The effects of stimulus movement and attention on peripheral stimulus localization by 8- to 26-week-old infants

This study examined the effect of stimulus movement on localization probability and latency during attention and inattention. Forty infants, 10 each at 8, 14, 20, and 26 weeks of age were presented with a central stimulus. Then, a peripheral stimulus was presented (static or dynamic checkerboard). Stimulus movement did not affect localization probability. Infants localized the dynamic peripheral stimulus more quickly than the static peripheral stimulus when there was no focal stimulus. Focal stimulus attention attenuated this difference in localization latency between static and dynamic stimuli. Signal detection analysis showed that sensitivity to the peripheral stimulus increased over this age range along with a decrease in the bias against responding. The effects of attention were on response bias rather than stimulus sensitivity. These results imply attention affected the localization response to the peripheral stimulus but did not affect the sensitivity of the sensory and perceptual pathways to peripheral stimuli.     

The corridor illusion

Contrary to general belief, the classical corridor illusion is not due solely to the perspective and contextual cues provided by the corridor. Additional factors that are equally important are the inherent spatial anisotropies of the visual system and fixation tendencies.     

A comparison of two online cognitive‐behavioural interventions for symptoms of depression in a student population: The role of therapist responsiveness

Objectives: The study aimed to compare the efficacy of eight weekly sessions of a self‐administered online CBT treatment (cCBT; n=51) to a therapist‐assisted email CBT treatment (eCBT; n=50) in University students. Design: The design was a randomised parallel group trial. The study randomised participants with symptoms of depression to one of two available treatments. Method: Participants were offered eight weekly sessions of either cCBT or eCBT. Participants completed the Beck Depression Inventory‐II (BDI‐II) and the Clinical Outcomes in Routine Evaluation – Outcome Measure (CORE‐OM) at pre‐and post‐treatment, at weeks 16 and 32 follow‐up. The Working Alliance Inventory‐Short Form (WAI‐SR) was completed at weeks 2, 4, and 6. Results: For both groups, pre‐post within group effect sizes reported were large for the BDI‐II and the CORE‐OM and these were maintained at follow‐up. Perceptions of working alliance were similar in each group, but Bond was significantly stronger for the eCBT condition. WAI scores correlated more positively with the outcome on BDI‐II for those in the eCBT condition than the cCBT condition, but not significantly. Conclusion: There were no significant differences between the two online treatments, both reduced depressive symptoms and improved general functioning. Similarly, at post‐treatment and follow‐up, clinical improvement and recovery was demonstrated for both groups equally. The study demonstrates the possibility for cCBT in a university setting that may contribute to addressing the shortcomings in meeting increasing demands that mental health services presently face.     

Stimulus control and delayed reinforcement

Pigeons were tested for generalization along the line-orientation dimension, after being trained on various two-component multiple schedules. The first component contained either a variable-interval 1-min schedule of immediate reinforcement or an extinction schedule and was associated with a plain white key (S1). The second component contained a variable-interval 1-min schedule of delayed reinforcement and was associated with a black line on a white background (S2). The major results showed that (a) decremental gradients were obtained around the stimulus associated with the delayed reinforcement component when S1 was associated with extinction, but that incremental gradients were obtained when S1 was associated with immediate reinforcement, (b) the subjects' pretraining did not affect the generalization gradients if sufficient training on the terminal multiple schedule was provided, and (c) changing the S1 schedule from immediate reinforcement to extinction produced behavioral contrast if reinforcement was delayed for 10 sec during S2, but not if it was delayed for 20 sec.     

A comparative analysis of North American adolescent and adult mass murderers

Thirty adult mass murderers and 34 adolescent mass murderers in North America are compared on both offender and offense variables to delineate similarities and differences. Findings indicate a plethora of psychiatric disturbances and odd/reclusive and acting-out personality traits. Predisposing factors include a fascination with weapons and war among many of the adolescents and the development of a "warrior mentality" in most of the adults. Precipitating factors indicate a major rejection or loss in the hours or days preceding the mass murder. Results are interpreted through the lens of threat assessment for targeted violence (Borum, Fein, Vossekuil, & Bergland 1999), recognizing that a fact-based, dynamic behavioral approach is most useful for mitigating risk of such an extremely low-base-rate violent crime.