Positive and negative successive contrast effects following multiple shifts in reward magnitude under high drive and immediate reinforcement

Multiple shifts in reward amount were given to rats in a straight runway. Both positive and negative contrast effects were observed. A positive contrast effect was observed, however, only if the shift from small to large reward occurred while the subject was evidencing a negative contrast effect. Implications for current conceptions of reinforcement contrast are discussed.     

The use of think-aloud protocols to compare inferencing abilities in average and below-average readers

In this study, we examined whether think-aloud procedures would uncover differences in the kinds of inferences generated by average and below-average readers. Participants were 40 third-grade children who were divided into groups of average and below-average readers. All participants completed measures of nonverbal IQ, reading, language, and working memory, and a story comprehension task that consisted of two conditions: listen through and think aloud. The major findings in this study were that (a) average readers generated significantly more explanatory inferences than below-average readers, and (b) comprehension performance as measured by story recall was significantly better for both groups in the think-aloud condition than in the listen-through condition. The discussion addresses the implications of these findings.     

Survival responses to incest: Adolescents in crisis

Twenty-seven incest victims, aged 12-18, responded to their experiences with self-destructive behaviors such as substance abuse, suicide attempts, perfectionism, isolation, or depression in attempts to alleviate stress or assert some control over helplessness created by the incest. Therapy focused on the premise that such adolescent behaviors are logical and predictable survival responses rather than simply clues to sexual abuse. Treatment goals included establishing trust, helping the victim re-define his or her role in the incest, view destructive behaviors as predictable responses, and understand that present behaviors are a continuation of these past survival responses. Such self-awareness encourages the adolescent to better manage or discontinue now inappropriate behaviors.     

Conditioning of the nictitating membrane response of the rabbit (Oryctolagus cuniculus) as a function of length and degree of variation of intertrial interval

The study involved three experiments. The first, a parametric investigation of nictitating membrane conditioning with eight constant intertrial intervals (ITIs) between 5 and 120 sec, orthogonal to interstimulus intervals (ISIs) of 250 and 750 msec plus three temporal conditioning control groups, revealed that performance improved rapidly with increasing ITI but stabilized at relatively low ITI values. At 750-msec ISI, a decrement in performance was found at 60-sec ITI. Experiment II, using constant ITIs of 45–75 sec in 5-sec steps, at 750-msec ISI confirmed the trend toward a performance decrement around 60 sec, although the trend was weak and highly variable. Experiment III evaluated the differences in performance between constant and variable ITI, using three ITI values and three conditions of variation at each value. Findings were discussed in terms of differences in conditioning resulting from both length and degree of variation of ITI and some subtle effects which may emerge only when constant ITIs are used.     

The Strong African American Families Program: translating research into prevention programming

A randomized prevention trial contrasted families who took part in the Strong African American Families Program (SAAF), a preventive intervention for rural African American mothers and their 11-year-olds, with control families. SAAF is based on a contextual model positing that regulated, communicative parenting causes changes in factors protecting youths from early alcohol use and sexual activity. Parenting variables included involvement-vigilance, racial socialization, communication about sex, and clear expectations for alcohol use. Youth protective factors included negative attitudes about early alcohol use and sexual activity, negative images of drinking youths, resistance efficacy, a goal-directed future orientation, and acceptance of parental influence. Intervention-induced changes in parenting mediated the effect of intervention group influences on changes in protective factors over a 7-month period.