The Effects of Hippocampal and Area Parahippocampalis Lesions in Pigeons: I. Delayed Matching to Sample

Four experiments were conducted to determine the effects of bilateral damage to the hippocampus and area parahippocampalis (Hp-APH) on visual memory in pigeons using the delayed matching-to-sample (DMS) procedure. In Experiment 1, we generated visual retention gradients with delays of 0, 1.5, 3, 6, and 12 sec both preoperatively and postoperatively in three pigeons with considerable preoperative visual DMS experience. Bilateral Hp-APH lesions had no effect whatsoever on visual retention. In Experiment 2, we examined the effects of Hp-APH lesions on both the acquisition of a visual DMS task with a 0-sec delay, and the subsequent retention performance with delays of 0, 3, 6, 12, and 24 sec. There was no difference between unoperated control pigeons and Hp-APH pigeons either in terms of the number of sessions required to learn the visual DMS task or in terms of their subsequent visual retention performance levels. In Experiments 3 and 4, we examined whether Hp-APH pigeons might be more sensitive than control pigeons to the effects of proactive interference (by reducing the duration of the intertrial interval) and retroactive interference (by introducing delay-interval illumination). Although reducing the duration of the intertrial interval and increasing the level of delay-interval illumination both resulted in lower performance levels on the visual DMS task, there was no indication that the Hp-APH pigeons were any more affected by the changes in interference levels than were unoperated control pigeons. These findings support the view that the Hp-APH in pigeons plays little role in the processing and retention of purely visual information.     

Experimental components analysis of brief theory-based HIV/AIDS risk-reduction counseling for sexually transmitted infection patients.

An experimental components analysis of brief HIV risk-reduction counseling based on the information-motivation-behavioral skills (IMB) model was conducted with 432 men and 193 women receiving sexually transmitted infection (STI) clinic services. Following baseline assessments, participants were randomly assigned to 1 of 4 90-min risk-reduction counseling sessions that deconstructed the IMB model within a full factorial design. Participants were followed for 9 months, with STI diagnoses monitored over 12 months. Men who received the full IMB session evidenced relatively greater use of risk-reduction behavioral skills and relatively lower rates of unprotected intercourse over 6-months follow-up and had fewer new STIs. For women, however, the motivational counseling demonstrated the most positive outcomes. Results suggest that brief single-exposure HIV prevention counseling can reduce HIV transmission risks.     

Adolescent males' sexual behavior and contraceptive use: implications for male responsibility

A recent US survey of single 17-21 year old men, indicated that 17.1% used a condom at 1st intercourse and 15.5% used a condom at the most recent intercourse. Withdrawal is also used: 10.0% and 7.4% respectively. Condom use was correlated with being older at 1st intercourse, having a higher educational level, closer association to partner, and sense of male contraceptive responsibility. The data used for this analysis was taken from a sub-sample of 624 sexually active males in 1979. The mean age at 1st intercourse was 14.8 years and mean age at most recent was 18.9 years. The pill was also used at 1st intercourse (8.8%) and a total of 43.5% used some method of contraception. In the most recent intercourse cases, 64.7% used some method of birth control and the pill was used 26.5% , condom 15.5%, and withdrawal 7.4%. Conclusions from this data indicate that male methods are important in teen contraception. Condom use at 1st and most recent intercourse was related to both positive and negative characteristics. It appears that males show some contraceptive responsibility initially but later give the responsibility to females. The declining use of condoms indicates it to be a transitional form of birth control. Programs should promote continued use of condoms since use of the pill is low and unwanted pregnancy risk is high. Communication on contraception should be encouraged, so both partners are aware if neither one is contracepting. With the acquired immunodeficiency syndrome epidemic, condom use takes on a whole new context in relation to the decline in use by adolescents.     

The effects of bonus contingencies in a classwide token program on math accuracy with middle-school students with behavioral disorders

The effects of bonus points contingent on 80% accuracy in math with four middle-school special education students with behavior disorders were examined. A multiple-baseline design across students was used to evaluate the effects of bonus points. The overall results indicated that higher accuracy was found for math assignments during the bonus points condition than during baseline. This overall outcome was replicated for each subject in the study. The benefits of implementing a bonus contingency within an ongoing classroom token economy with middle-school students with behavior disorders are discussed. © 1998 John Wiley & Sons, Ltd.