Figure 4.

FFT on the Hofmeister dataset. Left: Spike characteristics due to different anion stimulation in the time domain shown by $t_{1/2}$. Right: Spike characteristics in the frequency domain shown by median of mean frequency, $f_{\text{mean}}$. The averaged median of mean frequency (shown with solid bar) shows a clear dependency on the stimulating anion, i.e. it decreases along the Hofmeister-order (here from left to right) except for the anion ${\mathrm{ClO}}_4^{-}$, which also showed its abnormality during the time-domain analysis. Additionally, the cross-cell standard error of mean of the median of $t_{1/2}$ and the median of mean frequency are denoted by the error bars. Bars represent the mean of the medians of t-half across multiple datasets, with error bars representing the standard error of the mean of the medians.