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Activation in a frontoparietal cortical network underlies individual differences in the performance of an embedded figures task.

Walter E, Dassonville P - PLoS ONE (2011)

Bottom Line: In the present study, we found that similar parietal regions (superior parietal cortex and precuneus) were more active during the EFT than during a simple matching task.Additional parietal and frontal areas, in the right hemisphere, showed strong correlations between brain activity and behavioral performance during the search task.We propose that the posterior parietal regions are necessary for processing contextual information across many different, but related visuospatial tasks, with additional parietal and frontal regions serving to coordinate this processing in participants proficient in the task.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America.

ABSTRACT
The Embedded Figures Test (EFT) requires observers to search for a simple geometric shape hidden inside a more complex figure. Surprisingly, performance in the EFT is negatively correlated with susceptibility to illusions of spatial orientation, such as the Roelofs effect. Using fMRI, we previously demonstrated that regions in parietal cortex are involved in the contextual processing associated with the Roelofs task. In the present study, we found that similar parietal regions (superior parietal cortex and precuneus) were more active during the EFT than during a simple matching task. Importantly, these parietal activations overlapped with regions found to be involved during contextual processing in the Roelofs illusion. Additional parietal and frontal areas, in the right hemisphere, showed strong correlations between brain activity and behavioral performance during the search task. We propose that the posterior parietal regions are necessary for processing contextual information across many different, but related visuospatial tasks, with additional parietal and frontal regions serving to coordinate this processing in participants proficient in the task.

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A comparison of the brain activation for performance of the EFT, the Roelofs task, and an eye movement localizer task.(a) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed an eye movement localizer task, in addition to the EFT (n = 9). Yellow voxels depict those areas significantly more active during the search trials than during the matching trials; blue, regions activated during the eye movement localizer task; and green, regions common to both the search >> masking contrast as well to as the eye movement localizer task. (b) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed the Roelofs task (Walter and Dassonville, 2008), in addition to the eye movement localizer and EFT. Red voxels depict those areas significantly activated during both the Roelofs task as well as the EFT; blue, regions activated during the eye movement localizer task; and purple, regions common to all three tasks. All contrasts are thresholded at p<0.05, Bonferroni corrected.
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pone-0020742-g005: A comparison of the brain activation for performance of the EFT, the Roelofs task, and an eye movement localizer task.(a) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed an eye movement localizer task, in addition to the EFT (n = 9). Yellow voxels depict those areas significantly more active during the search trials than during the matching trials; blue, regions activated during the eye movement localizer task; and green, regions common to both the search >> masking contrast as well to as the eye movement localizer task. (b) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed the Roelofs task (Walter and Dassonville, 2008), in addition to the eye movement localizer and EFT. Red voxels depict those areas significantly activated during both the Roelofs task as well as the EFT; blue, regions activated during the eye movement localizer task; and purple, regions common to all three tasks. All contrasts are thresholded at p<0.05, Bonferroni corrected.

Mentions: To account for possible differential effects of eye movements in the search and matching tasks, we compared our EFT results to those from an additional eye movement localizer task completed by nine of our participants. Because the intent of this analysis was to compare activations within the tested group of participants, we performed a fixed-effects analysis of the eye-movement activations and compared the results with those of a fixed-effects analysis of the EFT data (voxel-wise threshold of p<0.05, Bonferroni corrected). During the eye movement localizer blocks, extensive regions of cortex were significantly activated, including the frontal eye fields (FEF; precentral gyrus) and regions in the parietal cortex, with foci near the intraparietal sulcus. In addition, large regions of the occipital (BA 17/18) and inferior parietal cortices (BA 40) were activated during the eye movement localizer. Although the frontal areas active in the EFT (search >> matching) contrast did overlap with areas implicated in the eye movement localizer task, the profile of parietal activations associated with the EFT was very different from that associated with the eye movement localizer task (see Figure 5a). Indeed, of the parietal cortex activated in the EFT, 76.2% showed no overlap with the areas activated in the eye movement localizer task. In addition, the parietal saccade-related activations did not overlap with the parietal regions whose activations were correlated with individual differences in the rate of processing in the EFT.


Activation in a frontoparietal cortical network underlies individual differences in the performance of an embedded figures task.

