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Disruption of Foveal Space Impairs Discrimination of Peripheral Objects.

Weldon KB, Rich AN, Woolgar A, Williams MA - Front Psychol (2016)

Bottom Line: Despite this well-known fact, neuroimaging studies have found information about peripheral objects in the foveal confluence, the cortical region representing the fovea.This was specific to a central distractor; a peripheral distractor at the same time point did not have the same effect.These results are consistent with the claim that foveal retinotopic cortex is recruited for extra-foveal perception.

View Article: PubMed Central - PubMed

Affiliation: Perception in Action Research Centre, Department of Cognitive Science, Faculty of Human Sciences, Macquarie UniversitySydney, NSW, Australia; ARC Centre of Excellence in Cognition and its Disorders, Macquarie UniversitySydney, NSW, Australia.

ABSTRACT
Visual space is retinotopically mapped such that peripheral objects are processed in a cortical region outside the region that represents central vision. Despite this well-known fact, neuroimaging studies have found information about peripheral objects in the foveal confluence, the cortical region representing the fovea. Further, this information is behaviorally relevant: disrupting the foveal confluence using transcranial magnetic stimulation impairs discrimination of peripheral objects at time-points consistent with a disruption of feedback. If the foveal confluence receives feedback of information about peripheral objects to boost vision, there should be behavioral consequences of this phenomenon. Here, we tested the effect of foveal distractors at different stimulus onset asynchronies (SOAs) on discrimination of peripheral targets. Participants performed a discrimination task on target objects presented in the periphery while fixating centrally. A visual distractor presented at the fovea ~100 ms after presentation of the targets disrupted performance more than a central distractor presented at other SOAs. This was specific to a central distractor; a peripheral distractor at the same time point did not have the same effect. These results are consistent with the claim that foveal retinotopic cortex is recruited for extra-foveal perception. This study describes a new paradigm for investigating the nature of the foveal feedback phenomenon and demonstrates the importance of this feedback in peripheral vision.

No MeSH data available.


Schematic of three peripheral distractor trial types in Experiment 2. The targets and the distractor were always displayed for 117 ms regardless of SOA. The distractor appeared either (A) 267 ms or 117 ms prior to target onset, (B) simultaneously with target onset, or (C) 117 ms or 267 ms after target onset.
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Figure 4: Schematic of three peripheral distractor trial types in Experiment 2. The targets and the distractor were always displayed for 117 ms regardless of SOA. The distractor appeared either (A) 267 ms or 117 ms prior to target onset, (B) simultaneously with target onset, or (C) 117 ms or 267 ms after target onset.

Mentions: All aspects of the stimuli and apparatus were the same as Experiment 1, with the exception that there was no inconsistent distractor – all trials had the “consistent” smoothie distractor as the visual distractor – and the distractor appeared centrally on only half the trials. On the other half of the trials, the distractor appeared in the periphery at 6.5° eccentricity, but at a different location to the target stimuli (Figure 4). To ensure the participant knew which stimuli were the targets, the stimuli always appeared in the same configuration: targets in the upper left and lower right quadrants of the screen. When present, the peripheral distractor always appeared in the upper right quadrant of the screen.


Disruption of Foveal Space Impairs Discrimination of Peripheral Objects.

Weldon KB, Rich AN, Woolgar A, Williams MA - Front Psychol (2016)

Schematic of three peripheral distractor trial types in Experiment 2. The targets and the distractor were always displayed for 117 ms regardless of SOA. The distractor appeared either (A) 267 ms or 117 ms prior to target onset, (B) simultaneously with target onset, or (C) 117 ms or 267 ms after target onset.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4862972&req=5

Figure 4: Schematic of three peripheral distractor trial types in Experiment 2. The targets and the distractor were always displayed for 117 ms regardless of SOA. The distractor appeared either (A) 267 ms or 117 ms prior to target onset, (B) simultaneously with target onset, or (C) 117 ms or 267 ms after target onset.
Mentions: All aspects of the stimuli and apparatus were the same as Experiment 1, with the exception that there was no inconsistent distractor – all trials had the “consistent” smoothie distractor as the visual distractor – and the distractor appeared centrally on only half the trials. On the other half of the trials, the distractor appeared in the periphery at 6.5° eccentricity, but at a different location to the target stimuli (Figure 4). To ensure the participant knew which stimuli were the targets, the stimuli always appeared in the same configuration: targets in the upper left and lower right quadrants of the screen. When present, the peripheral distractor always appeared in the upper right quadrant of the screen.

Bottom Line: Despite this well-known fact, neuroimaging studies have found information about peripheral objects in the foveal confluence, the cortical region representing the fovea.This was specific to a central distractor; a peripheral distractor at the same time point did not have the same effect.These results are consistent with the claim that foveal retinotopic cortex is recruited for extra-foveal perception.

View Article: PubMed Central - PubMed

Affiliation: Perception in Action Research Centre, Department of Cognitive Science, Faculty of Human Sciences, Macquarie UniversitySydney, NSW, Australia; ARC Centre of Excellence in Cognition and its Disorders, Macquarie UniversitySydney, NSW, Australia.

ABSTRACT
Visual space is retinotopically mapped such that peripheral objects are processed in a cortical region outside the region that represents central vision. Despite this well-known fact, neuroimaging studies have found information about peripheral objects in the foveal confluence, the cortical region representing the fovea. Further, this information is behaviorally relevant: disrupting the foveal confluence using transcranial magnetic stimulation impairs discrimination of peripheral objects at time-points consistent with a disruption of feedback. If the foveal confluence receives feedback of information about peripheral objects to boost vision, there should be behavioral consequences of this phenomenon. Here, we tested the effect of foveal distractors at different stimulus onset asynchronies (SOAs) on discrimination of peripheral targets. Participants performed a discrimination task on target objects presented in the periphery while fixating centrally. A visual distractor presented at the fovea ~100 ms after presentation of the targets disrupted performance more than a central distractor presented at other SOAs. This was specific to a central distractor; a peripheral distractor at the same time point did not have the same effect. These results are consistent with the claim that foveal retinotopic cortex is recruited for extra-foveal perception. This study describes a new paradigm for investigating the nature of the foveal feedback phenomenon and demonstrates the importance of this feedback in peripheral vision.

No MeSH data available.