CSF levels of sphingomylein:ceramide ratios for acyl chain lengths of C18:0 are associated with performance on immediate recall, delayed recall, and trial 5 of the Rey Auditory Verbal Learning Test. Correlations for CSF levels of the sphingomyelin:ceramide ratio for C18:0 and (A) total, (B) trial 5, (C) immediate recall, and (D) delayed recall on the Rey Auditory Verbal Learning Test. Correlations for CSF levels of the sphingomylein:ceramide ratio for C18:0 and (D) copy and (E) recall on the Rey Complex Figure Test. The correlation coefficient (b) and exact significance levels (p) are indicated in insets. For D, excluding the data point in the box had little impact on the association (b = −0.32 compared with p = 0.353). n = 31 subjects. Linear regressions with age- and education-adjusted z-scores for each cognitive test.