Non-primary motor areas in the human frontal lobe are connected directly to hand muscles

Recovery of motor function after intensive navigated transcranial magnetic stimulation: A case report of unexpected therapeutic effects

“…We believe this stimulation was effective in restoring motor function because it was also directed at the premotor cortex. It has only recently been suggested that the secondary motor cortex is susceptible to direct stimulation [6]. We have recently mapped 16 healthy subjects for premotor projections as well as investigated changes in premotor areas after tDCS to the primary motor area [7].…”

Respiratory, postural and spatio-kinetic motor stabilization, internal models, top-down timed motor coordination and expanded cerebello-cerebral circuitry: a review

“…Controversy exists as to whether the models so acquired are stored in the cerebellum , or cerebral cortex areas such as the parietal area . The actual submovements so scheduled for task mastered motor skills might be directly controlled from the cerebral cortex (Heffner and Masterton, 1983;Kuyper, 1958;Liscic et al, 1998;Ludlow, 2005;Maertens de Noordhout et al, 1999;Teitti et al, 2008), or involve in a hierarchical manner of delegation, lower areas in the supraspinal nervous system, such as the cerebellum and other subcortical areas (van der Linden et al, 2007), and/or, processes lower down in the spinal cord (Kimura et al, 2006;van der Linden et al, 2007). Related this top-down control, the supraspinal adjustment of long-latency (45-100 ms) reflexes can also draw upon the cerebello-cerebral internal models of limb dynamics (Kurtzer et al, 2008).…”

“…For example, the human cerebral cortex has considerably enhanced access to spinal motorneurons (Lemon, 2008) and so gained direct control over finger and hand muscles (Heffner and Masterton, 1983;Teitti et al, 2008), and lower limb ones (Maertens de Noordhout et al, 1999). Similarly humans show direct control over the larynx and face (Ghazanfar and Rendall, 2008;Kuyper, 1958;Liscic et al, 1998;Ludlow, 2005).…”

“…The reason for this, I suggest, is that in nonhuman animals, pulmonary pressure and the vocal tract are restricted by reflexes to articulating a limited set of evolved vocalizations. But because human vocal tract actions are "unlocked" from such reflexes in humans by direct cortical control (Ghazanfar and Rendall, 2008;Kuyper, 1958;Liscic et al, 1998;Ludlow, 2005;Teitti et al, 2008), it can be synchronized and motor coordinated in complex sequences of diverse and differently timed glottal, laryngeal and supralaryngeal movements. It is this ability to combine as independent motor elements glottal phonation, laryngeal/ supralaryngeal gesture and vocal tract modifications (Lofqvist and Gracco, 1999) with timed anticipatory motor adjustment that, could be responsible for enabling the human motor system to create, and then string together, its rich diversity of speech phones into spoken words (as noted in section 6.1.2.…”

Functional Electrical Therapy for Hemiparesis Alleviates Disability and Enhances Neuroplasticity

“…Silent period (SP) is an electrically quiescent period following the motor evoked potential (MEP) elicited by TMS when the target muscle is voluntarily activated and it also serves as one of the measures of cortical excitability . Navigated TMS utilizes individual brain magnetic resonance imaging (MRI) for accurate localization of stimuli and this feature is specifically useful when repeated measurements are performed (Ruohonen 2003;Teitti et al 2008;Säisänen et al 2011). Navigated TMS is able to visualize the induced electric field over MR images of the subject's brain.…”