Exploring the Motor System
Item is


Nilsson, Sofie1, Forfatter
Kyllingsbæk, Søren2, Vejleder
1Det Samfundsvidenskabelige Fakultet, Københavns Universitet, København, Danmark, diskurs:7001              
2Institut for Psykologi, Det Samfundsvidenskabelige Fakultet, Københavns Universitet, København, Danmark, diskurs:7012              
skjul Ophav
Vis Ophav


Ukontrollerede emneord: Motor system, grip force, TMS, fMRI
 Abstract: The ability to flexibly integrate information from the surrounding environment and adaptively respond to it is essential in everyday life. The dorsal premotor cortex (PMd) uses prior sensory information to prepare for motor output. This study employed a grasp-and-lift task and a combination of functional magnetic resonance imaging (fMRI) and continuous theta burst stimulation (cTBS) to further elucidate the role of PMd in motor control. 11 healthy human males (mean age 27) participated in the study. First, neuronal processing in PMd was disrupted using cTBS at 80% (inhibitory) or 30% (sham) of active motor threshold. Thereafter participants performed a grasp-and-lift task with arbitrary cues while the conditioning effects on brain activity were assessed with fMRI. In the task participants were asked to use information provided by a pre-cue (S1) that was correct in 75% of the trials to prepare for the execution of a lift in response to a go-cue (S2). If the S1 incorrectly prompted the lift of a light or heavy weight a consistent undershoot or overshoot in grip force was observed. Real cTBS selectively abolished grip force undershoot but not overshoot. In the sham cTBS condition, covariance analysis revealed significant correlation between optimal grip performance and grip-related activation of left rostral PMd. Performance was characterized by the individual amount of overshoot and undershoot, lower levels of both indicating better performance and vice versa. Real cTBS80% abolished this effect. Grip-related activation of left PMd was no longer predictive of optimal performance in the grasp-and-lift task. Instead, activity levels in right anterior insula predicted optimal performance after real cTBS. Our results provide additional information about the role of PMd during motor performance, suggesting a predictive role of PMd in coding for optimal performance in a grip force task requiring rapid adjustments of grip force levels. The compensatory effects of brain activation after real cTBS80% as well as further implications are discussed.
skjul Indhold
Vis Indhold


ThesisFinalSN.pdf (Hovedtekst)
Mime-type / størrelse:
application/pdf / 3MB
Copyright dato:
Copyright information:
De fulde rettigheder til dette materiale tilhører forfatteren.
skjul Filer
Vis Filer


Bogmærk denne post:
 Type: Speciale
Alternativ titel: A study combining Transcranial Magnetic Stimulation (TMS) and functional Magnetic Resonance Imaging (fMRI) to investigate brain areas involved in a grasp-and-lift task.
Alternativ titel: Motor systemet
Alternativ titel: En kombinerad TMS och fMRI studie med syfte att undersöka områden i hjärnan som är aktiva under en grip-och-lyft uppgift.
skjul Basal
Vis Basal


Vis Links


Sprog: English - eng
 Datoer: 2013-04-15
 Sider: -
 Publiceringsinfo: København : Københavns Universitet
 Indholdsfortegnelse: -
 Note: -
 Type: Speciale
skjul Detaljer
Vis Detaljer


Vis Kilde