Most children can naturally engage in play and by this, develop skills while interacting with their peers and toys. However, children with Autism Spectrum Disorder (ASD) often show impairments in play skills which result in limited opportunities for interaction with others and the learning of social skills. In this regard, robotic devices/toys that can provide simple and attractive indications are advantageous to engage children with ASD in play activities that require social and interaction skills. This project proposes a new interaction method using paired robotic devices called COLOLO to facilitate a fundamental exchange of intention in communication so-called turn-taking. These tangible devices are designed to sense the user’s manipulation, send a message to the paired device, and display visual cues for assisting children to achieve turn-taking through play. On the sessions with COLOLO there are two devices, one held by the therapist and one by the child, and they take turns to manipulate the toys and change their colors. In this article, two experimental conditions or interaction rules: the “two-sided lighting rule” and the “one-sided lighting rule" were introduced. The two interactions rules differ from each on the way the devices used the visual cues to indicate the turn-holder. The effect of each interaction rule on children’s turn-taking behaviors was investigated through an experimental study with four children with ASD. From the results, we found that with the one-sided lighting rule participants tended to shift their gaze more and to decrease the failed attempts of turn-taking. The discussion covers the possibilities of using paired devices to describe participants’ behaviors related to turn-taking quantitatively.

The simulation study investigated the relationship between the local linear trend model’s data-comparison accuracy, baseline-data variability, and changes in level and slope after introducing the N-of-1 intervention. Contour maps were constructed, which included baseline-data variability, change in level or slope, and percentage of non-overlapping data between the state and forecast values by the local linear trend model. Simulation results showed that baseline-data variability and changes in level and slope after intervention affect the data-comparison accuracy based on the local linear trend model. The field study investigated the intervention effects for actual field data using the local linear trend model, which confirmed 100% effectiveness of previous N-of-1 studies. These results imply that baseline-data variability affects the data-comparison accuracy using a local linear trend model, which could accurately predict the intervention effects. The local linear trend model may help assess the intervention effects of effective personalized interventions in precision rehabilitation.

To examine the reliability and validity of eye–hand coordination pointing with pencil test (EHCPPT), which evaluates the spatial and temporal displacement of rhythmic movements. One hundred and thirty-five older adults participated in our study. Reproducibility of the EHCPPT was assessed by the participants tapping on the center of the circles using a tablet pen in response to 2 types of stimulus sound sequences (Test A and B) across 2 separate trials, the first and second half. Construct validity was assessed by comparison in the distances between ultimate and current processing abilities, based on the spatial and temporal displacement relationship across Test A and Test B. Concurrent validity was assessed by examining the relationship between the distances between ultimate and current processing abilities and the motor and cognitive functions. Spatial and temporal displacements showed an excellent intraclass correlation coefficient in both Tests A and B of EHCPPT. The distance between ultimate and current processing ability, based on the relationship of spatial and temporal displacement, was significantly shorter in Test A compared to Test B. Spatial and temporal displacements were correlated with motor and cognitive functions. The spatial and temporal displacements of EHCPPT indicated reproducibility and validity in older adults. The EHCPPT may serve as a rhythmic movement reflecting motor and cognitive functions.

Paired associative stimulation (PAS) increases and decreases cortical excitability in primary motor cortex (M1) neurons, depending on the spike timing-dependent plasticity, i.e., long-term potentiation (LTP)- and long-term depression (LTD)-like plasticity, respectively. However, how PAS affects the cortical circuits for the agonist and antagonist muscles of M1 is unclear. Here, we investigated the changes in the LTP- and LTD-like plasticity for agonist and antagonist muscles during PAS: 200 pairs of 0.25-Hz peripheral electric stimulation of the right median nerve at the wrist, followed by a transcranial magnetic stimulation of the left M1 with an interstimulus interval of 25 ms (PAS-25 ms) and 10 ms (PAS-10 ms). The unconditioned motor evoked potential amplitudes of the agonist muscles were larger after PAS-25 ms than after PAS-10 ms, while those of the antagonist muscles were smaller after PAS-25 ms than after PAS-10 ms. The γ-aminobutyric acid A (GABA_A)- and GABA_B-mediated cortical inhibition for the agonist and antagonist muscles were higher after PAS-25 ms than after PAS-10 ms. The cortical excitability for the agonist and antagonist muscles reciprocally and topographically increased and decreased after PAS, respectively; however, GABA_A and GABA_B-mediated cortical inhibitory functions for the agonist and antagonist muscles were less topographically decreased after PAS-10 ms. Thus, PAS-25 ms and PAS-10 ms differentially affect the LTP- and LTD-like plasticity in agonist and antagonist muscles.