Rewarding safety belt usage at an industrial setting: Tests of treatment generality and response maintenance

An incentive program to motivate seat belt use was implemented at a large munitions plant. Seat belt usage was assessed daily at an entrance/exit gate of the industrial complex when employees arrived for work in the morning and departed in the afternoon. During treatment incentive fliers, which prompted seat belt usage and gave belt wearers opportunities to win prizes, were distributed only in the afternoon. Seat belt wearing increased from baseline means of 20.4% and 17.3% during the morning and afternoon, respectively, to averages of 55.5% during afternoon departures and 31.1% during morning arrivals. During follow-up, mean belt use dropped almost to baseline levels. Categorizing vehicles according to driver sex and license plate number enabled a study of belt wearing practices of individuals, and revealed that the incentive program influenced some drivers to wear their seat belts during morning arrival when incentives were not distributed (i.e., treatment generalization) and during a follow-up period after the incentives were withdrawn (i.e., response maintenance).     

Stimulus probability and prediction outcome as determinants of choice reaction time: Some procedural considerations

Effects of stimulus probability and prediction outcome on two-choice reaction speed (CRS) were determined when a frequency imbalance was reversed half-way through 300 samples of a 70/30 stimulus distribution and when the same 70/30 distribution was sampled for 1200 trials. Prior to each presentation Ss made a prediction; following each presentation Ss identified the stimulus by pressing a right-hand or left-hand trigger. CRS was faster to correctly predicted stimuli, and faster to the more probable stimulus. Ss who were informed of the frequency imbalance reacted significantly faster than Ss who were not. Both practice and boredom effects were demonstrated by using the extended number of trials. CRS was faster during the second session of 300 trials than during the first; after two sessions, CRS was slower during the second half of two additional sessions.     

Prediction outcome probabilities as determinants of choice reaction time

In a two-stimulus two-response choice reaction time (RT) task in which Ss made stimulus predictions, the probability of a correct prediction was manipulated between Ss. The magnitude of the difference in RT to correctly and incorrectly predicted stimuli (i.e., the prediction outcome effect) was an increasing function of the probability of a correct prediction This finding was primarily due to a reliable decrease in RT to correctly predicted stimuli as the probability of a correct prediction increased, since RT to incorrectly predicted stimuli was not affected by prediction outcome probability. These results were interpreted as partially supporting a continuous expectancy notion which involves facilitory and inhibitory mechanisms winch are differentially influenced by the probability of a correct prediction.     

The effects of instructional set on physiological response to stressful imagery

Centrally mediated or cognitive variables have received considerable attention in clinical research. With the establishment of the effectiveness of such specific treatment techniques as systematic desensitization (Paul. 1969a. 1969b). a question arises as to the influence of cognitions on process and outcome variables in such learning based treatments (Lang. 1971). Research investigating the influence of demand characteristics and subject expectancies has demonstrated such centrally mediated variables can significantly influence overt, behavioral and self-report measures of fear, stress, or anxiety (cf. Borkovec. 1972: Marcia. Rubin and Efran. 1969; McGlynn. Maelia and Nawas. 1969: McGlynn. Reynolds and Linder. 1971: Oliveau. Agras. Leitenberg and Wright. 1969; Rappaport. 1972: Rosen. 1974).However. Borkovec (1972) and Rappaport (1972) failed to obtain expectancy effects on physiological measures of anxiety. Neither investigation provided for an independent assessment of subjects' actual expectancies, or belief in the instructions, as recommended by Davison and Wilson (1973). Borkovec administered clinical procedures over four sessions and varied the information communicated about the ‘purpose’ of the treatments (physiological versus therapeutic instructions). Differential rationales for differential expectancies of physiological reactivity were not provided. After each session, subjects reviewed the same false physiological records depicting reductions in fear responses. Although these changes were explained either physiologically or therapeutically. the fact that such reductions were emphasized should have attenuated differences between groups. Rappaport (1972) exposed subjects to a fearful stimulus and varied the suggestion and rationale for the pseudotreatment: no expectancy (stress research): therapeutic expectancy (fear reduction); and negative expectancy (fear increase). The lack of an independent assessment of the expectancy manipulation, as well as the exclusion of a specific therapeutic procedure, make it impossible to interpret the results in relation to expectancy effects on physiological fear responses during the administration of therapeutic procedures. There is other evidence, however, that suggestion and instructional set can significantly influence somatic and autonomic response systems (Barber. 1961. 1965; Sternbach. 1964. 1965).The primary purpose of this study was to evaluate the effects of instructional set on physiological responses to stressful imagery. This was an early step in a research program investigating the effects of instructional and informational variables on physiological responses of clinical interest. One half of the subjects received abbreviated live relaxation training (R) as described m a manual by Bernstein and Borkovec (1972) and based upon the original work of Jacobson (1938). The other half received an inert placebo pill and undertook a target detection task (P). The latter procedure was similar to that used by Paul (1966). Although both procedures had previously been shown to have relaxing effects, the P task was included as an additional control for any potential effects specific to the tension-release procedure of R. In order to evaluate the effects of instructional set, one half of each of the above two groups received instructions designed to lead to an expectancy of response inhibition to stressful imagery by the respective procedure (Decrease Stress Response. DSR). while the other half received instructions designed to lead to an expectancy of an increased response to stressful imagery by the respective procedure (Increase Stress Response. ISR). Each subject visualized three individually specified items that were the most frightening scenes imaginable prior to training and four times after training visualized the scene producing the largest response. Considerable effort was devoted to eliciting from each subject the most frightening items possible for her. and it was clear from subject comments that the items did elicit negative emotional responses.Since previous research (Barber. 1961. 1965; Sternbach. 1964. 1965) indicated that instructional set can influence physiological reactivity, it was hypothesized the DSR) subjects should exhibit a greater reduction in emotional response from pre- to posttraining than ISR subjects.     

