Operant conditioning of EEG rhythms and ritalin in the treatment of hyperkinesis

Enhanced voluntary motor inhibition regularly accompanies conditioned increases in the sensorimotor rhythm (SMR), a 12--14-Hz Rolandic EEG rhythm in cats.A similar rhythm, presumably SMR, has also been identified in the human EEG. The clinical effectiveness of SMR operant conditioning has been claimed for epilepsy, insomnia, and hyperkinesis concurrent with seizure disorders. The present report attempts to follow up and replicate preliminary findings that suggested the technique's successful application to hyperkinesis uncomplicated by a history of epilepsy. SMR was defined as 12--14-Hz EEG activity in the absence of high-voltage slow-wave activity between 4 and 7 Hz. Anticipated treatment effects were indexed by systematic behavioral assessments of undirected motor activity and short attention span in the classroom. EEG and behavioral indices were monitored in four hyperkinetic children under the following six conditions: (1) No Drug, (2) Drug Only, (3) Drug and SMR Training I, (4) Drug and SMR Reversal Training, (5) Drug and SMR Training II, (6) No Drug and SMR Training. All hyperkinetic subjects were maintained on a constant drug regimen throughout the phases employing chemotherapy. Contingent increases and decreases in SMR occurred in three of four training subjects and were associated with similar changes in classroom assessments of motor inactivity. Combining medication and SMR training resulted in substantial improvements that exceeded the effects of drugs alone and were sustained with SMR training after medication was withdrawn. In contrast, these physiological and behavioral changes were absent in one highly distractible subject who failed to acquire the SMR task. Finally, pretraining levels of SMR accurately reflected both the seve-ity of original motor deficits and the susceptibility of hyperkinetic subjects to both treatments. Although the procedure clearly reduced hyperkinetic behavior, a salient, specific therapeutic factor could not be identified due to the dual EEG contingency imposed combined with associated changes in EMG. Despite these and other qualifying factors, the findings suggested the prognostic and diagnostic value of the SMR in the disorder when overactivity rather than distractibility is the predominant behavioral deficit.     

Operant conditioning in invertebrates

Learning to anticipate future events on the basis of past experience with the consequences of one's own behavior (operant conditioning) is a simple form of learning that humans share with most other animals, including invertebrates. Three model organisms have recently made significant contributions towards a mechanistic model of operant conditioning, because of their special technical advantages. Research using the fruit fly Drosophila melanogaster implicated the ignorant gene in operant conditioning in the heat-box, research on the sea slug Aplysia californica contributed a cellular mechanism of behavior selection at a convergence point of operant behavior and reward, and research on the pond snail Lymnaea stagnalis elucidated the role of a behavior-initiating neuron in operant conditioning. These insights demonstrate the usefulness of a variety of invertebrate model systems to complement and stimulate research in vertebrates.     

Operant conditioning in the ant Myrmica sabuleti

Operant conditioning could be obtained in the ant Myrmica sabuleti by presenting to the workers, during a six-day period, an apparatus containing either sugared water or meat as a reward. The conditioning obtained using sugared water as a reward was short lasting. A reconditioning was more persistent and lasted four hours. The ants' response was very precise, since they exhibited it only in front of an apparatus identical to that used during the training phase. Operant conditioning obtained using meat as a reward was more pronounced than that obtained by using sugared water, probably because meat is more valuable as a reward than sugar for the species studied, which is essentially a carnivorous one. Such a conditioning was rather persistent. Indeed, a first operant conditioning obtained by using meat as a reward could still be detected after seven hours, and a reconditioning was still significant after eight hours. One day after this eight-hour period without rewarding the ants, the response was higher again and a further day later, it was still significant. Since the operant conditioning is easy to perform and quantify and since the ants' response is very precise, such a conditioning can be used for further studying M. sabuleti workers' visual perception.     

Operant conditioning of scratching in lemurs

An adult femaleLemur catta and an adult femaleEulemur fulvus were given edible rewards for scratching. Both subjects learned to scratch in order to obtain the rewards, showed diminished rates of scratching during periods of extinction, and learned to scratch preferentially with one foot when required. TheLemur catta subject was more responsive to the changing experimental conditions than theEulemur fulvus. The conditionability of scratching in primates does not appear to be directly related to the widespread occurrence of scratching in simian social contexts.     

