title: Brain correlates to facial motor imagery and its somatotopy in the primary motor cortex.
abstract: Motor imagery (MI) has attracted increased interest for motor rehabilitation as many studies have shown that MI shares the same neural networks as motor execution (ME). Nevertheless, MI in terms of facial movement has not been studied extensively; thus, in the present study, we investigated shared neural networks between facial motor imagery (FMI) and facial motor execution (FME). In addition, FMI somatotopy within-face was investigated between the forehead and the mouth. Functional MRI was used to examine 34 healthy individuals with ME and MI paradigms for the forehead and the mouth. The general linear model and a paired t-test were performed to define the facial area in the primary motor cortex (M1) and this area has been used to investigate somatotopy between the forehead and mouth FMI. FMI recruited similar brain motor areas as FME, but showed less neural activity in all activated regions. The facial areas in M1 were distinguishable from other body movements such as finger movement. Further investigation of this area showed that forehead and mouth imagery tended to lack a somatotopic representation for position on M1, and yet had distinct characteristics in terms of neural activity level. FMI showed different characteristics from general MI as the former exclusively activated facial processing areas. In addition, FME and FMI showed different characteristics in terms of BOLD signal level, while sharing the same neural areas. The results imply a potential usefulness of MI training for rehabilitation of facial motor disease considering that forehead and mouth somatotopy showed no clear position difference, and yet showed a significant BOLD signal intensity variation.
authors.affiliation: aDepartment of Biomedical Engineering, Kyung Hee University, Yongin bDepartment of Clinical Korean Medicine, Graduate School cDepartment of Radiology dSchool of Dance, Kyung Hee University, Seoul eMibyeong Research Center, Korea Institute of Oriental Medicine (KIOM), Daejeon, South Korea fDepartment of Systems and Biomedical Engineering, Faculty of Engineering, Cairo University, Giza, Egypt gDepartment of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Ramy S
authors.initials: RS
authors.lastname: Soliman
authors.forename: Sanghoon
authors.initials: S
authors.lastname: Lee
authors.forename: Seulgi
authors.initials: S
authors.lastname: Eun
authors.forename: Abdalla Z
authors.initials: AZ
authors.lastname: Mohamed
authors.forename: Jeungchan
authors.initials: J
authors.lastname: Lee
authors.forename: Eunyoung
authors.initials: E
authors.lastname: Lee
authors.forename: Meena M
authors.initials: MM
authors.lastname: Makary
authors.forename: Seung Min
authors.initials: SM
authors.lastname: Kathy Lee
authors.forename: Hwa-Jin
authors.initials: HJ
authors.lastname: Lee
authors.forename: Woo Suk
authors.initials: WS
authors.lastname: Choi
authors.forename: Kyungmo
authors.initials: K
authors.lastname: Park
mesh_terms: D000328:Adult; D000465:Algorithms; D005145:Face / Q000294:innervation; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007092:Imagination / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011597:Psychomotor Performance
chemical_list: D010100:Oxygen