Semantic memory verification of binary statements by children at three academic levels

Ninety-six binary statements were administered to 120 children randomly selected from three academic levels. The children were to respond TRUE or FALSE to each statement. Error count and latency for correct responses were used as measures of performance. The Constituent Comparison Model (Carpenter, P., & Just, M. A., Psychological Review, 1975, 82, 45–73), which postulates that verification latency will increase linearly with a linear increase in the number of hypothesized constituent comparisons, accounts quite well for the results obtained in this study. Furthermore, the results suggest an increasing efficiency in semantic memory verification across the three academic levels as reflected by a decrease in variability of performance, a decrease in the time required to read and encode sentences, and a decrease in the time required per constituent comparison.     

Shape constancy and a perceptual bias towards symmetry

In attempting to judge whether a briefly presented rotated figure was symmetrical (circle or square) or asymmetrical (ellipse or rectangle), a bias towards perceiving symmetry was evident. This bias appears to be perceptual rather than judgmental in origin in that it was affected neither by variations in the probability of occurrence of symmetrical figures nor by familiarization with the stimuli. A characterization of the stimulus similarity space based on the shape-slant invariance hypothesis is presented, and a model which incorporates both the similarity space and the symmetry bias is proposed. The model can account for our paradoxical finding that the more asymmetrical some projected images, the more likely they will be perceived as symmetrical. This model can also account for Massaro’s (1973, 1975) results on shape constancy. However, Massaro’s theory was not supported in that extension in depth did not account for increased difficulty of shape judgments.     

Promoting Safety Belt Use on a University Campus: An Integration of Commitment and Incentive Strategies1

Safety belt use on a university campus was substantially increased by offering faculty/ staff and students who signed and returned “buckle up” pledge cards the opportunity to win prizes donated by community merchants. The 28,000 pledge cards, committing signers to buckle up for an academic quarter, were distributed during the spring and fall of 1985. One portion of the card was designed to be hung from a vehicle's rearview mirror as a reminder of the pledge to buckle up. The other portion served as a sweepstakes ticket and was deposited in boxes located throughout the campus community. Each quarter, winners were drawn from the returned pledge cards during three consecutive weeks. Although a relatively small proportion of the pledge cards were signed and turned in (i.e., 11.9% during spring and 9.4% during fall), those who signed and returned a pledge card (n = 3117) increased their safety belt use significantly. Across both quarters, faculty/ staff pledgers went from a high pre-pledge belt use level of 32.2% to a post-pledge level of 46.7%, and students increased their belt use from a pre-pledge use of 21.4% to a post-pledge level of 36.6%.