No abstract

The relationship between discrimination and control of physiological states is largely unexplored, although it is often suggested that this relationship is important for the mechanism of action of biofeedback. This pilot study examined 6 participants given seven sessions of alpha discrimination training combined with standard neurofeedback "control" training. Four subjects achieved five criterion (binomial p < .05) sessions in the discrimination task. The discrimination task performances correlated significantly with performance in the amplitude control task. Evidence that some subjects can use the intertrial interval (ITI) to predict the correct responses in the discrimination task led to an examination of how ITIs were distributed with respect to success (correct or incorrect) and type of trial (same or different from previous) in these and 40 additional subjects from archival data (Frederick, 2012). This analysis found that some information about the correct responses was conveyed by the ITI, but participants made relatively little use of this information. However, the criterion discrimination sessions showed dramatic changes in the distribution of ITIs in the present (but not the archival) study, suggesting that participants were controlling their electroencephalogram (EEG) during these sessions. These findings provide preliminary evidence of generalization of skills between these two tasks.

EEG state discrimination studies may contribute to understanding the role of awareness in physiological selfregulation, but many individuals learn the existing paradigm very slowly. In this study, a self-prompted discrimination paradigm, in which subjects decide when to respond based upon their subjective state, was examined for the rate of learning and its effects on the ability to control EEG alpha. Twenty-nine participants received up to three 40-min sessions in which discrimination training was alternated with training to control alpha in four 10-min sets, compared to 22 participants who received control training only. Discrimination training appeared to facilitate the ability to control alpha amplitude, but only in the first session. The rate of learning of the discrimination paradigm was markedly greater than seen in previous studies. Comparing the time series of postresponse alpha amplitudes suggested that the lowest scoring sessions involved a behavioral inertia, or difficulty switching states, particularly when a higher alpha state was required. However, extreme amplitudes were discriminated better than moderate ones and discrimination task performances significantly exceeded the percent time that alpha amplitude was in the correct state. These two observations suggest that EEG discrimination involves awareness of, and not just manipulation of, one's EEG state.