https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/216 2026-07-04T11:48:41Z 2026-07-04T11:48:41Z Park, Seonghun Ha, Jisoo Cha, Ho-Seung Lee, Kyeong-Gu Im, Chang-Hwan https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/6209 2021-07-30T08:10:11Z 2021-02-22T00:00:00Z

Title: Development of an Online Home Appliance Control System for the Elderly Based on SSVEP-Based Brain-Computer Interface: A Feasibility Study Authors: Park, Seonghun; Ha, Jisoo; Cha, Ho-Seung; Lee, Kyeong-Gu; Im, Chang-Hwan Abstract: Brain-computer interface (BCI) is a technology that provides a direct communication channel between a user and the external environment using the user's brain activity. For the past decades, however, most BCI systems were tested with young people, even though the elderly are the primary target users of the BCI systems. Moreover, it has been frequently reported that a BCI system with the elderly showed significantly lower performance than that with young people. In the present study, to evaluate the feasibility of a steady-state visual evoked potential (SSVEP)-BCI-based home appliance control system, seventeen people over the age of 65 were recruited in an offline experiment in which their SSVEP responses were recorded while the visual stimuli were presented in an augmented reality (AR) environment via a see-through head-mounted display (HMD). The average classification accuracy of 94.1% and an information transfer rate (ITR) of 46.5 bits/min were achieved with respect to the window size of 3 s. Based on the results from the offline experiment, we tested the proposed online home appliance control system with a 65-year-aged female while the online experiment is still ongoing, increasing the number of the participants. © 2021 IEEE.

2021-02-22T00:00:00Z Park, Seonghun Cha, Ho-Seung Kwon, Jinuk Kim, Hodam Im, Chang-Hwan https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/10330 2021-08-02T09:31:40Z 2020-02-01T00:00:00Z

Title: Development of an Online Home Appliance Control System Using Augmented Reality and an SSVEP-Based Brain-Computer Interface Authors: Park, Seonghun; Cha, Ho-Seung; Kwon, Jinuk; Kim, Hodam; Im, Chang-Hwan Abstract: In this study, we implemented a new home appliance control system by combining a steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI), augmented reality (AR), and internet of things (IoT) technologies. The visual stimuli were presented on a see-through head-mounted display (HMD), while the recorded brain activity was analyzed to classify the control command, and the home appliances were controlled through IoT. The average classification accuracy of the SSVEP-BCI-based control system was 92.8%, with an information transfer rate (ITR) of 37.4 bits/min. The proposed system exhibited an excellent performance, surpassing the best results reported in previous studies regarding external device control based on BCI using an HMD as rendering device. ? 2020 IEEE.

2020-02-01T00:00:00Z Ahn, Jeongyeol Ryu, Juhyoung Lee, Sangjun Lee, Chany Im, Chang-Hwan Lee, Sang-Hun https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/15650 2021-08-02T12:33:07Z 2019-09-01T00:00:00Z

Title: Quantifying the Impacts of Transcranial Electrical Stimulation on Cortical Activity in Human Visual Cortex Authors: Ahn, Jeongyeol; Ryu, Juhyoung; Lee, Sangjun; Lee, Chany; Im, Chang-Hwan; Lee, Sang-Hun Abstract: Transcranial electrical stimulation (tES) has become a popular interventional method of stimulating human brains noninvasively. Despite reports of modulation of membrane potentials or BOLD responses by tES, it is far from conclusive whether and how tES affects neural activity. One prominent factor contributing to this inconclusion is that the baseline variability of noises intrinsic to measurements, which occur with diverse origins not just between but also within experimental sessions, have not been properly handled in previous studies. For example, the intrinsic variability of hemodynamic responses within and between scans causally confounds tES and thus complicates the attribution of observed effects in BOLD. To overcome this problem, we developed an experimental protocol that allows for statistically dissecting tES effects and other intrinsic noises in BOLD activity. By applying this protocol to human visual cortex, we demonstrate that tES induces substantial changes not only in the temporal dynamics of hemodynamic response function (HRF) but also in cortical population responses to dynamic stimuli, which cannot be reduced to the changes in HRF. Our findings imply that tES, when applied in protocols with statistical rigor and power, can manifest its impacts on BOLD signals in much more complicated and nuanced ways than previously reported.

2019-09-01T00:00:00Z Kim, Yong-Wook Kim, Sungkean Jin, Min Jin Im, Chang-Hwan Lee, Seung-Hwan https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/20957 2021-08-02T15:35:35Z 2019-04-01T00:00:00Z

Title: Low frequency alpha (8-10 Hz) activity correlated with inhibitory behavior Authors: Kim, Yong-Wook; Kim, Sungkean; Jin, Min Jin; Im, Chang-Hwan; Lee, Seung-Hwan Abstract: Introduction Alpha frequency of EEG and the default mode network (DMN) are predominantly activated during resting-state. Also, alpha frequency power is known to be related with inhibitory function. This study investigated the neuropsychological characteristics of alpha band power and alpha DMN at resting state. Methods Resting-state EEG, go/nogo ERP/behavioral data, and psychological measures were examined in a total of 101 healthy individuals. Relative alpha (8-12 Hz), low-alpha (8-10Hz), high-alpha (10-12Hz) powers were calculated from the resting-state EEG data. Source activations of 25 DMN regions and their global/nodal network measures (clustering coefficient(CC), path length(PL), efficiency, strength, and eigenvector centrality(EC)) were also calculated. Psychological measures included the Gray's behavioral inhibition/behavioral activation scale (BIS/BAS), the Barratt impulsivity scale (BIS), and the Conner’s adult ADHD rating scale (CAARS). Individuals were divided into 3 groups (low, middle, high) based on the level of power of each total/low/high-alpha frequency band. Results Significant group differences were found in low-alpha frequency power. The high group had significantly higher BIS score (behavior inhibition), significantly higher levels of global/nodal CC, efficiency, and strength, and a significantly lower PL at all region after Bonferroni correction compared to low and middle group. BIS inhibition was positively correlated with global/nodal CC, efficiency, and strength, and negatively correlated with global PL. Conclusions Our study revealed that low frequency alpha power is specifically related with inhibitory function. The results also suggest that DMN of low alpha frequency band could be a potential candidate of biological marker of inhibitory function.

2019-04-01T00:00:00Z