Brain Lesion of the Right Hemisphere, Unilateral Spatial Neglect for Half of Them
Conditions
Keywords
Caloric Vestibular Stimulation Reward, Brain Stimulation, Reward, Vestibular System, Cingulate Cortex, Cancellation Tasks
Brief summary
The exploration of space is more effective when intrinsically rewarding elements are located in the visual scene. Thus, rewards could be exploited as a novel rehabilitation approach to various attentional disorders. The first part of the project aims to characterize these effects at the behavioural level. The interventional part consists then in the administration of Caloric Vestibular Stimulation (CVS), which by means of injection of a small quantity of water in the external ear activates the vestibular organs and subsequently vestibular-related brain areas. Among the observed brain activations, the possibility to reach cingulate areas appears particularly interesting because it foreshadows the possibility to further enhance attentional capture by rewards. CVS will be delivered to patients with brain lesion of the right hemisphere, engaged in cancellation tasks requiring the processing of targets of different nature (e.g. monetary or neutral). The main prediction is that CVS administration would enhance spatial exploration in terms of center of gravity of the cancellation and improved accuracy as a function of the type of target processed (e.g. its value).
Interventions
PROCEDURENon-invasive brain stimulation of the vestibular system through caloric vestibular stimulation.
Caloric vestibular stimulation (CVS) involves the irrigation of cold or warm water into the external ear canal, and induces a temperature gradient across the semicircular canals stimulating the vestibular nerve. It is commonly used in both otolaryngology to assess vestibular function and neurology to test brain stem function.
Sponsors
Hospices Civils de Lyon
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
* More than 18 years of age, less than 85 * right handed * Benefit of social health security * Normal or corrected-to-normal vision * Brain lesion localised in the right hemisphere, confirmed by CT or MRI
Exclusion criteria
* Anamnesis of neurological of psychiatric illness * Pregnancy or breastfeeding * Administrative measures restricting legal rights * Recent participation to other brain stimulation studies (\< 1 week) * Perforation of the tympanic membrane * Anamnesis of recurrent otitis media
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Center of Gravity (pixels). | Days 1, 2, and 3 | For line bisection defined as the difference between participants' mark and the objective center of the line. For cancellation tasks it is calculated as the grand average of horizontal and vertical coordinates of all the marks. In both cases smaller indices indicate a leftward exploration bias, whereas larger indices indicate rightward bias. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Reaction times (ms). | Days 1, 2, and 3. | The speed of response is a traditional indicator of the amount of cognitive processing underneath provided responses. It is measured by professional programs (e.g. Presentation) running on standard PCs |
| Response accuracy (%) | Days 1, 2, and 3. | The proportion of correct responses provided, automatically computed by professional programs (e.g. Presentation) running on standard PCs. |
Countries
France
Outcome results
None listed