  Event-related potential (ERP) speller can be utilized in device control and
communication for locked-in or severely injured patients. However, problems
such as inter-subject performance instability and ERP-illiteracy are still
unresolved. Therefore, it is necessary to predict classification performance
before performing an ERP speller in order to use it efficiently. In this study,
we investigated the correlations with ERP speller performance using a
resting-state before an ERP speller. In specific, we used spectral power and
functional connectivity according to four brain regions and five frequency
bands. As a result, the delta power in the frontal region and functional
connectivity in the delta, alpha, gamma bands are significantly correlated with
the ERP speller performance. Also, we predicted the ERP speller performance
using EEG features in the resting-state. These findings may contribute to
investigating the ERP-illiteracy and considering the appropriate alternatives
for each user.
