Estimations of viewed object sizes using a single-channel of visual evoked potentials

In order to create reading support systems, the feasibility of using viewed size predictions was evaluated using features of EEG waveforms. Viewer's occipital single channel potentials were measured while six sizes of Landolt circles were shown. Features such as series of potentials, latencies of P1 and N1 peaks, and 5 vectors of Fourier descriptors (FD) were extracted from the EEG waveforms. The performances of 6-classes were classified and compared across sets of each feature and combinations of these. The EEG waveforms were transformed when accumulated. The five-fold cross validation rate for all sets of features increased with the number of EEGs accumulated. The accuracy of a feature combination for P1, N1 and FD is significant when the waveform is measured twice. This result suggests that the size of objects being viewed can be predicted using a set of features which can be extracted from a single channel EEG waveform recorded at an occipital electrode.