Imaging During Subliminal Perception

Study Overview
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Brief Summary
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Subliminal perception of visual stimuli can be studied with functional brain imaging, e.g. with functional magnetic resonance imaging (fMRI). However, it is unclear how subliminal perception affects connectivity in the brain. Further, it is not known if real-time (rt) fMRI neurofeedback of brain areas involved in subliminal perception can lead to supra-threshold perception. For attention tasks, the investigators hypothesize that functional connectivity strength is mediated by the insular cortex during both supra-threshold and subliminal perception. Additionally, the investigators hypothesize that rt-fMRI neurofeedback training should alter neuronal and behavioral responses.

Detailed Description
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In this project, using healthy adults, the investigators have 2 aims: Apply electroencephalography (EEG) and fMRI before and after rt-fMRI neurofeedback during attention tasks to identify brain regions involved in subliminal and supraliminal perception. Apply functional connectivity analyses during these tasks.

Official Title
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Functional Imaging During Subliminal Perception

Conditions
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Healthy

Intervention / Treatment
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* Other: real-time fMRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy adults (> 18 < 80 years), which can read and sign the informed consent form Male and female Right-handed Exclusion Criteria: metallic items in the body (i.e. eye splinter, MR incompatible implants) pacemaker claustrophobia pregnant participants participants suffering from a degenerative disorder of the Central Nervous System, such as Stroke, Multiple Sclerosis, Parkinson's Disease, Alzheimer's Disease and Huntington's Disease and with major psychiatric disorders such as schizophrenia, depression, or anxiety disorder Drug intake (psychopharmaca)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| active group 1<br>This group will train the insular cortex by real-time fMRI | Other: real-time fMRI<br>* Brain regions can be trained, i.e. fMRI activity can be actively modulated online by humans, using rt-fMRI (Bruhl, Scherpiet et al. 2014, Bruhl 2015, Emmert, Kopel et al. 2016).<br>|
| active group 2<br>This group will train the visual cortex by real-time fMRI | Other: real-time fMRI<br>* Brain regions can be trained, i.e. fMRI activity can be actively modulated online by humans, using rt-fMRI (Bruhl, Scherpiet et al. 2014, Bruhl 2015, Emmert, Kopel et al. 2016).<br>|
| sham<br>This group will only train the insula by a particular strategy | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| fMRI during supra-threshold and subliminal perception |  | 2020 - 2022 | 
| rt-fMRI activity | rt-fMRI activity: fMRI signal changes during repetitive real time fMRI based training | 2020 - 2022 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional connectivity | Examination of fMRI signal dependencies (coherence) between brain regions. | 2020 - 2022 | 
| EEG activity | EEG activity: Event related potentials and spectral band power for different trial types | 2020 - 2022 | 
| fMRI task performance | Reaction time and accuracy | 2020 - 2022 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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functional MRI, subliminal perception, EEG, neurofeedback, attention