  It has been shown that blinks occur not only to moisturize eyes and as a
defensive response to the environment, but are also caused by mental processes.
In this paper, we investigate statistical characteristics of blinks and blink
rate variability of 11 subjects. The subjects are presented with a
reading/memorization session preceded and followed by a resting session. EEG
signals were recorded during these sessions. The signals from the two front
electrodes were then analyzed, and times of the blinks were detected. We
discovered that compared to the resting sessions, reading session is
characterized by a lower number of blinks. However, there was no significant
difference in standard deviation in the blink rate variability. We also noticed
that in terms of complexity measures, the blink rate variability is located
somewhere in between white and pink noises, being closer to the white noise
during reading. We also found that the average of inter-blink intervals
increases during reading/memorization, thus longer inter-blink intervals could
be associated with a mental workload.