Operant conditioning of skin resistance tonic levels

The purpose of the current investigation was to determine whether increases and decreases in skin resistance tonic level could be controlled by individuals given discrete visual feedback of such activity. Thirty-six male undergraduate students served as subjects. They were assigned randomly in equal numbers to four groups; two of the groups received accurate feedback of skin resistance level changes and two received inaccurate feedback. The two accurate-feedback groups differed with respect to the order in which increases and decreases in skin resistance level were reinforced. Each noncontingent group was matched with one of the contingent groups in terms of reinforcement density. The results indicated that accurate feedback produced skin resistance level changes consistent with the type of reinforcement employed. However, operant control was not clearly sustained subsequent to a reversal in the type of tonic level change reinforced. Some problems related to the clinical application of skin resistance level training are discussed.Portions of this paper were presented at the meeting of the Midwestern Psychological Association, Chicago, 1973.     

Operant conditioning of skin resistance tonic levels

The purpose of the current investigation was to determine whether increases and decreases in skin resistance tonic level could be controlled by individuals given discrete visual feedback of such activity. Thirty-six male undergraduate students served as subjects. They were assigned randomly in equal numbers to four groups; two of the groups received accurate feedback of skin resistance level changes and two received inaccurate feedback. The two accurate-feedback groups differed with respect to the order in which increases and decreases in skin resistance level were reinforced. Each noncontingent group was matched with one of the contingent groups in terms of reinforcement density. The results indicated that accurate feedback produced skin resistance level changes consistent with the type of reinforcement employed. However, operant control was not clearly sustained subsequent to a reversal in the type of tonic level change reinforced. Some problems related to the clinical application of skin resistance level training are discussed.     

Ultradian rhythms in the EEG and task performance

The purpose of this work was to investigate the presence of ultradian rhythms in: 1. levels of electroencephalographic activation; 2. interhemispheric correlation and 3. the performance of two cognitive tasks, and the correlation between these variables. Eight volunteers, aged 20 to 30, participated in the experiment. Two sessions were carried out: one from 0800 to 1400 on one day and the other from 1400 to 2000 another day. Samples of EEG activity were taken every 15 min at rest with eyes open in left and right temporal, central, parietal and occipital derivations referred to the ipsilateral earlobe the performance on two tasks, one logico-analytical (left hemisphere functions) and one spatial test (right hemisphere functions) was assessed. As control, body and environmental temperature were recorded. To test for the presence of ultradian rhythms, the data were subjected to a Fourier analysis. Different EEG variables showed rhythmicity throughout the sessions, principally with slow oscillation periods (3 and 6h); ultradian rhythms with 3h periods were also found in body temperature, while task performance showed no significant rhythmic patterns during sessions. Finally, no significant correlations were found between physiological variables evaluated and task performance.     

Operant conditioning of brain steady potential shifts in man

Steady potential shifts (SPS) recorded from the scalp were conditioned operantly by visual and acoustical feedback. Three groups of seven subjects were each tested with a different response-reinforcement contingency: positive reinforcement for a positive SPS after a cue stimulus, positive reinforcement for a negative SPS after a cue stimulus, and noncontingent reinforcement. The steady potential shifts learned under these three conditions differed significantly. Negative shifts were associated with subjective feelings of activation, positive shifts with inactivation. Cortical genesis and possible artifacts are discussed.This research was supported by a grant from theFond zur Förderung der wissenschaftlichen Forschung.     

Operant conditioning of cortical steady potential responses in rats

This study was conducted to determine if amplitudes of rat corticol steady potential (SP) response to an auditory stimulus could be altered by operant conditioning procedures using food reinforcement. The negative SP responses to the 5-sec tone alone diminished with repeated presentation of the stimulus. When food reinforcement was given immediately following the tone, SP response amplitudes increased and stabilized after 4–5 sessions. Thereafter, the animals were required to increase or decrease the amplitudes of response in order to obtain reinforcement. Two of three rats required to increase amplitudes were successful and three of four rats required to decrease amplitudes were successful. It is concluded that changes in cortical SP responses can be operantly conditioned.     

