Focus of Study: Higher Cognition and the Vestibular System
Conditions
Brief summary
Corroboratory behavioral evidence showed interaction effects between vestibular stimulation and egocentric transformation. The investigators here examine in healthy participants, whether there are shared brain mechanisms underlying galvanic vestibular stimulation, illusory self-motion and egocentric transformation, as well as their interaction. It is hypothesized that the GVS induced illusory self-motion dampens the ability to perform egocentric mental transformation.
Detailed description
Theories of embodied mental rotation suggest overlapping processes between real body and egocentric mental transformations. Corroboratory behavioral evidence showed interaction effects between vestibular stimulation and egocentric transformation. Yet, no study so far has investigated which cortical areas are involved in vestibular processing and/or illusory self-motion and mental transformation tasks within the same participants. This however seems crucial, as important individual differences exist for both mental transformation abilities as well as in subjective perception of artificial vestibular stimulation. The primary objective is to reveal which brain area(s) are involved in the interaction of illusory self-motion (as induced by galvanic vestibular stimulation (GVS)) and egocentric mental transformation, as compared to no illusory self-motion or object-based mental transformation. It is hypothesized that the GVS induced illusory self-motion dampens the ability to perform egocentric mental transformation more than object-based mental transformation. As previous behavioral studies on such an interaction were always done in a sitting position, a secondary objective is to first replicate previous behavioral mental rotation studies that used GVS, in the Magnetic Resonance (MR) -scanner comparable setting. Moreover, as no brain imaging study so far has investigated subjective illusory motion experience induced by GVS, illusory self-motion will be measured and included in the statistical model to find specific brain regions modulating the illusory self-motion perception.
Interventions
The investigators aim to study the influence of Galvanic Vestibular Stimulation on the brain mechanisms underlying illusory self-motion and its influence on egocentric mental transformation. As a control condition sham stimulation will be applied by the same device within the same participants in different trials. Participants should not note the difference.
Sponsors
University of Zurich
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
18 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
* Male * Written informed consent by the participant * Right handed
Exclusion criteria
* possession of metallic implants, cardiac pacemakers, neuro-stimulators, metal splinter injuries * claustrophobia * no ability to lie still in the scanner, e.g. a cold leading to frequent sneezing and subsequent head movements * history of neurological or psychiatric disorder * hearing problems * concomitant medication * strong motion sensitivity * vestibular deficits
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Blood Oxygen-Level Dependent (BOLD) -signal change in response to egocentric mental transformation | one day | The Relative BOLD-signal change in response to egocentric mental transformation during GVS versus mental transformation during sham stimulation will be measured in an functional Magnetic Resonance Imaging (fMRI) paradigm |
Outcome results
None listed