Perceiving distance: a role of effort and intent

Perceiving egocentric distance is not only a function of the optical variables to which it relates, but also a function of people's current physiological potential to perform intended actions. In a set of experiments, we showed that, as the effort associated with walking increases, perceived distance increases if the perceiver intends to walk the extent, but not if the perceiver intends to throw. Conversely, as the effort associated with throwing increases, perceived distance increases if people intend to throw to the target, but not if they intend to walk. Perceiving distance combines the geometry of the world with our behavior goals and the potential of our body to achieve these goals.     

How dogs navigate to catch frisbees

Using micro-video cameras attached to the heads of 2 dogs, we examined their optical behavior while catching Frisbees. Our findings reveal that dogs use the same viewer-based navigational heuristics previously found with baseball players (i.e., maintaining the target along a linear optical trajectory, LOT, with optical speed constancy). On trials in which the Frisbee dramatically changed direction, the dog maintained an LOT with speed constancy until it apparently could no longer do so and then simply established a new LOT and optical speed until interception. This work demonstrates the use of simple control mechanisms that utilize invariant geometric properties to accomplish interceptive tasks. It confirms a common interception strategy that extends both across species and to complex target trajectories.     

Children's competence for assent and consent: a review of empirical findings

This narrative review summarizes the empirical literature on children's competence for consent and assent in research and treatment settings. Studies varied widely regarding methodology, particularly in the areas of participant sampling, situational context studied (e.g., psychological versus medical settings), procedures used (e.g., lab-based vs. real-world approaches), and measurement of competence. This review also identifies several fundamental dilemmas underlying approaches to children's informed consent. These dilemmas, including autonomy versus best interest approaches, legal versus psychological or ethical approaches, child- versus family-based approaches, and approaches that emphasize consent versus those that emphasize assent, have implications for the measurement of children's competence and interpretation of findings. Recommendations for future research in the area of children's informed consent include the use of diverse samples and control groups, development of multidimensional and standardized measures of competence, utilization of multidimensional and standardized measures of competence, utilization of observational methods and longitudinal designs, examination of noncognitive aspects of children's competence and comparison of children's competence for treatment and research decisions.     

Linguistic Analysis of Written Narratives of Caregivers of Children and Adolescents with Chronic Illness: Cognitive and Emotional Processes and Physical and Psychological Health Outcomes

Used linguistic analysis of written narratives of caregivers of hospitalized youth with chronic illness to identify emotional and cognitive processes related to physical and psychological health outcomes following writing. Measures were administered at baseline and 4 months. Experimental group (n = 29) wrote about traumas whereas the control group (n = 24) wrote about summer activities for 20 min on three different days. Compared groups on negative emotion- and cognition-related word use. Tested change in negative emotion- and cognition-related word use as predictors of outcomes in experimental group. Consistent with hypotheses, experimental group used more negative emotion words [F(1, 53) = 77.55, p < .001] and cognition-related words than control group [F(1, 53) = 19.09, p < .001] and an increase in cognition words predicted Physical Health Summary Score on SF-36 (standardized = .37, p < .05). A decrease in negative emotion words was related to Physical Health Summary Score on SF-36 only when entered into regression with change in cognition words (standardized = –.31, p < .05). A decrease in negative emotion together with an increase in cognitive processing facilitated by written emotional disclosure has beneficial effects on physical health-related quality of life.     

Effects of the periodic administration of odor or vibration on a 3-hr. vigilance task

The present study examined performance during 3 hr. of simulated sentry duty with and without the intermittent administration of low-level sensory stimuli (odor or vibration). For odor and control conditions, target-detection latency increased steadily over the course of the 3-hr. session. Administration of a tactile stimulus reduced the increase in detection latency compared to that found in odor and control conditions. For all conditions, there were no significant differences in target-detection frequency, shot accuracy, or friend-foe discrimination. Across all conditions, restlessness (motor activity) increased significantly the first hour and remained elevated for the rest of the session. Subjective measures of workload (NASA-TLX) indicated that the 3-hr. task rated high on physical demand, mental demand, frustration, and overall workload. These findings suggest that the intermittent delivery of a clearly detectable tactile stimulus can reduce reaction-time decrements that occur as time on task increases.     

