NCT06140940

Motor Imagery in Aphantasia

Probing and Modulating Motor Imagery Capacities in Aphantasia

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 40 (estimated)
• Sponsor: Hôpital le Vinatier · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

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.

Conditions

• Aphasia

Interventions

Type	Name	Description
PROCEDURE	High-definition transcranial direct current (HD-tDCS), active condition	Participants will receive a session of active HD-tDCS at a current intensity of 4 mA for a duration of 15min. The placement of electrodes will be determined to specifically target the primary motor cortex (4 x 1 montage with the anode over C4). During the stimulation, participants will be engaged in a mental training task (sequential finger tapping-task).
PROCEDURE	High-definition transcranial direct current (HD-tDCS), sham condition	Participants will receive a session of sham HD-tDCS, which will be delivered following the same procedures as active HD-tDCS but the intensity of the current will be set at 4mA during the 30 first seconds at the beginning of the 15-min period of the stimulation, and equal to 0 mA for the reminding period of stimulation to simulate the tingling sensation often experienced by individuals during active stimulation. The placement of electrodes will be determined to specifically target the primary motor cortex (4 x 1 montage with the anode over C4). During the stimulation, participants will be engaged in a mental training task (sequential finger tapping-task).

Timeline

• Start date: 2024-03-28
• Primary completion: 2027-01-01
• Completion: 2028-01-01
• First posted: 2023-11-21
• Last updated: 2025-07-24

Locations

1 site across 1 country: France