Control of one-dimensional cursor movement by noninvasive brain-computer interface in humans

Abstract

Noninvasive brain-computer interface (BCI), using electroencephalogram (EEG) that records from scalp, could provide a new non-muscular channel for sending messages and command to the external world. The objectives of this study are to determine parameters that will drive cursor in BCI using noninvasive EEG signal and to control one dimensional cursor movement using the extracted parameters. This experimental-based study involved six normal subjects aged from 20 to 26 years old. Subjects were asked to perform tasks in two condition i.e. control condition and task condition. In the control condition, subjects were required to relax (resting) and fix their eyes on the centre of the screen without image displayed on the screen. In the task condition subjects were tasked to imagine a movement to move the cursor on the screen towards the target. These control and task conditions were repeated four times and each condition lasted for 10 seconds. Using Fast Fourier Transform, data in frequency domain for control and task have been obtained and analyzed in two of time interval of 1024 ms and 512 ms. Frequency is divided into six groups, i.e. delta band (0-4 Hz), theta band (4-7 Hz), alpha band (8-13 Hz), beta band (13-30 Hz), gamma band (31-50 Hz) and high gamma band (>51 Hz). Each frequency band in all frequencies of the task condition has been compared to the control condition. The present study finds optimum difference in delta frequency band between resting and active imagination at the parietal region. Furthermore, the parietal region is associated with sensory interaction and could be one of the input regions to control cursor movement. However, it is found that the delta frequency band is only applicable to a specific one-dimensional cursor movement as any imagination may produce the same results. Nevertheless, this study provides a platform for a more advance two-dimensional cursor movement study.