Reliability issues in the penile assessment of incarcerants

Although there has been increased reliance upon the direct physiological measurement of penile tumescence in the assessment of sexual deviations, the reliability of these measures has never been empirically validated. This investigation evaluates the reliability of the rape index as a technique in differentiating rapists from nonrapists. Eighteen individuals incarcerated on non-sexual-related offenses were presented visual and audio stimuli depicting mutually consenting intercourse, rape, and aggression. These stimuli were presented under two instructional sets: (1) enchance arousal and (2) suppress arousal. Reliability indices for the rape index were computed among various conditions of modality presentation, instructional set, and test-retest conditions. The overall reliability of the rape index was found to be low. The implications of these results upon the assessment and classification of offenders is discussed.     

Retardation of autoshaping following pretraining with unpredictable food: Effects of changing the context between pretraining and testing

In Experiment 1, pigeons exposed to US ONLY pretraining were observed to be retarded in the acquisition of autoshaping relative to naive controls; however, gross changes in contextual stimuli between pretraining and testing alleviated the retardation effect. In Experiment 2, groups of pigeons exposed to CS ONLY, US ONLY, or random CS-US presentations (TRC) were tested for the acquisition of autoshaping. The US ONLY and TRC groups were retarded relative to naive controls. The context change manipulation eliminated the US ONLY retardation effect and attenuated, but did not eliminate, the TRC retardation effect. Context blocking accounts for the US ONLY effect and contributes to the TRC effect; however, context-independent retardation following TRC pretraining suggests the operation of the learned irrelevance cognition.     

Feature distribution and background knowledge in category learning

Three experiments examined the interactions of category structure and prior knowledge in category learning.Experiment 1 examined the distribution of atypical or 'crossover' features in category learning. In real categories, crossover features may be unevenly distributed found primarily in very unusual examples of a category (like whales or ostriches). In contrast, in many psychology experiments, each item has exactly one crossover feature. Even versus uneven distribution of crossover features did not affect category learning when the features were neutral. However, when the features were connected by prior knowledge, it was much harder for subjects to learn the structure with the uneven distribution of crossover features. Experiments 2 and 3 found similar results with a slightly less uneven condition. We conclude that learning is a function of the interaction of category structure and prior knowledge rather than either one alone. Furthermore, knowledge benefits learning even when the category contains contradictions of the knowledge, so long as the contradictions are not very salient.