THE AVERSIVE CONTROL OF EXCESSIVE ALCOHOL CONSUMPTION BY CHRONIC ALCOHOLICS IN THE LABORATORY SETTING1

The efficacy of several methods of aversive control of excessive alcoholic drinking was investigated in a semi-naturalistic setting that permitted objective measurement of the drinking behavior of chronic alcoholics. Studies 1A and 1B compared an escape-conditioning procedure with a control procedure in which aversive electrical shocks were administered before drinking. Neither procedure effectively decreased subjects' pretreatment, baseline alcoholic drinking behavior. In Study 2, aversive response-contingent shocks effectively suppressed alcoholic drinking, but drinking subsequently returned to its former levels after withdrawal of punishment. Self-administered shock appeared to be as effective as experimenter-administered punishment for controlling drinking, even when the punishment contingency was faded out over time. Study 3 replicated the suppressant effect of punishment, and demonstrated that contingent shock was significantly more effective than yoked, noncontingent shock. A direct comparison of self- versus experimenter-administered punishment suggested a possible slight advantage for the latter.     

ATTENTION TRAINING: THE USE OF OVERCORRECTION AVOIDANCE TO INCREASE THE EYE CONTACT OF AUTISTIC AND RETARDED CHILDREN

A crucial first step in teaching and training the retarded and autistic is to develop and maintain eye contact with the therapist. Functional movement training (an overcorrection procedure) plus edibles and praise were compared with edibles and praise alone as a method of developing eye contact in three such children. In both conditions, the child was given food and praise when eye contact occurred within 5 sec of the therapist's verbal prompt: “Look at me.” Functional movement training avoidance plus edibles and praise produced about 90% attention for the three children, while edibles and praise alone were less effective (eye contact never exceeded 55%). Functional movement training avoidance combined with edibles and praise appears to be an effective method of teaching eye contact and possibly other forms of instruction-following to behaviorally disordered children who are not always responsive to positive consequences.     

Increased reinforcement when timeout from avoidance includes access to a safe place

Three experiments investigated the reinforcing value of access to a safe place during timeout from an avoidance schedule. Rats were trained on conjoint schedules in which responding both postponed shock on a free-operant avoidance schedule and produced periods of timeout on fixed-ratio schedules. In some conditions, a shelf was inserted into the operant chamber during timeout, enabling subjects to get off the grid floor. The combination of timeout and shelf maintained substantially higher response rates than the baseline avoidance schedule with ratio requirements as high as 90 (Experiment I). Adding the shelf to timeouts in one component of multiple fixed-ratio schedules of timeout resulted in higher response rates in the component where the shelf was included (Experiment II). When timeouts with and without the shelf were arranged on concurrent schedules, the shelf-timeout combination was preferred, even when of shorter duration than timeout alone (Experiment III). In all three experiments, subjects climbed on the shelf, although all shocks were cancelled during timeout periods. The results could not be accounted for solely in terms of the reinforcing properties of changes in shock rates, but required an interpretation that ascribed conditioned reinforcing value to stimuli associated with such changes.     

Effects of magnitude of food reinforcement on free-operant response rates

In Experiment 1 rats were trained to press a lever on a variable-ratio schedule of food presentation and were then exposed to progressively increasing magnitudes of food reinforcement. Response running rates (rates exclusive of the postreinforcement pause) were found to increase as a function of increasing reinforcement magnitudes. The effect of reinforcement magnitude on response rates inclusive of the postreinforcement pause, however, was less pronounced. Increases in the magnitude of reinforcement were also found to increase the length of the postreinforcement pause. Rats in Experiment 2 were trained to respond on a chained differential-reinforcement-of-low-rate variable-ratio schedule, and were exposed to increasing magnitudes of reinforcement as in Experiment 1. Response running rates increased in the variable-ratio component but decreased in the other component of the schedule. The results are discussed with reference to incentive accounts of reinforcement and the action of reinforcement on the response units generated by the operative contingencies.     

Escape from serial stimuli leading to food

If the functional relations governing the strength of a conditioned reinforcer correspond to those obtained with other Pavlovian procedures (e.g., Kaplan, 1984), the termination of stimuli appearing early in the interval between successive food deliveries should be reinforcing. During initial training we presented four key colors, followed by food, in a recurrent sequence to each of 6 pigeons. This established a baseline level of autoshaped pecking. In later sessions, we terminated each of these colors or only the first color for a brief period following each peck, replacing the original color with a standard substitute to avoid darkening the key. Pecking decreased in the presence of the last color in the sequence but increased in the presence of the first. In accord with contemporary models of Pavlovian conditioning, these and other data suggest that the behavioral effects of stimuli in a chain may be better understood in terms of what each stimulus predicts, as measured by relative time to the terminal reinforcer, than in the exclusively positive terms of the traditional formulation (Skinner, 1938). The same model may also account for the initial pause under fixed-interval and fixed-ratio schedules of reinforcement.     

