Human–computer interfaces with regional lower and upper alpha frequencies as on-line indexes of mental activity

The focus of this study involves the assessment of EEG signals to investigate mental activity associated with computer tasks when using two different interfaces. Eight subjects were used to contrast the mental activity associated with a visuo-spatial and a verbal task involving two human–computer interfaces: keyboard and mouse. To compare task difficulty, the mean lower alpha (8–10 Hz) and upper alpha (11–13 Hz) activities at the occipital, temporal, and frontal regions were used to analyze the data. Results revealed that there were differences in hemispheric activation in the lower and upper alpha wavebands. An interaction effect hemisphere by site was found at the temporal sites in the upper alpha band. Furthermore, an interaction effect task by computer interface was found at the temporal sites in the lower alpha waveband. Based on this study, lower and upper alpha activities appear to be valid measures to identify interfaces that are best matched to computer tasks. This type of research will allow the design of user-friendly human–computer interfaces.