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Efficacy of Neurofeedback on Adults with Attentional Deficit
and Related Disorders

David A. Kaiser EEG Spectrum, Inc. Encino, CA
December 1997

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RESULTS
Repeated measures univariate analyses of variance (ANOVA) were used to evaluate the effect of neurofeedback training on four dependent measures of the TOVA: Inattention (percent omission), Impulsivity (percent commission), Response Time, and Response Variability. Low scores were truncated at four standard deviations below normal (i.e., 40 points). Mean pre- and post-training TOVA scores are presented in Table 1.

Table 1. Mean standard scores for TOVA subtests before and after 20 or more neurofeedback sessions for 142 adults with attention problems.

A significant interaction of treatment and TOVA measure was found, F(2,231)=11.780, p < .001. As shown in Figure 1, neurofeedback training produced significant improvement in inattention scores; F(1,141)= 17.273, p < .001; impulsivity scores, F(1,141)= 85.760, p < .001; and variability of response time, F(1,141)= 26.570, p < .001. No effect of response time was found, F < 1.

Results are even more dramatic when individual data are observed. As can be seen in Figure 2, only a handful of subjects demonstrated declines in impulsivity scores while the majority improved greatly and in proportion to pre-treatment values. Improvement extended above and beyond the normal range for many individuals.

Figure 1. Pre- and post-treatment TOVA standard scores for all four dependent measures in 142 adults with attentional deficits and related disorders.

There is a systematic tendency toward improvement in attention, with the most significant improvements occurring where the pre-test scores are in most severe deficit (e.g., pre-treatment scores below 70). As can be seen, only a handful of subjects demonstrated marginal declines in impulsivity scores while the majority improved greatly and in proportion to pre-treatment values. Statistical analysis of this phenomenon supports this perception (p < .05). Those subjects with pre-treatment impulsivity scores greater than two standard deviations below the mean (i.e., scores of 70 and below) improved more than 27.2 points. Response variability improved 25.9 points and inattention scores improved by 40.4 points for those with pre-training scores of 70 or below.

In all, neurofeedback training produced clinically significant improvement (i.e., half a standard deviation increase or more on one or more measures), in 83 % of all subjects, a result superior to the 70% response rate of psychostimulants (Cantwell, 1994; Barkley, 1990).

Figure 2. Pre- and post-treatment TOVA impulsivity standard scores for 109 adults. Only adults with pre-treatment scores of 105 or below were included. Each line segment represents a single subject's change from pre-training to post-training scores. The data are sorted by pre-training score. Improvement is indicated when the line segment rises above the pre-training value.