Spss v21

For input-output and refractoriness testing, quantitative analyses were conducted on waveforms which were the average of four successive sweeps. In cases where more than one slice was used from a single rat, those multiple-slice data were averaged for that rat and used for the analysis. Two categories of inferential statistical tests were used to evaluate the effects of injury and CFZ on callosal CAPs. First, analyses conducted at single levels of stimulation were evaluated using ANOVA (SPSS v21) combined with Bonferroni posthoc tests, and where appropriate, effect size was estimated using the Cohen’s D statistic. Secondly, the significance of shifts in curves, measured in input-output or refractory analyses, was evaluated with the Mann-Whitney U test. A nonparametric approach was selected in the latter case, because homogeneity of variance requirements were not met when ranges of stimulus intensities were applied. Statistical analysis of WB data was also performed using SPSS v21. Raw relative optical density measures were first tested for normality (Kolmogorov-Smirnov statistic) and homogeneity of variance. Appropriate data were then analyzed with ANOVA, and Dunnett post hoc tests. The significance level, α = 0.05, was used for all inferential statistics, and averaged values are expressed as mean ± SEM.