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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 an example trial in the basic discrimination training task. Targets were presented for decreasing durations (Δ, 417 ms, 267 ms, then 117 ms) during training until the participant was able to perform at 70% accuracy with a 117 ms presentation time.
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Figure 1: Schematic of an example trial in the basic discrimination training task. Targets were presented for decreasing durations (Δ, 417 ms, 267 ms, then 117 ms) during training until the participant was able to perform at 70% accuracy with a 117 ms presentation time.

Mentions: Prior to the experiment, participants were trained on a basic discrimination task. Two smoothies were displayed for 417 ms in the upper left and lower right quadrants of the screen (Figure 1). In half of the trials, these target stimuli were different smoothies randomly selected from the set of 16 exemplars, and in the other half they were identical smoothies. Participants fixated centrally and responded with their right index finger to indicate a “same” judgment or their right middle finger to indicate a “different” judgment. Following each response, participants were given onscreen accuracy feedback. The interstimulus interval was 2000 ms.


Disruption of Foveal Space Impairs Discrimination of Peripheral Objects.

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

Schematic of an example trial in the basic discrimination training task. Targets were presented for decreasing durations (Δ, 417 ms, 267 ms, then 117 ms) during training until the participant was able to perform at 70% accuracy with a 117 ms presentation time.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 1: Schematic of an example trial in the basic discrimination training task. Targets were presented for decreasing durations (Δ, 417 ms, 267 ms, then 117 ms) during training until the participant was able to perform at 70% accuracy with a 117 ms presentation time.
Mentions: Prior to the experiment, participants were trained on a basic discrimination task. Two smoothies were displayed for 417 ms in the upper left and lower right quadrants of the screen (Figure 1). In half of the trials, these target stimuli were different smoothies randomly selected from the set of 16 exemplars, and in the other half they were identical smoothies. Participants fixated centrally and responded with their right index finger to indicate a “same” judgment or their right middle finger to indicate a “different” judgment. Following each response, participants were given onscreen accuracy feedback. The interstimulus interval was 2000 ms.

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.