Studies on the operant conditioning of central nervous system activity have produced results interpreted as demonstrating that responses, certain properties of responses, or response-produced stimuli can function as discriminative stimuli. It is assumed that the feedback stimulus in biofeedback makes the subject aware of the internal response and that by becoming aware of the response, the subject can acquire voluntary control over it. In this context, awareness is operationally defined as the ability to use the response as a discriminative stimulus. Since direct evidence for the assumed relationship between control and discrimination is lacking, an attempt was made to test the hypothesis that discrimination of a response automatically leads to control over that response. The discriminative stimuli were the presence and absence of occipital alpha electroencephalograph (EEG) activity. Data from two experiments are reported. The first study, employing naive subjects, was designed to answer the following questions: (a) Since pilot data indicated that subjects seemed to match their responses to the more probable type of trial, would increases in the probability of a correct response result when the probabilities of alpha and nonalpha trials were held near .50? (b) If correct responding does increase, would performance of these subjects in an alpha feedback task be enhanced relative to that of subjects not previously given discrimination training? and (c) If subjects could not learn the discrimination task, would feedback training enhance their performance in a subsequent discrimination task? Results from this study indicate that holding the probabilities of alpha and nonalpha discrimination trials near .50 results in an absence of learning curves, but leaves open the possibility that sophisticated subjects are capable of discriminating alpha and nonalpha activity. The second study deals with two questions: (a) Can sophisticated subjects learn to discriminate occipital alpha activity from nonalpha activity? and (b) Does the procedure of providing subjects with salient stimuli, contingent on the presence and absence of alpha activity, establish stimulus control of the presence and absence of alpha activity? Results indicate that it is not possible to conclude that subjects can learn to discriminate alpha and nonalpha activity. However, learning to increase percent-time nonalpha or decrease percent-time alpha with respect to baseline levels by means of EEG-contingent stimulation provides subjects with the ability to suppress percent-time alpha in the absence of feedback. Information gained in both studies through subject interviews indicates that subjects most often acquired their control of alpha activity during feedback by a specific strategy and then used the strategy during the stimulus-control tests.

This study tested the hypothesis that functional morbidity in benign chest pain can be modified independently of symptoms through interdisciplinary medical and cognitive-behavioral intervention. Analyses used data collected in a sixteen-week trial of interdisciplinary treatment for disability in benign chest pain. One hundred four chest pain patients having normal coronary arteriograms (NCA) (n = 14) or mitral valve prolapse (MVP) with no other known cardiac or arterial disease (n = 90) were assigned to individual treatment, group treatment, self-monitoring attention control, or a wait-list control group. Results indicate that interdisciplinary intervention, in group or individualized format, was successful for improving short-term and long-term (follow-up range = six to sixteen months) functional status, in both MVP and NCA patients. Correlation analysis indicated that functional improvements were not dependent on reductions in the frequency of symptoms. In fact, significant reductions in disability were obtained in those treated patients (13 of 43) who reported no reduction, or an actual increase, in the frequency of chest symptoms. These data indicate that disability in benign chest pain may be modified independently of symptoms by an integration of medical and cognitive-behavioral strategies.

Thirty-four patients having chronic idiopathic headaches participated in a long-term study comparing autogenic relaxation training alone (REL) with combinations of relaxation and electromyographic biofeedback (REL + EMG) or relaxation and temperature biofeedback (REL + TEMP). Assignment to treatment conditions was balanced on demographics and clinical characteristics, as well as headache classification according to muscle contraction or vascular headache symptomatology. The results indicate that REL + TEMP produced no additional improvements over REL following the 8-week treatment program, or at 6-month, or 12-month follow-up. However, REL + EMG produced significantly greater reductions in headache activity measures than the REL and REL + TEMP conditions at all post-treatment time points. Headache activity continued to improve over the follow-up period independent of treatment condition. These data indicate that EMG biofeedback augments long-term clinical improvements in headache patients who undergo autogenic relaxation training.

Operant conditioning of the sensorimotor rhythm of the human electroencephalogram with time-outs contingent on epileptiform activity reduces epileptic seizure rates in patients whose seizures are not well controlled by medication. A comparison of this procedure with time-out training alone demonstrates that operant conditioning of the sensorimotor rhythm is neither necessary nor sufficient for seizure reduction.

A critical assumption in the rationale for the clinical application of voluntary control over central nervous system (CNS) activity is that there exists a direct relationship between specific CNS activities and specific subjective mood states. The experiment reported here was based on the idea that a joint manipulation of both cognitive and physiological (i.e., alpha electroencephalographic [EEG]) variables would provide information required for an explication of the processes involved in subjective mood change. Three main variables were considered in the present experiment. First, the instructions were designed to induce a "set" or expectations for either positive or negative changes in subjective mood. Second, the type of feedback (alpha or not alpha) was varied. Those in the not-alpha feedback condition received feedback contingent on the absence of alpha activity, whereas those in the alpha feedback condition received feedback contingent on the presence of alpha activity. Third, an estimate of each individual's baseline alpha density was obtained, and on this basis subjects were classified as high-baseline or low-baseline subjects. Baseline alpha density, alpha density during training, and subjective mood were all considered as continuous variables. The results of the present study indicate that biofeedback of the cortical alpha rhythm is neither a sufficient nor a necessary condition for changes in subjective mood. In addition, the type of instructions designed to set subjects for positive or negative alterations in subjective states is predictive of changes in subjective state reported during alpha biofeedback training as well as of success at controlling and changing EEG during feedback training. The data presented here permit a direct examination of the actual relationship of EEG changes to changes in subjective mood state. Similar shifts in subjective mood state can be obtained with either increases or decreases in alpha activity. Further, both positive and negative subjective experiences can be associated with increases in alpha activity.