Operant conditioning of small birds for acoustic discrimination

Standard operant conditioning techniques have been successfully applied to the problem of call discrimination in small birds. Budgerigars (Melopsittacus undulatus) and canaries (Serinus canarius) were trained with a GO/NOGO procedure using positive reinforcement to discriminate between both conspecific contact calls and contact calls of the other species. Budgerigars showed equal facility at each task. By contrast, canaries learned the task involving conspecific contact calls but failed, as a group, to discriminate between budgerigar contact calls. These results show that conditioning techniques can be used to study perceptual learning of species typical calls in small birds.     

Operant conditioning and behavioral analyses using a minicomputer.

An operant conditioning and data analysis software system was developed for use on a PDP-12A minicomputer. The operant software functions in quasi time-sharing fashion to control and acquire data from any peripheral device that operates in the binary mode. In addition to independently running different experiments in near simultaneous fashion, the program also provides information on the current status of each experiment using a cathode ray-tube display. Response data from each experimental subject is stored on magnetic tape and analyzed, off-line, by the data analysis portion of the software system. A discussion of the operation of this system is given for one possible application: visual discrimination training.     

Operant control of EEG and event-related and slow brain potentials

Research on operant control of brain potentials is reviewed. From single-unit firing and spontaneous EEG activity to event-related potentials such as sensory and pain evoked potentials, and slow potential shifts, most of the aspects of electrical brain activity have been investigated. Results produced by conditioning of spontaneous EEG oscillations (alpha and theta) dampened the early enthusiasm: e.g., no increase above baseline levels could be achieved and no reliable behavioral effects became manifest. Evidence accumulates, however, that operant conditioning of the sensorimotor rhythm (12–15 Hz) may lead to successful self-regulation and that epileptic patients may profit from the training. First steps in the conditioning of brainstem, as well as pain evoked potentials suggest that self-regulation of EPs can be achieved by adequate biofeedback procedures. If some of the observed behavioral effects prove to be stable, the therapeutic usefulness seems to be within reach. A comparable progress has been achieved for the operant control of slow potentials (DC-shifts across seconds). Biofeedback procedures have been used successfully as a scientific tool to achieve systematic variations on a psychological level and to record psychological covariations. This method may provide insights into the behavioral meaning of electrical brain activity.     

Operant conditioning of brain steady potential shifts in man.

Steady potential shifts (SPS) recorded from the scalp were conditioned operantly by visual and acoustical feedback. Three groups of seven subjects were each tested with a different response-reinforcement contingency: positive reinforcement for a positive SPS after a cue stimulus, positive reinforcement for a negative SPS after a cue stimulus, and noncontingent reinforcement. The steady potential shifts learned under these three conditions differed significantly. Negative shifts were associated with subjective feelings of activation, positive shifts with inactivation. Cortical genesis and possible artifacts are discussed.     

Differential shaping of EEG theta rhythms

Heart rate, EEG, frontal EMG, and forearm EMG were recorded in 20 subjects for 3 baseline, 8 feedback, and 2 postbaseline sessions in order to compare two biofeedback methods of teaching subjects to increase theta EEG activity. Subjects were divided into high- and low-EMG groups. Five high-EMG subjects, and 5 low-EMG subjects then received 8 sessions of strictly theta feedback. The remaining 10 subjects, 5 from the high-EMG group, and 5 from the low-EMG group, received a “graduated” training which involved shaping the target response. This procedure consisted of 4 initial sessions of EMG feedback, followed by a second phase consisting of 4 sessions of theta feedback. Results showed a clear relationship between subjects' baseline frontal EMG levels and the effect of the training methods. Although subjects with high-EMG baseline increased their theta output only with the two-phase training, subjects with low-EMG baseline levels performed better when given theta feedback only. This result shows not only that amounts of theta can be reliably increased, but that training techniques should be adapted to the physiological characteristics of the individual—in this case, baseline levels of frontal EMG levels.     

Changes in EEG rhythms during verbal and visual-image thinking

General and local characteristics of EEG activation were studied in frontal, central, temporal and occipital areas of the left and right cerebral hemispheres in 20 adult subjects during execution of various mental tasks. The analysis of the changes of five main EEG rhythms (delta, theta, alpha, beta-1 and beta-2) showed that EEG power decrease in alpha- and beta-frequency ranges is a reliable and sensitive index of brain activation at thinking. On this basis EEG activation mosaics are described at carrying out of each task and its systemic changes at transition from one type of task to another one, depending on their psychological structure--modality and complexity.