Walter E, Dassonville P - PLoS ONE (2011)

A comparison of the brain activation for performance of the EFT, the Roelofs task, and an eye movement localizer task.(a) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed an eye movement localizer task, in addition to the EFT (n = 9). Yellow voxels depict those areas significantly more active during the search trials than during the matching trials; blue, regions activated during the eye movement localizer task; and green, regions common to both the search >> masking contrast as well to as the eye movement localizer task. (b) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed the Roelofs task (Walter and Dassonville, 2008), in addition to the eye movement localizer and EFT. Red voxels depict those areas significantly activated during both the Roelofs task as well as the EFT; blue, regions activated during the eye movement localizer task; and purple, regions common to all three tasks. All contrasts are thresholded at p<0.05, Bonferroni corrected.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3140479&req=5

pone-0020742-g005: A comparison of the brain activation for performance of the EFT, the Roelofs task, and an eye movement localizer task.(a) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed an eye movement localizer task, in addition to the EFT (n = 9). Yellow voxels depict those areas significantly more active during the search trials than during the matching trials; blue, regions activated during the eye movement localizer task; and green, regions common to both the search >> masking contrast as well to as the eye movement localizer task. (b) Brain regions showing voxels significantly activated in a fixed-effects analysis of all participants who performed the Roelofs task (Walter and Dassonville, 2008), in addition to the eye movement localizer and EFT. Red voxels depict those areas significantly activated during both the Roelofs task as well as the EFT; blue, regions activated during the eye movement localizer task; and purple, regions common to all three tasks. All contrasts are thresholded at p<0.05, Bonferroni corrected.
Mentions: To account for possible differential effects of eye movements in the search and matching tasks, we compared our EFT results to those from an additional eye movement localizer task completed by nine of our participants. Because the intent of this analysis was to compare activations within the tested group of participants, we performed a fixed-effects analysis of the eye-movement activations and compared the results with those of a fixed-effects analysis of the EFT data (voxel-wise threshold of p<0.05, Bonferroni corrected). During the eye movement localizer blocks, extensive regions of cortex were significantly activated, including the frontal eye fields (FEF; precentral gyrus) and regions in the parietal cortex, with foci near the intraparietal sulcus. In addition, large regions of the occipital (BA 17/18) and inferior parietal cortices (BA 40) were activated during the eye movement localizer. Although the frontal areas active in the EFT (search >> matching) contrast did overlap with areas implicated in the eye movement localizer task, the profile of parietal activations associated with the EFT was very different from that associated with the eye movement localizer task (see Figure 5a). Indeed, of the parietal cortex activated in the EFT, 76.2% showed no overlap with the areas activated in the eye movement localizer task. In addition, the parietal saccade-related activations did not overlap with the parietal regions whose activations were correlated with individual differences in the rate of processing in the EFT.

Bottom Line: In the present study, we found that similar parietal regions (superior parietal cortex and precuneus) were more active during the EFT than during a simple matching task.Additional parietal and frontal areas, in the right hemisphere, showed strong correlations between brain activity and behavioral performance during the search task.We propose that the posterior parietal regions are necessary for processing contextual information across many different, but related visuospatial tasks, with additional parietal and frontal regions serving to coordinate this processing in participants proficient in the task.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America.

ABSTRACT
The Embedded Figures Test (EFT) requires observers to search for a simple geometric shape hidden inside a more complex figure. Surprisingly, performance in the EFT is negatively correlated with susceptibility to illusions of spatial orientation, such as the Roelofs effect. Using fMRI, we previously demonstrated that regions in parietal cortex are involved in the contextual processing associated with the Roelofs task. In the present study, we found that similar parietal regions (superior parietal cortex and precuneus) were more active during the EFT than during a simple matching task. Importantly, these parietal activations overlapped with regions found to be involved during contextual processing in the Roelofs illusion. Additional parietal and frontal areas, in the right hemisphere, showed strong correlations between brain activity and behavioral performance during the search task. We propose that the posterior parietal regions are necessary for processing contextual information across many different, but related visuospatial tasks, with additional parietal and frontal regions serving to coordinate this processing in participants proficient in the task.

Show MeSH
Related in: MedlinePlus