Presslease

2025/10/15

The

University of Tsukuba

announced groundbreaking research results showing that the wearable cyborg

HAL (Hybrid Assistive Limb)

activates brain plasticity through the user’s own intention to move. This is the

world’s first brain-imaging study

to demonstrate the direct influence of a wearable cyborg on human brain activity.

The research confirms that “

cyborg-type robots can enhance neuroplasticity through the wearer’s voluntary drive

.” Using HAL, the study revealed that the higher motor areas of the brain become significantly more active when movement is performed in sync with the user’s intention.

Study Overview

The research team at the

University of Tsukuba

measured brain activity during upper-limb movements performed while wearing HAL, using

functional near-infrared spectroscopy (fNIRS)

to visualize and quantify neural responses.

Twenty healthy adult participants performed the movement of raising their arm under three conditions:

  1. Voluntary movement

    – lifting the arm independently

  2. Active robotic assistance

    – HAL moves in response to the wearer’s voluntary intention

  3. Passive robotic assistance

    – HAL moves without the wearer’s intention

Under both the voluntary and active-assist conditions, significant activation was observed in the

higher motor areas

, including the

premotor cortex

. In contrast, brain activation was markedly reduced under the passive condition. These findings provide compelling evidence that

the presence of voluntary intention directly impacts brain activity

.

HAL and the iBF Principle

HAL operates on the

interactive Bio-Feedback (iBF) principle

, detecting bioelectrical signals from the user’s nervous system that reflect the intention to move. The system drives robotic motion accordingly, while sensory feedback from proprioceptors such as muscle spindles is simultaneously transmitted back to the brain.

This interactive loop between the brain and body promotes

neural activation and plasticity

, suggesting that HAL may facilitate

functional improvement and neural regeneration

. The study demonstrated that brain regions responsible for motor control were significantly more active when movements were performed in coordination with HAL and the user’s will to move.

About the Study

The research was conducted by a team from the University of Tsukuba and published in IEEE Transactions on Neural Systems and Rehabilitation Engineering (June 2025).

https://www.tsukuba.ac.jp/journal/pdf/p20250707143000.pdf