Spectral Dynamics and Therapeutic Implications of the Theta/Alpha Crossover in Alpha-Theta Neurofeedback

Abstract

The theta-over-alpha frequency crossover seen in alpha-theta neurofeedback, considered an important factor in the treatment's success, has had little definitive research. This study examined 182 alpha-theta session graphs from 10 subject case files for interactions between frequency band activity and subject reports of imagery or biographical memories during crossovers, as well as treatment outcomes. Statistical analyses revealed significantly more reports of imagery/memories during crossover conditions having specific spectral, amplitude, and duration characteristics. Imagery reports were more likely to occur during crossover activity of 1 microvolt or more, lasting at least 3 minutes, and including 3.75µv of 15–20 Hz beta. This defined therapeutic crossover condition also was significantly related to better treatment outcome measures.