Fig. 2

Non-Reflex Blink Count and Tap-Wise Distributions: a Boxplot. The figure shows the average number of non-reflex blinks after taps, comparing iPD patients (before and after medication) and HC. iPD patients showed a higher median value before and after medication compared to HC. The median value was decreased after medication, but statistically, the difference is not significant. However, the iPD patient’s results differ significantly from those of the HC; b Boxplot. The number of blinks of iPD patients before and after medication was calculated after each tap. Before medication, there is no in- or decrease in the number of blinks throughout the examination. After medication, iPD patients showed a higher number of blinks after the first 2–3 taps. After the third tap the median value decreased or stayed constant