The Activation and Walking Speed of the Prefrontal Cortex of the Elderly Mild Cognitive Impairment During Dual Task.

The goal of this observational study is to compare to investigate the effect of dual task performance on straight and curved walking in elderly people with mild cognitive impairment.

The main question\[s\] it aims to answer are:

* The purpose of this study was to investigate the effect of dual task performance on the activity of the prefrontal cortex in the elderly with mild cognitive impairment during straight and curved walking.
* The purpose of this study was to investigate the effect of dual task performance on gait speed during straight and curved walking in elderly people with mild cognitive impairment.

Participants will: For mild cognitive impairment 65 and older who can do dual tasks.

* single task (motor task) : an exercise task, which will perform a 10-meter walking test and a figure-eight walking test.
* double task (motor task + cognitive task) : planned to perform a motor task and a cognitive task together. The cognitive task is scheduled to be a simple calculation problem so that it can be performed without great difficulty while walking.

The goal of this observational study is to compare to investigate the effect of dual task performance on straight and curved walking in elderly people with mild cognitive impairment.

The main question\[s\] it aims to answer are:

* The purpose of this study was to investigate the effect of dual task performance on the activity of the prefrontal cortex in the elderly with mild cognitive impairment during straight and curved walking.
* The purpose of this study was to investigate the effect of dual task performance on gait speed during straight and curved walking in elderly people with mild cognitive impairment.

Participants will A total of 30 subjects will perform a single task (motor task) and a double task (motor task + cognitive task), four tasks per subject, and the order of examination will be randomly assigned. The subject's prefrontal cortex activity will be measured using fNIRS (NIRSIT, OBELAB).

The single task is an exercise task, which will perform a 10-meter walking test and a figure-eight walking test. The 10-meter walking test was developed to evaluate walking speed during short distance walking.

The total length was set to 14 m, and a distance of 2 m was placed at the beginning and end to avoid being affected by acceleration and deceleration. The figure-eight gait test requires a person to walk in a figure-eight shape around two cones placed as a tool to measure curved walking ability. In this study, in order to perform the exercise task at the same distance, a straight line of 14 m will be made into a random line and set in the shape of a figure 8.

Do not deviate more than 1 m from the object in the rotating section of the object. The dual task is planned to perform a motor task and a cognitive task together. The cognitive task is scheduled to be a simple calculation problem so that it can be performed without great difficulty while walking. The subject will perform a total of 3 repetitions and will have a 20-second break before starting each task.

Eligibility Criteria:
Inclusion Criteria:

* A person with a Korean version of the Simplified Mental Status Test (K-MMSE-2) score of 18-23.
* A person who can walk using an auxiliary device.

Exclusion Criteria:

* A person who cannot walk 3 meters back and forth or stand up from a sitting position
* A person sensitive to infrared lasers
* A person with impaired vision and hearing