Advances in Neural Signal Processing
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of development timing and that these two domains activate shared brain regions such as
the prefrontal cortex and cerebellum [2]. Specifically, it was observed that activity in the
prefrontal cortex increases when a motor task requires the maintenance of movement
information through execution, selection of relevant task-related motor information,
and inhibition of automated behavior that could compromise motor performance.
Yet very few studies have examined this issue. A rare exception regards the studies related to a rehabilitation protocol based on stretching exercise and joint mobility
called proprioceptive neuromuscular facilitation (PNF) [3]. This rehabilitation protocol also includes diagonal arm movements in order to promote strength, coordination,
functional motoricity, and movement initiation [4]. More recently, Moreira et al. [5]
studied cerebral electrophysiological activity after the performance of unimanual
diagonal arm movements as presented in the original PNF protocol. They observed an
increase of beta and alpha power within a frontoparietal network after performance.
They showed that this kind of motor activity could improve motoricity through
modulation of cerebral plasticity over frontoparietal regions, suggesting that improved
motor execution is directly linked to motor control in the central nervous system.
Over the last few years, we studied another motor task that involves diagonal
movements, named Quadrato Motor Training (QMT) [6–8]. QMT is a sensorimotor training based on step-by-step, whole-body movement in vertical, horizontal,
and diagonal directions. From the electrophysiological point of view, pre- and
post-EEG recording showed acute and chronic increase of theta and alpha power
and coherence over frontal, parietal, and temporal regions [9–11]. We hypothesized that it is especially the planning of diagonal movement which plays a crucial
role in the establishment of such a modulation of theta and alpha band activity.
However, it is difficult to disentangle and isolate the contribution of diagonal from
vertical and horizontal movement, and further studies in which EEG is recorded
during the execution of QMT should be performed. Thus, as a first step, in order
to examine the effects of diagonal movements, in the current study, we measured
cerebral activity during the performance of diagonal and vertical movements (DM
and VM, respectively), using EEG recording. Given the aforementioned literature,
particular focus was addressed to the theta, alpha, and beta frequency bands.
1.2 Brain oscillations, movement, and cognition
Theta (4–7 Hz) activity seems to be involved in different cognitive functions
such as sustained attention [12], spatial navigation [13], memory [14], meditative states/internalized attention [15], and creativity [16]. Importantly, all these
cognitive functions require integration from different cerebral regions in order
to produce effective outcomes. In fact, it was suggested that there is an inverse
relationship between the extent of a recruited cortical network and the elicited
oscillatory frequency during task performance [17]. For these reasons, theta is also
thought to support long-range integration and promotion of mental states related to
absorption and concentration [18–20].
Alpha activity (8–12 Hz) is considered a fundamental brain rhythm produced
in the occipital cortex which reflects cortical inactivity during relaxed wakefulness with closed eyes and reduced sensory and motor processing [21, 22]. Alpha
desynchronization has been observed during a task that requires the deployment of
attention toward specific targets or locations in space, suggesting that alpha could
play an important role in the management of attentional resources and sensory
perception [23–26]. Moreover, similar to theta, increased parietal alpha power has
been related to internal-directed attention [27].
Beta frequency (13–30 Hz) is classically related to active wakefulness. It was
observed as an oscillatory activity replacing alpha waves when individuals opened
12
of development timing and that these two domains activate shared brain regions such as
the prefrontal cortex and cerebellum [2]. Specifically, it was observed that activity in the
prefrontal cortex increases when a motor task requires the maintenance of movement
information through execution, selection of relevant task-related motor information,
and inhibition of automated behavior that could compromise motor performance.
Yet very few studies have examined this issue. A rare exception regards the studies related to a rehabilitation protocol based on stretching exercise and joint mobility
called proprioceptive neuromuscular facilitation (PNF) [3]. This rehabilitation protocol also includes diagonal arm movements in order to promote strength, coordination,
functional motoricity, and movement initiation [4]. More recently, Moreira et al. [5]
studied cerebral electrophysiological activity after the performance of unimanual
diagonal arm movements as presented in the original PNF protocol. They observed an
increase of beta and alpha power within a frontoparietal network after performance.
They showed that this kind of motor activity could improve motoricity through
modulation of cerebral plasticity over frontoparietal regions, suggesting that improved
motor execution is directly linked to motor control in the central nervous system.
Over the last few years, we studied another motor task that involves diagonal
movements, named Quadrato Motor Training (QMT) [6–8]. QMT is a sensorimotor training based on step-by-step, whole-body movement in vertical, horizontal,
and diagonal directions. From the electrophysiological point of view, pre- and
post-EEG recording showed acute and chronic increase of theta and alpha power
and coherence over frontal, parietal, and temporal regions [9–11]. We hypothesized that it is especially the planning of diagonal movement which plays a crucial
role in the establishment of such a modulation of theta and alpha band activity.
However, it is difficult to disentangle and isolate the contribution of diagonal from
vertical and horizontal movement, and further studies in which EEG is recorded
during the execution of QMT should be performed. Thus, as a first step, in order
to examine the effects of diagonal movements, in the current study, we measured
cerebral activity during the performance of diagonal and vertical movements (DM
and VM, respectively), using EEG recording. Given the aforementioned literature,
particular focus was addressed to the theta, alpha, and beta frequency bands.
1.2 Brain oscillations, movement, and cognition
Theta (4–7 Hz) activity seems to be involved in different cognitive functions
such as sustained attention [12], spatial navigation [13], memory [14], meditative states/internalized attention [15], and creativity [16]. Importantly, all these
cognitive functions require integration from different cerebral regions in order
to produce effective outcomes. In fact, it was suggested that there is an inverse
relationship between the extent of a recruited cortical network and the elicited
oscillatory frequency during task performance [17]. For these reasons, theta is also
thought to support long-range integration and promotion of mental states related to
absorption and concentration [18–20].
Alpha activity (8–12 Hz) is considered a fundamental brain rhythm produced
in the occipital cortex which reflects cortical inactivity during relaxed wakefulness with closed eyes and reduced sensory and motor processing [21, 22]. Alpha
desynchronization has been observed during a task that requires the deployment of
attention toward specific targets or locations in space, suggesting that alpha could
play an important role in the management of attentional resources and sensory
perception [23–26]. Moreover, similar to theta, increased parietal alpha power has
been related to internal-directed attention [27].
Beta frequency (13–30 Hz) is classically related to active wakefulness. It was
observed as an oscillatory activity replacing alpha waves when individuals opened