Imaging During Subliminal Perception

University of Zurich (UZH)

Status: Completed

Conditions: Healthy

Treatments: Other: real-time fMRI

Study type: Observational

Funder types: Other

Identifiers

NCT04643340

2017-00483

Details and patient eligibility

About

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.

Full description

In this project, using healthy adults, the investigators have 2 aims:

1. Apply electroencephalography (EEG) and fMRI before and after rt-fMRI neurofeedback during attention tasks to identify brain regions involved in subliminal and supraliminal perception.
2. Apply functional connectivity analyses during these tasks.

Enrollment: 70 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: Accepts Healthy Volunteers

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)

Trial design

70 participants in 3 patient groups

active group 1

Description:

This group will train the insular cortex by real-time fMRI

Treatment:

Other: real-time fMRI

active group 2

Description:

This group will train the visual cortex by real-time fMRI

Treatment:

Other: real-time fMRI

sham

Description:

This group will only train the insula by a particular strategy