P values represent probability that the associated r would have occurred by chance alone. Following the last treatment session, subjects were retested and rerated. Difference scores were created by subtracting the scores they obtained on each test and rating scale before the treatment began from those obtained after the termination of the treatment. Positive scores indicate improvement. Scores of zero reflect no change.
Negative scores indicate deterioration of performance.
For both test scores and average ratings, the Mann-Whitney U Test was used to determine if the differences obtained from the two groups were likely to be the result of chance alone, or whether they represented a real effect. In Table 2 we see that for the group exposed to the Hemi-Sync signal, all difference scores were, on the average, positive. By contrast, the average difference scores obtained by the group denied the Hemi-Sync signal were generally negative. Only in the case of the Digit Symbol Test, however, were the differences between the two groups significant, which is to say, not likely the result of chance. In Table 3 we find a similar pattern.