13
Cerebral Spectral Perturbation during Upper Limb Diagonal Movements
DOI: http://dx.doi.org/10.5772/intechopen.88337
their eyes [28–30]. Beta desynchronization has been typically observed during the
execution of voluntary movement [31, 32] and during sensorimotor processing
[33]. After the conclusion of a voluntary movement, beta synchronization called
“post-movement beta rebound” has been observed over the sensorimotor cortex
[34, 35]. Other studies have suggested that beta is also involved in a large range of
cognitive, emotional, and attentional processing [36–39].
1.3 Aim of this study
Despite the fact that movement along the diagonal axis has been seen as a benefit
in different motor and cognitive rehabilitation protocols, none of the studies we are
aware of have investigated the neural correlates of diagonal movement during the
actual movement performance. Therefore, we aimed to observe the electrophysiological correlates of diagonal movements and compare them to a control condition
such as vertical movement. We hypothesized that diagonal movements compared
to vertical movements require more computational effort and motor control to be
well executed. This should result in increased theta, in decreased alpha due to an
increase in internalized attention, and finally in a modulation of beta tied to the
start and the end of each movement.
2. Methods
2.1 Participants and design
Eleven right-handed healthy participants (six males; mean age 40.3 years; SD
9.22) volunteered to take part in the study. All participants had normal or correctedto-normal vision, and they declared to not suffer from any psychiatric or physical
disease that could interfere with their performance.
The research took place in the Research Institute for Neuroscience, Education, and
Didactics of the Patrizio Paoletti Foundation. The participants signed an informed
consent. The study was approved by the ethics committee of Bar-Ilan University.
Before each experimental session, participants performed a training phase in
which they learned to perform correctly the movements required for the experiment. During the experimental session, EEG recording was conducted during the
performance of diagonal and vertical movements with both arms at the same time
in an antiphase movement (i.e., each arm moved jointly with the other arm starting
from the opposite side of the body and moving toward the opposite direction along
the same axis; for a clear explanation, see Figure 1).
2.2 Paradigm
Participants performed a total of 320 rhythmical movements with both arms
while sitting in a chair. Movements were divided into eight blocks. Each block
consisted in 40 rhythmical continuous movements paced by an external sound. We
used a 440 Hz tone with a duration of 100 ms, presented with the pace of 1 Hz (i.e.,
one sound each second), in order to guide the movements.
At the beginning of each block, participants had to keep one arm in the upper
position and the other one in the lower position (see Figure 1). Then, in line with
the start of the pacing sounds, they had to move their arms along the vertical or
diagonal axis, according to the condition of the block. A total of 20 consecutive trials were used in each block. Each trial lasted 2 s. Therefore, each trial was composed
of two sounds (i.e., two movements). The participants were instructed to perform
Cerebral Spectral Perturbation during Upper Limb Diagonal Movements
DOI: http://dx.doi.org/10.5772/intechopen.88337
their eyes [28–30]. Beta desynchronization has been typically observed during the
execution of voluntary movement [31, 32] and during sensorimotor processing
[33]. After the conclusion of a voluntary movement, beta synchronization called
“post-movement beta rebound” has been observed over the sensorimotor cortex
[34, 35]. Other studies have suggested that beta is also involved in a large range of
cognitive, emotional, and attentional processing [36–39].
1.3 Aim of this study
Despite the fact that movement along the diagonal axis has been seen as a benefit
in different motor and cognitive rehabilitation protocols, none of the studies we are
aware of have investigated the neural correlates of diagonal movement during the
actual movement performance. Therefore, we aimed to observe the electrophysiological correlates of diagonal movements and compare them to a control condition
such as vertical movement. We hypothesized that diagonal movements compared
to vertical movements require more computational effort and motor control to be
well executed. This should result in increased theta, in decreased alpha due to an
increase in internalized attention, and finally in a modulation of beta tied to the
start and the end of each movement.
2. Methods
2.1 Participants and design
Eleven right-handed healthy participants (six males; mean age 40.3 years; SD
9.22) volunteered to take part in the study. All participants had normal or correctedto-normal vision, and they declared to not suffer from any psychiatric or physical
disease that could interfere with their performance.
The research took place in the Research Institute for Neuroscience, Education, and
Didactics of the Patrizio Paoletti Foundation. The participants signed an informed
consent. The study was approved by the ethics committee of Bar-Ilan University.
Before each experimental session, participants performed a training phase in
which they learned to perform correctly the movements required for the experiment. During the experimental session, EEG recording was conducted during the
performance of diagonal and vertical movements with both arms at the same time
in an antiphase movement (i.e., each arm moved jointly with the other arm starting
from the opposite side of the body and moving toward the opposite direction along
the same axis; for a clear explanation, see Figure 1).
2.2 Paradigm
Participants performed a total of 320 rhythmical movements with both arms
while sitting in a chair. Movements were divided into eight blocks. Each block
consisted in 40 rhythmical continuous movements paced by an external sound. We
used a 440 Hz tone with a duration of 100 ms, presented with the pace of 1 Hz (i.e.,
one sound each second), in order to guide the movements.
At the beginning of each block, participants had to keep one arm in the upper
position and the other one in the lower position (see Figure 1). Then, in line with
the start of the pacing sounds, they had to move their arms along the vertical or
diagonal axis, according to the condition of the block. A total of 20 consecutive trials were used in each block. Each trial lasted 2 s. Therefore, each trial was composed
of two sounds (i.e., two movements). The participants were instructed to perform