Dynamic Difficulty Adjustment in a P300 Speller Task for Attention Training

Overview

This study compares different adaptation approaches in a P300-based BCI neurofeedback training to improve short-term attention. Participants will spell several words on a computer by focusing on a letter on the screen while their brain activity is recorded (P300 speller). The difficulty of this task will be adapted to train their attention. Their cognitive abilities will be evaluated using a random dot kinematogram, where they are asked to indicate the direction a fraction of moving dots on the computer screen is going in, before and after the training to analyse any improvements. Questionnaires will be used to compare the perceived task load of the different adaptation approaches.

Healthy participants will complete several runs in a P300-speller task, where the number of flashes per row and column is progressively adapted to their performance (in control group 1 and experimental group) or chosen randomly (in control group 2). Decreasing the number of flashes per row and column makes it harder for the computer to identify the letter the participant is focusing on, which encourages them to improve their focus to maintain their performance. The number of flashes can therefore be interpreted as the task difficulty of the P300 speller task. The participants will complete a continuous version of the random dot kinematogram, where a fraction of incoherently moving dots will start moving coherently. The participants are asked to indicate which direction these dots are moving in. This task is completed before and after the P300 speller training, so that response times in the task can be compared. To evaluate the perceived task load of the different adaptation approaches, the participants will complete a questionnaire about fatigue and boredom before and after the training session, as well as the NASA Task Load Index at the end of the experiment.