Associations in the course of personality disorders and Axis I disorders over time

In this study, the authors examined time-varying associations between schizotypal (STPD), borderline (BPD), avoidant (AVPD), or obsessive-compulsive (OCPD) personality disorders and co-occurring Axis I disorders in 544 adult participants from the Collaborative Longitudinal Personality Disorders Study. The authors tested predictions of specific longitudinal associations derived from a model of crosscutting psychobiological dimensions (L. J. Siever & K. L. Davis, 1991) with participants with the relevant Axis I disorders. The authors assessed participants at baseline and at 6-, 12-, and 24-month follow-up evaluations. BPD showed significant longitudinal associations with major depressive disorder and posttraumatic stress disorder. AVPD was significantly associated with anxiety disorders (specifically social phobia and obsessive-compulsive disorder). Two of the four personality disorders under examination (STPD and OCPD) showed little or no association with Axis I disorders.     

Psychosocial factors associated with adolescent boys' reports of dating violence

The prevalence of dating violence, as well as its association with psychosocial factors, was examined among a nationally representative sample of 9th- through 12th-grade U.S. boys (N = 7,434) who completed the 1999 Youth Risk Behavior Survey. The dependent variable was physical dating violence; the independent variables were violence, suicide, substance use, and sexual risk behavior. Unadjusted odds ratios (OR) and 95% confidence intervals (CI) were examined. Multivariate logistic regression was used to examine all significant independent variables from the univariate models. Adjusted OR and 95% CI were examined to assess the significance of these relationships. In terms of prevalence, 9.13% of the boys reported physical dating violence. Boys who reported sad/hopeless feelings (OR = 1.68), had attempted suicide (OR = 2.22), reported fighting (OR = 1.81), had multiple sex partners (OR = 3.53), and reported nonuse of condoms (OR = 1.66) were more likely to report physical dating violence. These findings indicate that physical dating violence among adolescent boys may be a more serious problem than has previously been recognized. It was concluded that intervention programs should include a focus on boys as not only perpetrators but also recipients of dating violence.     

Increasing false recognition rates with confirmatory feedback: a phenomenological analysis

During a simulated witness interrogation, participants were encouraged to confabulate an account consistent with false information concerning a videotaped event. The interviewer verbally affirmed some false responses. Previous research has shown that, a week later, participants often recognize confabulated events that were affirmed by the experimenter as being from the video. What is unclear is whether confirmatory feedback encouraged a change in the mental representation of the confabulated events to fit the original event or confirmation might have merely encouraged a change in beliefs about the event. To further understand the mechanisms that underlie the confirmatory feedback effect, participants were asked to judge the phenomenological experience associated with false recognition.     

Risk profiles of adolescent girls who were victims of dating violence

The prevalence of dating violence, as well as its relationship to potential risk factors, was examined among a nationally representative sample of 9th-through 12th-grade U.S. females (N = 7,824) who completed the 1999 Youth Risk Behavior Survey. The dependent variable was physical dating violence; the independent variables were violence, suicide, substance use, and sexual risk behavior. Unadjusted odds ratios (OR) and 95% confidence intervals were examined, and multivariate logistic regression analysis was conducted to identify the most significant risk factors. It was found that nearly one in ten of the adolescent girls reported dating violence. Twelfth-grade girls had the highest prevalence of dating violence. Girls who were victims of dating violence were more likely to be involved in other violent behaviors, to report extreme sadness and suicidal actions, to use illicit substances, and to engage in risky sexual behavior. Multivariate analysis revealed that dating violence was associated with sad/hopeless feelings (OR = 2.13), binge drinking (OR = 1.96), cocaine or inhalant use (OR = 2.90), multiple sex partners (OR = 2.38), nonuse of condoms (OR = 1.53), and ethnicity, specifically being Black (OR = 2.32) or Hispanic (OR = 1.82). These findings provide further evidence that there is a clustering of risk factors among certain adolescents, specifically girls who experience dating violence.