Behavioral contrast as a function of the temporal location of reinforcement

Pigeons were trained on a multiple variable-interval variable-interval schedule of reinforcement. One component was then changed to a variation of a fixed-interval schedule in which the same rate of reinforcement was obtained as previously but the location of the reinforcer was fixed within the component. The effects of different temporal locations were compared. An increase in response rate for the unchanged variable-interval component (behavioral contrast) occurred when the reinforcer was located in the middle or at the end of the FI component, but response suppression occurred when it was located at the beginning of the component. The pattern of results cannot be explained by any previous theories of contrast. The overall response rates, and the pattern of local rates within the components, were consistent with the hypothesis that the major determinant of the contrast effect was the transition to a lower reinforcement rate following the unchanged component.     

Sudden gains and outcome: a broader temporal analysis of cognitive therapy for depression

Individual Beck Depression Inventory (BDI) time courses of 38 clients receiving cognitive therapy (CT) and a modified form of CT were studied in order to investigate temporal changes during CT for depression. The primary aim was to determine if alternative methods of defining and computing gains occurring early in CT would alter the conclusions drawn in the current literature. Three types of gains were studied: sudden gains (previously studied sudden, substantial, and stable improvements in depression during 1 between-session interval after Session 2), first-session gains (occurring after first sessions), and pretreatment gains (occurring after pretreatment assessments). Positive outcomes were predicted by first-session gains and by sudden gains occurring in the first half of treatment, highlighting the importance of early change in CT for depression.     

Neuropsychologic functioning in children with autism: further evidence for disordered complex information-processing.

A wide range of abilities was assessed in 56 high-functioning children with autism and 56 age- and IQ-matched controls. Stepwise discriminant analyses produced good group discrimination for sensory-perceptual, motor, complex language, and complex memory domains but lower agreement for the reasoning domain than previously obtained for adults. Group discrimination did not occur for attention, simple language, simple memory, and visuospatial domains. Findings provide additional support for a complex information-processing model for autism, previously based on adult data, demonstrating a pattern across domains of selective impairments on measures with high demands for integration of information and sparing when demands were low. Children as compared to adults with autism exhibited more prominent sensory-perceptual symptoms and less pronounced reasoning deficits reflecting brain maturation.     

Ontogeny of the adrenal response to (+)-methamphetamine in neonatal rats: the effect of prior drug exposure

We examined the ontogeny of the corticosterone response to (+)-methamphetamine in neonatal rats. In experiment-1, animals were injected with 10 mg/kg of (+)-methamphetamine or saline and plasma corticosterone levels were examined in separate groups 30 or 105 min later on postnatal day (P) 1, 3, 5, 7, 9, 11, 13, 15, 17, or 19. The adrenal response to methamphetamine was best described by a U-shaped function with the nadir of corticosterone release occurring between P7 and P13. Experiment-2 was similar except that the effect of four consecutive days of exposure to (+)-methamphetamine (four times daily at 2 h intervals with 10 mg/kg) was assessed with a single final dose early on the fifth day (i.e. P1-5, 3-7, 5-9, 7-11, 9-13, 11-15, 13-17, 15-19). The 30 min corticosterone response after multiple methamphetamine doses was augmented compared to single exposures, with the exception of the two earliest dosing intervals ending on P5 and P7, where the responses were lower. In addition, at 105 min, the levels of corticosterone were attenuated relative to a single drug administration. With the exception of animals receiving methamphetamine from P15 to P19, thymus weights were unaffected. The data demonstrate that (+)-methamphetamine is a robust activator of corticosterone release in developing animals and this release is extensively modified by age and previous drug exposure.     

Moore’s Paradoxes and Conscious Belief*

For Moore, it is a paradox that although I would be absurd in asserting that (it is raining but I don’t believe it is) or that (it is raining but I believe it isn’t), such assertions might be true. But I would be also absurd in judging that the contents of such assertions are true. I argue for the strategy of explaining the absurdity of Moorean assertion in terms of conscious Moorean belief. Only in this way may the pathology of Moorean absurdity be adequately explained in terms of self-contradiction. David Rosenthal disagrees with this strategy. Ironically, his higher-order thought account has the resources to fulfil it. Indeed once modified and supplemented, it compares favourably with Brentano’s rival account of conscious belief. *This paper was written with the support of a grant from the SMU-Wharton Research center.     

Living the Image: A Quantitative Approach to Delineating Masculinities

Authors have repeatedly argued that a nearly exclusive focus on the dominant form of masculinity limits our knowledge of masculinity. Qualitative masculinities researchers have revealed multiple masculine forms, but quantitative researchers have not yet assessed them. This study adopted a social identity approach to examine endorsement of ten typically male images (Average Joe, Businessman, Family Man, Jock, Nerd, Player, Rebel, Sensitive New-Age Guy, Stud, Tough Guy) and their connections to gender norms and traits. Data from 340 male and 348 female adults revealed that identification with each image was related to a particular pattern of norm conformity and trait endorsement. Patterns varied by sex. Findings suggested that distinctions across images may be assessed quantitatively. Implications for quantitative research on masculinities were discussed.     

Self-instructions: Effects of cognitive level and active rehearsal

This research examined the effects of a self-instruction intervention on the relationship between cognitive level and conceptual tempo. Preoperational and concrete operational children received the Matching Familiar Figures Test prior to and after serving in either a no training control group, a content only control group, or a self-instruction group. Children in the content only control group received the same set of self-guiding strategy statements as those in the self-instruction group but without overt rehearsal of the statements. Cognitive level and conceptual tempo were strongly related; preoperational children tended to be classified as impulsive, concrete operational chidlren, as reflective. Although cognitive level predicted overall performance, with concrete operational children being more successful and more reflective than preoperational children, the influence of training was similar for both groups. On posttest, children in the self-instruction groups made more correct responses and were more reflective than children in the other two training groups.