Aversive smoking therapies: A conditioning analysis of therapeutic effectiveness

Rapid smoking (RS) and a less aversive rapid-puffing (RP) treatment were compared on ability to enhance the impact of a behavioral-counseling (BC) procedure on psychophysiological, attitudinal and behavioral response to cigarettes. Data reveal that both aversive smoking treatments resulted in less smoking once treatment began, reduced smoking in post-treatment taste tests, and superior follow-up performance at 6 months and 1 yr. At 1 yr, RS S s achieved the highest number of days abstinent of any group. Regression analyses showed that Ss' confidence ratings of remaining abstinent were highly predictive of follow-up status, and that these ratings were related to number of cigarettes smoked during treatment and amount of smoking during post-treatment taste tests.     

The linear system theory's account of behavior maintained by variable-ratio schedules.

The mathematical theory of linear systems, which has been used successfully to describe behavior maintained by variable-interval schedules, is extended to describe behavior maintained by variable-ratio schedules. The result of the analysis is a pair of equations, one of which expresses response rate on a variable-ratio schedule as a function of the mean ratio requirement (n) that the schedule arranges. The other equation expresses response rate on a variable-ratio schedule as a function of reinforcement rate. Both equations accurately describe existing data from variable-ratio schedules. The theory accounts for two additional characteristics of behavior maintained by variable-ratio schedules; namely, the appearance of strained, two-valued (i.e., zero or very rapid) responding at large ns, and the abrupt cessation of responding at a boundary n. The theory also accounts for differences between behavior on variable-interval and variable-ratio schedules, including (a) the occurrence of strained responding on variable-ratio but not on variable-interval schedules, (b) the abrupt cessation of responding on occurrence of higher response rates on variable-ratio than on variable-interval schedules. Furthermore, given data from a series of variable-interval schedules and from a series of concurrent variable-ratio variable-interval schedules, the theory permits quantitative prediction of many properties of behavior on single-alternative variable-ratio schedules. The linear system theory's combined account of behavior on variable-interval and variable-ratio schedules is superior to existing versions of six other mathematical theories of variable-interval and variable-ratio responding.     

Confirmation of linear system theory prediction: Rate of change of Herrnstein's kappa as a function of response-force requirement

Four human subjects worked on all combinations of five variable-interval schedules and five reinforcer magnitudes (¢/reinforcer) in each of two phases of the experiment. In one phase the force requirement on the operandum was low (1 or 11 N) and in the other it was high (25 or 146 N). Estimates of Herrnstein's κ were obtained at each reinforcer magnitude. The results were: (1) response rate was more sensitive to changes in reinforcement rate at the high than at the low force requirement, (2) κ increased from the beginning to the end of the magnitude range for all subjects at both force requirements, (3) the reciprocal of κ was a linear function of the reciprocal of reinforcer magnitude for seven of the eight data sets, and (4) the rate of change of κ was greater at the high than at the low force requirement by an order of magnitude or more. The second and third findings confirm predictions made by linear system theory, and replicate the results of an earlier experiment (McDowell & Wood, 1984). The fourth finding confirms a further prediction of the theory and supports the theory's interpretation of conflicting data on the constancy of Herrnstein's κ.     

Reward value effects on timing in the peak procedure

Three experiments examined the effect of motivational variables on timing in the peak procedure. In Experiment 1, rats received a 60-s peak procedure that was coupled with long-term, between-phase changes in reinforcer magnitude. Increases in reinforcer magnitude produced a leftward shift in the peak that persisted for 20 sessions of training. In a final phase, the rats received lithium chloride-induced aversion prior to testing and a rightward shift in the peak was observed. Experiment 2 confirmed the rightward shift in the peak under lithium chloride devaluation and induced a comparable shift with satiety devaluation. The degree of rightward shift was neither additive nor multiplicative, suggesting that two processes may have contributed. Experiment 3 examined the effect of extinction on peak responding, revealing a decrease in response rate, but no evidence of any change in the timing of responding. The implications of the results for contemporary timing theories are discussed.     

Intolerance of Uncertainty and Eating Disorder Symptoms Over the Course of Intensive Treatment

There is a critical need to identify processes that may influence outcome in existing treatments for eating disorders (EDs). Intolerance of uncertainty (IU), which refers to excessive distress regarding uncertain situations, is a well-established feature of anxiety disorders. Emerging work suggests that IU decreases over the course of cognitive-behavioral treatments and may relate to better treatment outcomes. As some literature has suggested IU may functionally maintain ED symptoms, testing whether changes in IU over treatment relate to outcome may result in the identification of novel treatment targets. This study aimed to build upon past work documenting links between IU and ED symptoms by exploring changes in IU over treatment and links between early change in IU (1-month) and discharge symptoms. Participants (N = 274) receiving partial hospitalization treatment completed the Eating Pathology Symptoms Inventory and Intolerance of Uncertainty Scale at admission, 1-month post-admission, and discharge. Results suggested that IU significantly reduced from admission to discharge and that reductions in IU scores from admission to 1-month related to cognitive restraint, dietary restriction, and body image at discharge. However, this pattern did not hold for exercise, binge eating, or purging. Altogether, these results replicate past work supporting IU as a common feature across ED diagnoses and provide initial data suggesting that targeting IU early in treatment may enhance treatment outcomes.     

Developmental effects of an intervention for preterm infants of teenage mothers

Since preterm infants and infants born to teenage mothers are noted to be at risk for developmental delays, a group of infants who were both preterm and born to teenage mothers was provided a sensorimotor exercise intervention program for the first year of infancy. The development of these infants was compared to the development of preterm infants without intervention and term infants of teenage mothers as well as term and preterm infants of adult mothers to determine the degree to which developmental delays were prevented. The intervention infants showed more optimal growth, cognitive development, temperament and play behaviors during interactions with their mothers across the first year of development.