Miki Shibukawa

Comparison between event related potentials obtained by syllable recall tasks and by associative recall tasks

The final goal of this research is to establish some useful verbal communication systems between computers and persons, or between handicapped persons and normal persons. For a substantial progress toward the research goal, we investigate Event Related Potentials (ERPs for short) caused by Electroencephalograms (EEGs for short). By observing ERPs, we estimate recalled words, phrases, or sentences that may contain some homonyms or related words. In particular, we pay attention to the difference between ERPs caused by recalling a single syllable individually without other syllables and ERPs caused by recalling a syllable together with a word containing the syllable. From our observation of this difference, we believe that it may be useful to discuss the possibility of estimating a recalled word by combining ERPs caused by syllables.

An Effective ERP Model for Brain Computer Interface

The investigation of BCI (Brain Computer Interface) is particularly interesting for HCI research. Some of recent results concerning BCI have much contributed to the progress of HCI. In this paper we propose an effective ERP model that can reduce the difference among individuals in the process of repetitive tasks. Human brain reactions are quantified by ERPs (Event Related Potentials) that reflect the change of brain reactions through repetitive tasks. We discuss a method of how to even out the difference appeared in ERPs among individuals.

Studies on Imaging Methods to Realize Effective BCI through ERPs

This paper is to clarify the usefulness of imaging methods, such as imaging figures or words, for realization of effective Brain Computer Interaction (BCI). We design some experiments in which subjects engage in imaging figures or words. Event Related Potentials (ERPs) are measured through the experiments. Some variables of ERPs are introduced for the data analysis of our experimental. We consider ERPs as vectors of various components. Using the norms of the vectors, we discuss which imaging methods are suitable.

Fundamental Studies on Effective e-Learning Using Physiology Indices

In order to apply individual learning methods to an e-learning system, we need some appropriate measures to know the quantitative evaluation for the learning progress of each individual. The ratio of the number of correct answers to the number of questions is a simple measure of the achievement of the learner. However, such a simple measure may not accurately reflect the real progress of the learner. Event Related Potentials (ERPs for short) are measured from electroencephalograms (EEGs for short). We consider that ERPs may contain meaningful information about the level of the learners achievement. We had experiments measuring ERPs of subjects learning chemical formulae on an e-learning system. We try to characterize the relation among the learners achievement, hardness of learning, and the waveforms of his ERPs. This kind of characterizations may be useful for evaluating the learners achievement.

The Effectiveness of Feedback Control in a HCI System Using Biological Features of Human Beings

The purpose of this paper is to clarify the brain activities of human beings engaged in their tasks. Response time, correctness ratios, and Event Related Potentials (ERPs) are useful indexes of the brain activities of a subject at his task in the experiments. We analyze these indexes by a method called the Principle Component Analysis. Then we characterize the brain activities while he is engaged in the task. Finally we discuss the effectiveness of feedback control in a HCI system using these indexes.