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The roles of occipital and parietal regions in visual awareness: A Transcranial Magnetic Stimulation study

Recruiting
Conditions
niet van toepassing
nvt
Registration Number
NL-OMON33292
Lead Sponsor
Radboud Universiteit Nijmegen
Brief Summary

Not available

Detailed Description

Not available

Recruitment & Eligibility

Status
Recruiting
Sex
Not specified
Target Recruitment
60
Inclusion Criteria

Right-handed individuals, with normal or corrected-to-normal vision and no history of neurological or psychological disorders are included.

Exclusion Criteria

- Pacemaker
- Metal parts in head or mouth
- History of brain surgery
- History of epilepsy or first-grade family member with epilepsy
- Psychological or neurological disorder
- Pregnancy

Study & Design

Study Type
Interventional
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
<p>The effect of TMS on the three stimulation sites in the main experiment will be<br /><br>assessed using a visual task performed in an fMRI scanner. We will test whether<br /><br>stimulation to V1, PPC, and vertex differentially affected subjects* visibility<br /><br>ratings. We predict that V1 stimulation will lead to decrease in visibility<br /><br>ratings for gratings presented anywhere in the visual field, while PPC<br /><br>stimulation will only affect the visibility of gratings in the contralateral<br /><br>visual field. Vertex stimulation is not expected to have any effects on<br /><br>visibility ratings. Further, we predict that the changes in visibility rating<br /><br>will be mediated by changes in the activation patterns in the prefrontal cortex<br /><br>and will test for that in the fMRI part of the experiment.</p><br>
Secondary Outcome Measures
NameTimeMethod
<p>The effectiveness of TMS stimulation will be assessed in a pilot experiment. We<br /><br>will test whether stimulation to V1, PPC, and vertex differentially affected<br /><br>subjects* visibility ratings. Again, we predict that V1 stimulation will lead<br /><br>to decrease in visibility ratings for gratings presented anywhere in the visual<br /><br>field, while PPC stimulation will only affect the visibility of gratings in the<br /><br>contralateral visual field. Vertex stimulation is not expected to have any<br /><br>effects on visibility ratings. In the pilot experiment we will only collect<br /><br>behavioural data in order to assess the effectiveness of TMS.</p><br>
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