**4. Action observation and motor learning**

Schmidt defined that motor learning is a "process of acquiring the capability for producing skilled actions" [26], and "the changes associated with practice and experiences, in an internal process that determines a person's capability for producing motor skill" [27]. Moreover, Guthrie stated that motor learning is a "relatively permanent change, resulting from practice or a novel experience, in the capability for responding" [28]. In other words, motor learning is

**Figure 7.** Cortical activation patterns in the action observation (AO), motor imagery (MI), and control (C) groups [34]. Average TRPow (task‐related power) changes with respect to resting baseline, within the two frequency bands showing significant group effects, were interpolated and projected onto an average brain cortical surface.

the capability acquired from practice and experience, and the change is relatively permanent. How can then action observation contribute to motor learning?

the observation of hand movements using EEG (**Figure 6**). A desynchronization of alpha and beta rhythms was observed in the central and parietal regions. Notably, there was a large post‐stimulus power rebound present in all bands. Furthermore, the velocity profile of the observed movement and beta band modulation correlated, indicating a direct matching of the

Schmidt defined that motor learning is a "process of acquiring the capability for producing skilled actions" [26], and "the changes associated with practice and experiences, in an internal process that determines a person's capability for producing motor skill" [27]. Moreover, Guthrie stated that motor learning is a "relatively permanent change, resulting from practice or a novel experience, in the capability for responding" [28]. In other words, motor learning is

**Figure 7.** Cortical activation patterns in the action observation (AO), motor imagery (MI), and control (C) groups [34]. Average TRPow (task‐related power) changes with respect to resting baseline, within the two frequency bands showing

significant group effects, were interpolated and projected onto an average brain cortical surface.

stimulus parameter to motor activity.

6 Electroencephalography

**4. Action observation and motor learning**

Motor imagery is similar to action observation. It is the mental simulation of movement with‐ out physical movement of body parts [29]. Action observation and motor imagery have been shown to share the same neural basis as that used for the execution of the actual physical movement [30]. However, the process of action observation and motor imagery are different. Action observation is a bottom‐up process (process from perception), while motor imagery is a top‐down process (process from memory). Nevertheless, these processes are not clearly divided, and a feed‐forward model was constructed by complementing these processes [31]. In addition, action observation has an effect of promoting motor imagery [32].

In the early stages of new complex motor learning, action observation is superior to motor imagery as a strategy for motor learning, as revealed by behavioral [33] and EEG data (**Figure 7**) [34]. Motor imagery is influenced by the environment and personal imaging abil‐ ity and requires mental effort. In contrast, action observation is easier to apply than motor imagery, despite targeting activation of the same neural network as motor imagery [35]. We have also reported that the left sensorimotor and parietal areas of the high‐motor learning group showed a greater decrease in the alpha‐2 and beta‐2 rhythms than those of the low‐ motor learning group during observation and execution. These results suggested that the decreases in the alpha‐2 and beta‐2 rhythms in these areas during observation and execution

**Figure 8.** Changes in EEG activity durings observation and execution of a motor learning task [36]. Alpha‐2 (A) and beta‐2 (B) rhythms in the left sensorimotor and parietal areas during action execution from the 1st trial to the 5th trial were significantly decreased in the high‐motor learning group compared with in the low‐motor learning group.

are associated with motor skill improvement (**Figure 8**) [36]. Accordingly, action observation may be an effective tool as an intervention method during the early stage of motor learning.
