An objective of the present invention is to provide a brain-computer interface text input apparatus which allows an ERP based text input system to rapidly recognize correct letter (target text) and maintain high recognition rate of a system using probability based visual simulation dynamic optimization technology presenting optimized stimulation to a user based on classifier results updated each time minimal stimulation is repeated, a method thereof. The brain-computer interface text input apparatus using probability based visual simulation dynamic optimization technology comprises: a memory to store a program for performing a brain-computer interface text input method; and a program to executing the program. The processor performs: a first step of presenting a visual stimulation group configured by a character array including a plurality of characters as a predetermined stimunaiton number by executing the program and measuring a brain signal of a measured person generated corresponding to each character to detect a probability of a target character by each character; a second step of excluding an optional character from a vitual stimulation group when a probability of a detected optional character is significantly lower than a probability of remaining characters to select the remaining characters as a candidate character group; a third step of determining wheter to continuously measure a brain signal according to a reset dynamic stopping criterion; and a fourth step of relocating a candidate character group as each flash group configuring the visual stimulation group when it is determined to continously measure the brain signal. Until stopping measuring of the brain signal in the third step, the first step to the fourth step are repeated N times. One of candidate character groups in (N-1) times is determined as a target character.
- BRAIN-COMPUTER INTERFACE SPELLING APPARATUS AND METHOD USING DYNAMIC OPTIMIZATION TECHNOLOGY OF VISUAL STIMULATION BASED ON PROBABILITY