Imitation encourages empathic capacity toward other individuals with physical disabilities.

Many people have difficulty empathizing with others who have dissimilar characteristics, such as physical disabilities. We hypothesized that people with no disabilities imitating the movements of individuals with disabilities could improve the empathic capacity toward their difficulties. To evaluate this hypothesis, we used functional magnetic resonance imaging to measure the neural activity patterns of 26 healthy participants while they felt the difficulties of individuals with hemiplegia by adopting their perspective. The participants initially either imitated or observed hemiplegic hand movements shown in video clips. Subsequently, the videos were rewatched and their difficulties were rated. Analysis of the subjective rating scores indicated that after imitating the hemiplegic movements, the participants felt into the difficulties of hemiplegia better than if they simply observed them. The cross-validation approach of multivoxel pattern analyses demonstrated that the information regarding the effect of imitation on empathizing with the difficulties was represented in specific activation patterns of brain regions involved in the mirror neuron system and cognitive empathy by comparing to other conditions that did not contain the information. The cross-classification approach detected distinct activation patterns in the brain regions involved in affective and cognitive empathy, commonly while imitating the hemiplegic movements and subsequently feeling them. This indicated that the common representation related to these two types of empathy existed between imitating and feeling the hemiplegic movements. Furthermore, representational similarity analysis revealed that activity patterns in the anterior cingulate cortex linked to affective empathy tuned to the subjective assessment of hemiplegic movements. Our findings indicate that imitating the movements of individuals with hemiplegia triggered the affective empathic response and improved the cognitive empathic response toward them. The affective empathic response also linked the subjective assessment to the difficulties of hemiplegia, which was especially modulated by the experience of imitation. Imitating the movements of individuals with disabilities likely encourages empathic capacity from both affective and cognitive aspects, resulting in people with no disabilities precisely feeling what they are feeling.

Immediate effects of visual-motor illusion on resting-state functional connectivity.

Visual-motor illusion (VMI) is to evoke a kinesthetic sensation by viewing images of oneself performing physical exercise while the body is at rest. Previous studies demonstrated that VMI activates the motor association brain areas; however, it is unclear whether VMI immediately alters the resting-state functional connectivity (RSFC). This study is aimed to verify whether the VMI induction changed the RSFC using functional near-infrared spectroscopy (fNIRS). The right hands of 13 healthy adults underwent illusion and observation conditions for 20 min each. Before and after each condition, RSFC was measured using fNIRS. After each condition, degree of kinesthetic illusion and a sense of body ownership measured using the Likert scale. Our results indicated that, compared with the observation condition, the degree of kinesthetic illusion and the sense of body ownership were significantly higher after the illusion condition. Compared with the observation condition, RSFC after the illusion condition significantly increased brain areas associated with kinesthetic illusion, a sense of body ownership, and motor execution. In conclusion, RSFC has become a biomarker that shows changes in brain function occurring due to VMI. VMI may be applied to the treatment of patients with stroke or orthopedic diseases.

First-person perspective sharpens the understanding of distressful physical feelings associated with physical disability: A functional magnetic resonance study.

We investigated whether observation of hand movements of people with hemiplegia by healthy individuals from the first-person perspective (FPP), compared to that from the third-person perspective (TPP), enables better understanding of disability-associated distress. We measured the neural activity of healthy individuals using functional magnetic resonance imaging while they observed hemiplegic movements from the FPP or TPP. Subjective assessment of the movements was determined with questionnaires. Compared to the TPP, the FPP elicited stronger activation in the inferior parietal lobule (IPL), right temporoparietal junction, and anterior cingulate cortex, which are associated with body representation, mentalization, and empathy, respectively. Enhanced IPL activity correlated positively with personal empathic traits. Observing movements of hemiplegic individuals from the FPP provided precise subjective understanding of the physically distressing aspects of their movements. These findings suggest that observing hemiplegic individuals from the FPP effectively improved observers' understanding of disability-associated distress via body representation, mentalization, and empathy systems.

Effects of pseudoexperience on the understanding of hemiplegic movements in physical therapists: An fMRI study.

Physical therapists (PTs) are required to obtain an accurate understanding of the physical and mental states of their patients through observational assessment. To perform comprehensive observational assessments of patients' movements, PTs likely need to engage their own neural systems involved in action understanding and theory of mind, such as the action observation network (AON) and the right temporoparietal junction (rTPJ). Both systems are modulated by the observer's actual experience with the observed movements. Although, most PTs do not have physical experience with neurological disabilities, they routinely examine hemiplegic movements in stroke patients, and are thus considered to have acquired pseudoexperience with hemiplegia. We hypothesized that the PTs' pseudoexperience with hemiplegia would modulate the neural system associated with the understanding of others to elaborately comprehend the physical and mental states associated with hemiplegia. To investigate our hypothesis, we recruited 19 PTs and 19 naïve participants (NPs) to undergo functional MRI (fMRI) for cortical activity measurement while viewing videos of hemiplegic (HHM) and non-hemiplegic (non-HHM) hand movements. The participants subsequently viewed the same videos again outside the MRI scanner, and evaluated the observed hand movements via a questionnaire. Compared to the NPs, the PTs showed greater activation in the AON and rTPJ while observing HHMs. Psychophysiological interaction analyses revealed increased connectivity between the rTPJ and AON when the PTs viewed the HHMs. Behavioral analyses further indicated that the PTs more accurately assessed feeling states associated with HHMs than did NPs. These findings suggest that the PTs' pseudoexperience modulates the AON and rTPJ, enabling them to better understand hemiplegia-associated feeling states.

