Clinical trial NCT06140940: Motor Imagery in Aphantasia
Official title: Probing and Modulating Motor Imagery Capacities in Aphantasia
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Aphasia
Lead sponsor: Hôpital le Vinatier
Sponsor class: OTHER
First posted: 2023-11-21
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Single-center prospective randomized, double-blind, sham-controlled, crossover study with two conditions: active tDCS + mental training and sham tDCS + mental training. A control group (participants with typical mental imagery abilities) will also be included for comparison at baseline.
Primary purpose: BASIC_SCIENCE

Brief summary: The present study aims to characterize and modulate motor imagery abilities in individuals with aphantasia. The investigators will characterize the neurophysiological and physiological underpinnings of mental imagery abilities in participants with aphantasia by investigating several indices of motor imagery abilities and comparing them to participants with typical mental imagery abilities. The investigators will investigate whether non-invasive brain stimulation applied to the primary motor cortex improves mental imagery abilities in participants with aphantasia.

Detailed description: The investigators will recruit 20 participants with aphantasia and 20 participants with typical mental imagery capacities (no-aphantasia groups). Participants in both groups will complete a 3-hour visit for inclusion and baseline measurements (Visit 1) which will include neurophysiological, autonomic nervous system, cognitive and behavioral measures.

Participants in the aphantasia group will complete 2 additional visits to receive active and sham tDCS sessions (Visit 2 and 3), according to a randomized, double-blind, sham-controlled, crossover design. Mental training will be done concurrently with tDCS using a sequential finger tapping-task (Truong et al., 2022). Participants will receive the instructions of trying to imagine themselves performing the motor task, by feeling their fingers moving as if they were actually moving it (kinesthetic modality of motor imagery).

Visits will be separated by at least 7 days.

Eligibility criteria: Inclusion Criteria:

* For the aphantasia group only: congenital aphantasia defined as a life-long inability to generate mental imagery (confirmed by a total score of 32 or less on the VVIQ, which is the gold standard questionnaire for aphantasia)
* For the no-aphantasia group only: typical mental imagery capacities (confirmed by a total score of more than 32 on the VVIQ)
* Covered by public health insurance
* Understanding the French language
* Signed written informed consent after being informed about the study

Exclusion Criteria:

* Presence or history of a somatic, neurologic, or mental illness
* Actual pain or musculoskeletal disorders at the upper limb
* Having a regular musical activity (more than once a week) because of high manual dexterity
* Contraindication for noninvasive brain stimulation including the presence of ferromagnetic or magnetic sensitive metal objects implanted in the head or in close proximity (e.g., brain stent, clip, cochlear implants, or stimulator)
* Pregnancy (controlled by urine pregnancy test in females without reported contraception)
* Active seizure disorder or history of seizures
* Participants under curatorship/guardianship

Primary outcomes:
measure: Gains in motor performance following mental training
timeFrame: 2 times: immediately before tDCS (baseline) and immediately after tDCS
Secondary outcomes:
measure: Motor corticospinal excitability at rest and during kinesthetic motor imagery
timeFrame: 1 time at baseline (Visit 1), in both groups
measure: Heart rate variability
timeFrame: through study completion, an average of 1 month
measure: Skin conductance
timeFrame: through study completion, an average of 1 month
measure: Mental imagery abilities
timeFrame: 1 time at baseline, in both groups
measure: Mental imagery abilities
timeFrame: 1 time at baseline, in both groups
measure: Mental imagery abilities
timeFrame: 1 time at baseline, in both groups
measure: Mental imagery abilities
timeFrame: 1 time at baseline, in both groups
measure: Mental imagery abilities
timeFrame: 1 time at baseline, in both groups
measure: Source monitoring performance
timeFrame: 1 time at baseline, in both groups
measure: Implicit motor imagery capacities
timeFrame: 1 time at baseline, in both groups
measure: Performance of time-to-contact estimation
timeFrame: 1 time at baseline, in both groups
Other outcomes:
Locations:
city: Bron
country: France
facility: Centre Hospitalier le Vinatier
Study officials:
affiliation: CH le Vinatier
name: Marine MONDINO, PhD
role: PRINCIPAL_INVESTIGATOR
References: