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Shared processing in multiple object tracking and visual working memory in the absence of response order and task order confounds

View Article: PubMed Central - PubMed

ABSTRACT

To understand how the visual system represents multiple moving objects and how those representations contribute to tracking, it is essential that we understand how the processes of attention and working memory interact. In the work described here we present an investigation of that interaction via a series of tracking and working memory dual-task experiments. Previously, it has been argued that tracking is resistant to disruption by a concurrent working memory task and that any apparent disruption is in fact due to observers making a response to the working memory task, rather than due to competition for shared resources. Contrary to this, in our experiments we find that when task order and response order confounds are avoided, all participants show a similar decrease in both tracking and working memory performance. However, if task and response order confounds are not adequately controlled for we find substantial individual differences, which could explain the previous conflicting reports on this topic. Our results provide clear evidence that tracking and working memory tasks share processing resources.

No MeSH data available.


Experiment 2: Mean accuracy in each condition.Single-task and dual-task performance for each observer for the multiple object tracking (MOT) and visual working memory (VWM) tasks. Group analysis to the far right. Error bars represent 95% confidence intervals.
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pone.0175736.g005: Experiment 2: Mean accuracy in each condition.Single-task and dual-task performance for each observer for the multiple object tracking (MOT) and visual working memory (VWM) tasks. Group analysis to the far right. Error bars represent 95% confidence intervals.

Mentions: Results are shown in Fig 5 in a format consistent with the previous two figures and numerically in Table 4. A response (MOT, VWM) by load (single, dual) ANOVA of all observers’ data revealed a main effect of load, F(1, 16) = 54.49, p < .001. There was no main effect of response and no interaction between load and response. Accuracy was greater under single-task conditions compared to dual-task conditions for MOT performance and VWM performance. Planned comparisons were analysed via logistic regression for each individual’s data, and t-tests for group data. Significance was tested against a Bonferroni adjusted alpha level of .004 (.05/12). For the majority of observers, performance was qualitatively identical to the group data (See Table 4); however, the difference between single- and dual-task MOT performance did not reach the conservative Bonferroni adjusted alpha-level for observers M.L. and S.S, and was marginally significant for observer R.Y. A significant interaction was found for observer S.S., β = 0.67, t(1020) = 2.30, p = .02; under single task conditions VWM performance was greater than MOT performance, β = .57, t(1020) = 2.52, p = .01, however under dual task conditions there was no difference, p = .58.


Shared processing in multiple object tracking and visual working memory in the absence of response order and task order confounds
Experiment 2: Mean accuracy in each condition.Single-task and dual-task performance for each observer for the multiple object tracking (MOT) and visual working memory (VWM) tasks. Group analysis to the far right. Error bars represent 95% confidence intervals.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5391939&req=5

pone.0175736.g005: Experiment 2: Mean accuracy in each condition.Single-task and dual-task performance for each observer for the multiple object tracking (MOT) and visual working memory (VWM) tasks. Group analysis to the far right. Error bars represent 95% confidence intervals.
Mentions: Results are shown in Fig 5 in a format consistent with the previous two figures and numerically in Table 4. A response (MOT, VWM) by load (single, dual) ANOVA of all observers’ data revealed a main effect of load, F(1, 16) = 54.49, p < .001. There was no main effect of response and no interaction between load and response. Accuracy was greater under single-task conditions compared to dual-task conditions for MOT performance and VWM performance. Planned comparisons were analysed via logistic regression for each individual’s data, and t-tests for group data. Significance was tested against a Bonferroni adjusted alpha level of .004 (.05/12). For the majority of observers, performance was qualitatively identical to the group data (See Table 4); however, the difference between single- and dual-task MOT performance did not reach the conservative Bonferroni adjusted alpha-level for observers M.L. and S.S, and was marginally significant for observer R.Y. A significant interaction was found for observer S.S., β = 0.67, t(1020) = 2.30, p = .02; under single task conditions VWM performance was greater than MOT performance, β = .57, t(1020) = 2.52, p = .01, however under dual task conditions there was no difference, p = .58.

View Article: PubMed Central - PubMed

ABSTRACT

To understand how the visual system represents multiple moving objects and how those representations contribute to tracking, it is essential that we understand how the processes of attention and working memory interact. In the work described here we present an investigation of that interaction via a series of tracking and working memory dual-task experiments. Previously, it has been argued that tracking is resistant to disruption by a concurrent working memory task and that any apparent disruption is in fact due to observers making a response to the working memory task, rather than due to competition for shared resources. Contrary to this, in our experiments we find that when task order and response order confounds are avoided, all participants show a similar decrease in both tracking and working memory performance. However, if task and response order confounds are not adequately controlled for we find substantial individual differences, which could explain the previous conflicting reports on this topic. Our results provide clear evidence that tracking and working memory tasks share processing resources.

No MeSH data available.