High-loading variables were further subjected to t-test statistics and evaluated on single ion images. Post hoc power analyses and T statistics were performed in Matlab using the sampsizepwr function (Statistics and Machine Learning Toolbox). Power analysis was based on two-sample pooled t-test, after assessing for normally distributed data, with unknown standard deviation and equal variances. Mean and standard deviation of sample values from image segmented arrays were used. While we acknowledge that the usefulness of post hoc power analyses is controversial, we included these results as retrospective assessments to safeguard against experimental error.