Affective responses to stretching exercises: Exploring the timing of assessments

Affective responses during exercise have been identified as a predictor of exercise adherence. However, research has been mostly limited to aerobic and resistance exercise. Considering that stretching activities are also an important component of physical fitness, this quasi-experimental study was designed to: 1) compare affective responses during and immediately after stretching exercises in apparently healthy adults, and 2) assess the consistency and repeatability of affect ratings obtained one week apart. For this purpose, we analyzed the Feeling Scale (FS) and Felt Arousal Scale (FAS) ratings using Time (during and after stretching) x Intensity (light, moderate, vigorous) x Stretched Muscle Group (quadriceps, hamstrings, glutes, latissimus dorsi, triceps) with repeated measures analysis of variance (ANCOVA) in 34 participants (21 males; aged 32.8 ± 8.6 years). The repeatability of FS and FAS ratings was assessed using two-way random-effects models, Intraclass Correlation Coefficients (ICC), and Bland-Altman plots. FS scores were higher following the stretching exercises, whereas FAS scores were lower, particularly in the vigorous intensity. In general, the inter-day repeatability for FS and FAS measurements was good across muscle groups. ICC tended to be higher at vigorous intensities. Ratings of core affect can be collected during static passive stretches using the FAS and FAS in ecologically valid settings. These results suggest that an adequate assessment of core affective responses to stretching activities should be performed during the exercises.     

Psychological defense mechanisms and electroencephalographic arousal

The aim of this study was to examine the relationship between psychological defense as measured by the Kragh tachistoscopic Defense Mechanisms Test (DMT), and general arousal properties of the individual as measured with electroencephalogram (EEG). The DMT assesses defense by presenting neutral and threatening pictures with very short exposure times. EEG characteristics were measured in the 8–12 Hz EEG frequency band during DMT testing. Twenty-one male subjects participated in the study. All were US Air Force personnel on active duty. Personnel with high defense mechanisms, defined in this connection as slow perception of the threat, tended to have higher cortical arousal after Stimulus exposure than the subjects with low defense mechanisms. The differences occurred mainly with new stimulus material without any threatening content. The differences in arousal response to novel stimuli may contribute to an understanding of the relationships between the Kragh DMT test and performance in life-threatening situations.     

Concurrent schedules: Quantifying the aversiveness of noise

Four hens worked under independent multiple concurrent variable-interval schedules with an overlaid aversive stimulus (sound of hens in a poultry shed at 100dBA) activated by the first peck on a key. The sound remained on until a response was made on the other key. The key that activated the sound in each component was varied over a series of conditions. When the sound was activated by the left (or right) key in one component, it was activated by the right (or left) key in the other component. Bias was examined under a range of different variable-interval schedules, and the applicability of the generalized matching law was examined. It was found that the hens' behavior was biased away from the sound independently of the schedule in effect and that this bias could be quantified using a modified version of the generalized matching law. Behavior during the changeover delays was not affected by the presence of the noise or by changes in reinforcement rate, even though the total response measures were. Insensitivity shown during the delay suggests that behavior after the changeover delay may be more appropriate as a measure of preference (or aversiveness) of stimuli than are overall behavior measures.     

Physiological arousal and attention in veterans with posttraumatic stress disorder

Psychophysiological reactivity has been well documented in WWII, Korean Conflict, and Vietnam veterans with posttraumatic stress disorder (PTSD). In addition, these individuals have demonstrated cognitive impairments within the domains of attention, concentration, new learning, and memory. However, there has been no research examining the impact of physiological arousal on attention in individuals with PTSD. This study documents the level of physiological arousal and associated disruption of attentional abilities in 28 Persian Gulf War veterans (18 without PTSD or other psychopathology and 10 with PTSD). This population represents a group of combat trauma victims who experienced a relatively acute onset of PTSD, thus providing a unique opportunity to compare prior psychophysiological and cognitive results with a group of veterans who manifested a recent onset of PTSD. Results indicated relatively comparable psychophysiological reactivity and arousal between Persian Gulf War veterans with PTSD and Persian Gulf War veterans without PTSD. Furthermore, attentional processes of veterans with PTSD were not more disrupted than in comparison soldiers. Results suggest that the intensity and chronicity of the disorder may impact physiological arousal and disruption of cognitive functioning. Following Persian Gulf War veterans with PTSD over time may reveal that psychophysiological arousal becomes more pronounced with chronicity, perhaps as memory networks become strengthened and/or neuroendocrine systems become increasingly disrupted.