Structural complexity as a determinant of serial pattern learning

A new methodology extends the study of serial pattern learning to nonhuman organisms by constructing patterns using elements that are both familiar and motivationally meaningful to animals. Two experiments examine the ability of rats to anticipate various quantities of food as measured by running times in a runway when the quantities occur in a serial order. In Experiment 1, a serial monotonic pattern (14-7-3-1-0 food pellets) produced more rapid learning and more accurate anticipation of the various quantities (“tracking”) than a serial nonmonotonic pattern (14-1-3-7-0 food pellets), particularly with respect to the final 0-pellet element. In Experiment 2, the same monotonic pattern generated faster learning and more accurate anticipation of pattern elements than a weakly monotonic pattern (14-5-5-1-0 pellets). Associative explanations including simple excitatory or inhibitory effects, temporal anticipation, reinforcement contrast, and the number and discriminability of pairwise associations are not adequate to account for the data. Rather, the formally defined structural complexity of each pattern adequately predicts its relative difficulty.     

Stress and subjective life expectancy: Cross-sectional and longitudinal associations in early adolescence

Using data from a longitudinal study, the present study employed a latent class mover-stayer analytical strategy to examine both the cross-sectional and longitudinal (+33 months) relationship between membership of stress classes, and subjective life expectancy. Participants were from 21 High schools in Scotland and Northern Ireland. Data were collected in the first year of High school (mean age = 12.5 years), and at +33 months (fourth year, or school year 11). Sample 1 consisted of 1171 adolescents (40.82% females, 2.56% unreported) in Northern Ireland. Sample 2 consisted of 1059 adolescents (52.79% females, 1.32% unreported) in Scotland. Adolescents with the lowest levels of stress projected the highest subjective life expectancy scores. Longitudinal analyses were jumbled and not in keeping with cross-sectional results. More research may be needed on the trajectory of subjective life expectancy over time before it can be depended upon as a reliable outcome variable in adolescent development.     

Age influences domestic dog cognitive performance independent of average breed lifespan

Animal Cognition - Across mammals, increased body size is positively associated with lifespan. However, within species, this relationship is inverted. This is well illustrated in dogs (Canis...     

The violent matrix: a study of structural,interpersonal, and intrapersonal violence among a sample of poor women

One goal of this paper is to present an integrated tripartite model of violence, with a focus on structural violence within an oppression paradigm. Using qualitative and quantitative data from 27 women (70% African American and 30% European American) who participated in a national substance abuse treatment demonstration program, we describe a model of violence in which structural violence is presented within a transactional relationship with interpersonal, and intrapersonal violence. We suggest that the effects of structural, interpersonal, and intrapersonal violence are magnified when race and poverty are considered. The second goal of the paper is to present a preliminary test of the new model of violence. Results indicated that different levels and types of violence are interrelated. Implications of these findings for empowering solutions are suggested.