Participants will be instructed to participate in a handwriting experiment, which involves utilizing a Force Acquisition Pen (FAP) system and Near Infrared Spectroscopy (NIRS) to collect force data and cortical activation, respectively, during handwriting tasks. Children will be tasked with completing various assignments, such as tracing lines, writing numbers, and characters, among others. Additionally, assessments of motor ability and handwriting proficiency will be conducted using the Movement Assessment Battery for Children (MABC) and the Chinese Handwriting Evaluation Form (CHEF). The Pinch Holding Up Activity (PHUA) Test will also be administered to assess their sensorimotor ability.

FAP system was used to collect the kinetic data during the process of writing. During the experiment, children will be asked to perform some tasks: tracing line, writing numbers, writing Bopomofo, and writing characters. The force of thumb, index, middle fingers and pen tip will be recorded. This is able to reflect the motor control aspect of handwriting through a variety of parameters. The following parameters will be calculated: average force, max force ration, numbers of force fluctuation per second, … and so on.

The PHUA test is used to measure one's sensorimotor ability. Through calculating the parameters (max pinch force, max load force, force ratio … etc) to reflect one's ability to integrate sensory and produce a new output. A higher force ratio reflects a poorer sensorimotor ability.

The MABC test is used to measure children's motor ability, including fine motor, balance and aiming and catching ability. The score will transform into z score and rank score, to reflect child's performance. A higher score indicates a better motor ability.

The CHEF is a questionnaire developed to assess and confirm the handwriting difficulties of preschooler (the third year of kindergarten) and school-aged children (grade one to two of elementary school). The school-aged version includes 25 items within five dimensions of handwriting problem: legibility, accuracy, speed, pencil grip, and directionality; while the preschooler version includes 22 items within four dimensions of handwriting problem: legibility, function (accuracy and speed), pencil grip, and attitude. The score is rated by teachers, parents, or familiar professionals with a 5-point Likert scale. A larger score indicates more difficulty in handwriting.

The NIRS system measures changes in oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) as parameters to analyze cortical activation data. During handwriting, the cortical activation will be collected to observe which brain area activates more.

TONI is a test to evaluate one's nonverbal intelligence, without the influence of the confounding effects of linguistic or motor function. Children will conduct this test during screening phase.