Involvement of the Rostromedial Prefrontal Cortex in Human-Robot Interaction: fNIRS Evidence From a Robot-Assisted Motor Task

Duc Trung Le; Kazuki Watanabe; Hiroki Ogawa; Kojiro Matsushita; Naoki Imada; Shingo Taki; Yuji Iwamoto; Takeshi Imura; Hayato Araki; Osamu Araki; Taketoshi Ono; Hisao Nishijo; Naoto Fujita; Susumu Urakawa

doi:10.3389/fnbot.2022.795079

Involvement of the Rostromedial Prefrontal Cortex in Human-Robot Interaction: fNIRS Evidence From a Robot-Assisted Motor Task

Front Neurorobot. 2022 Mar 17:16:795079. doi: 10.3389/fnbot.2022.795079. eCollection 2022.

Authors

Duc Trung Le^{1

2}, Kazuki Watanabe¹, Hiroki Ogawa¹, Kojiro Matsushita³, Naoki Imada⁴, Shingo Taki⁴, Yuji Iwamoto⁴, Takeshi Imura⁵, Hayato Araki⁶, Osamu Araki⁶, Taketoshi Ono⁷, Hisao Nishijo^{7

8}, Naoto Fujita¹, Susumu Urakawa¹

Affiliations

¹ Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
² Department of Neurology, Vietnam Military Medical University, Hanoi, Vietnam.
³ Department of Mechanical Engineering, Facility of Engineering, Gifu University, Gifu, Japan.
⁴ Department of Rehabilitation, Araki Neurosurgical Hospital, Hiroshima, Japan.
⁵ Department of Rehabilitation, Faculty of Health Sciences, Hiroshima Cosmopolitan University, Hiroshima, Japan.
⁶ Department of Neurosurgery, Araki Neurosurgical Hospital, Hiroshima, Japan.
⁷ Department of System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan.
⁸ Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama, Japan.

Abstract

Assistive exoskeleton robots are being widely applied in neurorehabilitation to improve upper-limb motor and somatosensory functions. During robot-assisted exercises, the central nervous system appears to highly attend to external information-processing (IP) to efficiently interact with robotic assistance. However, the neural mechanisms underlying this process remain unclear. The rostromedial prefrontal cortex (rmPFC) may be the core of the executive resource allocation that generates biases in the allocation of processing resources toward an external IP according to current behavioral demands. Here, we used functional near-infrared spectroscopy to investigate the cortical activation associated with executive resource allocation during a robot-assisted motor task. During data acquisition, participants performed a right-arm motor task using elbow flexion-extension movements in three different loading conditions: robotic assistive loading (ROB), resistive loading (RES), and non-loading (NON). Participants were asked to strive for kinematic consistency in their movements. A one-way repeated measures analysis of variance and general linear model-based methods were employed to examine task-related activity. We demonstrated that hemodynamic responses in the ventral and dorsal rmPFC were higher during ROB than during NON. Moreover, greater hemodynamic responses in the ventral rmPFC were observed during ROB than during RES. Increased activation in ventral and dorsal rmPFC subregions may be involved in the executive resource allocation that prioritizes external IP during human-robot interactions. In conclusion, these findings provide novel insights regarding the involvement of executive control during a robot-assisted motor task.

Keywords: Hybrid Assistive Limb (HAL®); NIRS (near-infrared spectroscopy); assistive exoskeleton robot; executive function; frontal pole; prefrontal cortex (PFC).