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.