fixations for each group in trials with (left panel) and without a target (right panel), for the easy and hard condition

Mentions: The analysis of number of fixations revealed a significant effect of group (F(1,11) = 10.3, p < .01). The individuals with PDD made significantly less fixations than the control group (means, respectively, 1.3 and 2.1). In addition, there were significant interactions between Group × Probe, Group × Display and Group × Probe × Display. When tested per level of Display, subjects with PDD showed significantly fewer fixations for all display sizes (F(1,11) = 8.2, p = .015/9.4, p = .011/10.8, p = .007), but the effects were largest for the 25 set size. Interactions of Group × Probe effects were marginally significant for all set sizes (F(1,11) = 4.7, p = .052/4.0, p = .072/4.4, p = .06), indicating that group differences in number of fixations were largest in the target absent condition (see Fig. 2).Fig. 2


Brief report: eye movements during visual search tasks indicate enhanced stimulus discriminability in subjects with PDD.

Kemner C, van Ewijk L, van Engeland H, Hooge I - J Autism Dev Disord (2007)

Means and standard errors of the number of fixations for each group in trials with (left panel) and without a target (right panel), for the easy and hard condition
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2254472&req=5

Fig2: Means and standard errors of the number of fixations for each group in trials with (left panel) and without a target (right panel), for the easy and hard condition
Mentions: The analysis of number of fixations revealed a significant effect of group (F(1,11) = 10.3, p < .01). The individuals with PDD made significantly less fixations than the control group (means, respectively, 1.3 and 2.1). In addition, there were significant interactions between Group × Probe, Group × Display and Group × Probe × Display. When tested per level of Display, subjects with PDD showed significantly fewer fixations for all display sizes (F(1,11) = 8.2, p = .015/9.4, p = .011/10.8, p = .007), but the effects were largest for the 25 set size. Interactions of Group × Probe effects were marginally significant for all set sizes (F(1,11) = 4.7, p = .052/4.0, p = .072/4.4, p = .06), indicating that group differences in number of fixations were largest in the target absent condition (see Fig. 2).Fig. 2

Bottom Line: However, an alternative explanation is that subjects with PDD show a different, more effective search strategy.No evidence was found for a different search strategy between the groups.The data indicate an enhanced ability to discriminate between stimulus elements in PDD.

View Article: PubMed Central - PubMed

Affiliation: Department of Child and Adolescent Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. C.Kemner@umcutrecht.nl

ABSTRACT
Subjects with PDD excel on certain visuo-spatial tasks, amongst which visual search tasks, and this has been attributed to enhanced perceptual discrimination. However, an alternative explanation is that subjects with PDD show a different, more effective search strategy. The present study aimed to test both hypotheses, by measuring eye movements during visual search tasks in high functioning adult men with PDD and a control group. Subjects with PDD were significantly faster than controls in these tasks, replicating earlier findings in children. Eye movement data showed that subjects with PDD made fewer eye movements than controls. No evidence was found for a different search strategy between the groups. The data indicate an enhanced ability to discriminate between stimulus elements in PDD.

Show MeSH