Visuomotor effects of body part movements presented in the first-person perspective on imitative behavior.

Imitative stimuli presented from a first-person perspective (FPP) produce stronger visuomotor effects than those presented from a third-person perspective (TPP) due to the relatively greater response of the mirror neuron system (MNS) to FPP stimuli. Some previous studies utilizing TPP stimuli have reported no differences in MNS activity between moving and static bodies' stimuli. However, few studies have compared visuomotor effects of such stimuli when presented in the FPP. To clarify this issue, we measured cortical activation in 17 participants during a functional magnetic resonance imaging (MRI) imitation task involving three conditions: moving (a lifting finger was presented), static (an "X" appeared on a static finger), and control (an "X" appeared on a button). All stimuli were presented from the FPP or TPP. Participants were asked to lift the finger corresponding to the imitative stimulus. In the FPP condition, moving stimuli elicited greater MNS activation than static stimuli. Furthermore, such movement effects were stronger in the MNS and insula (a region associated with body-ownership) for FPP stimuli than for TPP stimuli. Psychophysiological interaction analysis revealed increased connectivity between the MNS and insula for moving stimuli in the FPP condition. These findings suggest that bodily movements presented in the FPP elicit a greater visuomotor response than static body presented in the FPP, and that the visuomotor effects of bodily movements were greater in the FPP condition than in the TPP condition. Our analyses further indicated that such responses are processed via the neural system underlying body-ownership. Hum Brain Mapp 38:6218-6229, 2017. © 2017 Wiley Periodicals, Inc.

Behavioral Advantages of the First-Person Perspective Model for Imitation.

Visuomotor information may be better conveyed through a first-person perspective than through a third-person perspective. However, few reports have shown a clear behavioral advantage of the first-person perspective because of the confounding factor of spatial stimulus-response compatibility. Most imitation studies have utilized visuospatial imitation tasks in which participants use the same body part as that used by the model, identified by its spatial position (i.e., the response action is predefined). In such studies, visuomotor information conveyed by the model does not appear to facilitate imitative behavior. We hypothesized that the use of the first-person perspective would facilitate more efficient imitative behavior than a third-person perspective when participants are asked to choose and reproduce an action identical to that of the model rather than to select the same body part; this task requires the analysis of both visual and motor information from the model rather than a simple assessment of spatial information. To test this hypothesis, we asked 15 participants to observe a model from two perspectives (first-person and third-person) with left or right hand laterality and to lift their index finger with an identical movement type (extension or flexion) as quickly as possible. Response latencies were shorter and fewer errors were made in trials using the first-person perspective than in those using the third-person perspective, regardless of whether the model used the right or left hand. These findings suggest that visuomotor information from the first-person perspective, without confounding effects of spatial information, facilitates efficient imitative behavior.

Imitation behavior is sensitive to visual perspective of the model: an fMRI study.

Imitation behavior and accompanying brain activity can be affected by the perspective of the model adopted. The present study was designed to understand the effect of a model's perspective in terms of the view (1st person vs. 3rd person) and the anatomical congruency of the limb between the model and the performer (congruent vs. incongruent). Eighteen young participants observed video clips of a model's finger-lifting behavior and lifted the same finger on their right hand as quickly as possible. Half of the video clips were filmed from the view of the participant (the 1st person view), whereas the other half were filmed from the perspective of facing a mirror (the 3rd person view). Each video clip depicted the finger lifting of the model's right (congruent) or left (incongruent) hand. Comparisons of the latency to imitate among the four perspective conditions showed significantly shorter latency for the 1st person-congruent and 3rd person-incongruent conditions. Hemodynamic measurements with functional magnetic resonance imaging showed that shorter latency was explained with less involvement of the brain areas that are activated when a task is relatively complex. The brain areas considered to be a part of neural substrates of imitation were significantly activated under the 1st person view conditions regardless of the hand congruency. These findings suggest that, although the latency to imitate finger lifting was determined by the complexity of the task induced with the model's perspective, imitation behavior seemed to be more effectively guided with the models filmed from the 1st person view.

Neural activation during imitation of movements presented from four different perspectives: a functional magnetic resonance imaging study.

The present study examined the effects of the perspective of movement presented for imitation in healthy volunteers, using functional magnetic resonance imaging (fMRI) to assess the magnitude and distribution of elicited brain activity. We sought to identify the pattern of brain activity associated with the performance of finger imitation tasks under four different imitation conditions. Video presentations of a hand and forearm performing random sequential contact between different fingers and the thumb were presented for imitation, while fMRI was recorded. The four types of model for imitation were: a hand and forearm pointing away from the subject, as if the subject were looking at their own limb (first-person perspective), from both anatomical (a right hand to be imitated by the subject's own right hand) and specular (a mirror image or "left" hand to be imitated by the subject's right hand) perspectives; and a hand/forearm pointing toward the subject, as if it was the hand of another person facing the subject (third-person perspective), from both anatomical (the opposite person's right hand) and specular (the opposite person's left hand) perspectives. In addition, participants completed a motor control task. The results revealed a significant difference in the magnitude of brain activation between the first- and third-person perspective conditions, suggesting that subjects used the first-person imitation model as a substitute for internal self-representation, thus requiring less effort. The first-person perspective anatomical model activated only the right posterior insula, recruiting significantly fewer brain regions than the other model types, compared with the control condition. These findings suggest that first-person anatomical perspective models may be optimal for ease of imitation in motor learning.