The role of edges in object recognition by pigeons

In three experiments, we explored how pigeons use edges, corresponding to orientation and depth discontinuities, in visual recognition tasks. In experiment 1, we compared the pigeon's ability to recognize line drawings of four different geons when trained with shaded images. The birds were trained with either a single view or five different views of each object. Because the five training views had markedly different appearances and locations of shaded surfaces, reflectance edges, etc, the pigeons might have been expected to rely more on the orientation and depth discontinuities that were preserved over rotation and in the line drawings. In neither condition, however, was there any transfer from the rendered images to the outline drawings. In experiment 2, some pigeons were trained with line drawings and shaded images of the same objects associated with the same response (consistent condition), whereas other pigeons were trained with a line drawing and a shaded image of two different objects associated with the same response (inconsistent condition). If the pigeons perceived any correspondence between the stimulus types, then birds in the consistent condition should have learned the discrimination more quickly than birds in the inconsistent condition. But, there was no difference in performance between birds in the consistent and inconsistent conditions. In experiment 3, we explored pigeons' processing of edges by comparing their discrimination of shaded images or line drawings of four objects. Once trained, the pigeons were tested with planar rotations of those objects. The pigeons exhibited different patterns of generalization depending on whether they were trained with line drawings or shaded images. The results of these three experiments suggest that pigeons may place greater importance on surface features indicating materials, such as food or water. Such substances do not have definite boundaries cued by edges which are thought to be central to human recognition.     

Fractionating working memory: consolidation and maintenance are independent processes

In the present study, we required subjects to remember simple objects that were masked to interrupt consolidation and allow us to estimate the rate of information accrual in visual working memory. We compared a consolidation-baseline condition with a consolidation-during-maintenance condition in which subjects needed to remember a set of unmasked items and then were shown to-be-remembered masked items. We hypothesized that if the control processes of consolidation and maintenance are performed by common mechanisms, then consolidation should be less efficient when performed during maintenance than when performed alone. However, we found that an identical amount of information was encoded per unit time in the two conditions. These results indicate that working memory consolidation is not slowed by maintenance and suggest a two-step model of encoding in visual working memory.     

Inhibition of return in children with Tourette's syndrome and comorbid forms: a preliminary study.

BACKGROUND: This study investigated the nature and functioning of the visual-spatial inhibition of return (IOR) phenomenon in children with "pure" Tourette's syndrome (TS), and those with comorbid forms of TS. METHOD: Children with TS-only and "TS + comorbid" (TS + ADHD +/- OCD) and matched controls performed the inhibition of return (IOR) task, which involved responding to left and right visual targets appearing on a computer screen that were preceded by congruent or incongruent exogenous visual cues. RESULTS: The TS-only group performed similarly on the IOR task to the controls. When the TS-only group was subdivided into children with mild and severe TS symptoms, a post hoc comparison between the controls and severe TS symptom children revealed that these TS children had a reduced magnitude of IOR for targets appearing in the right visual field. The comparison between the TS + comorbid and controls revealed an atypical IOR pattern for the TS + comorbid group. They displayed a loss of normal facilitatory and inhibitory effects for right visual field targets. CONCLUSIONS: The findings suggest abnormalities in attentional "disengage" and "move" mechanisms in TS when directing attention to the right visual field, which may reflect left posterior parietal, superior colliculus, and midbrain pathology.     

Disseminating a smokeless tobacco cessation intervention model to dental hygienists: a randomized comparison of personalized instruction and self-study methods.

This study evaluated 2 methods of disseminating an empirically validated smokeless tobacco intervention delivered during routine dental care. Twenty cities within 12 states were stratified and then randomized to 1 of 3 groups: personalized instruction (PI), self-study (SS), or delayed training (DT) control. Dental hygienists in the SS condition were sent a manual and video. Those in the PI condition were recruited to attend a workshop. Thirty-seven percent of eligible hygienists agreed to participate. At 12 months postenrollment, hygienists in the SS and PI conditions significantly increased their "Assist" behaviors (discuss cessation techniques, help patient set a quit date, and provide cessation materials) and reported fewer perceived barriers to delivering the intervention as compared with hygienists in DT. An economic analysis suggests that SS is more cost-effective than PI.     

Psychometric evaluation of the restructured clinical scales of the MMPI-2

Conceptual overlap and heterogeneity have long been noted as weaknesses of the Minnesota Multiphasic Personality Inventory's clinical scales. Restructured clinical (RC) scales recently were developed to address these concerns (A. Tellegen et al., 2003). The authors evaluated the psychometric properties of the RC scales in psychology clinic clients (N=285) and military veterans (N=567). The RC scales were as internally consistent as the clinical scales and correlated strongly with their original counterparts (except for RC3/Hysteria). They also were less intercorrelated, produced conceptually clearer relations with measures of personality and psychopathology, and yielded somewhat greater incremental utility than the clinical scales. Thus, the RC scales demonstrated several psychometric strengths while utilizing 60% fewer items, but the 2 sets of scales cannot be used interchangeably. Interpretive considerations are discussed.     

Assessing aggression in adolescent romantic relationships: can we do it better?

Almost all research on aggression in adolescent romantic relationships makes use of 1-time, retrospective assessment methods. In the present research, the authors compared data on the experience of adolescent relationship aggression (physical aggression and threatening behavior) collected from 125 high school students via 2 methods: (a) a 1-time, 2-month retrospective assessment and (b) a cumulative method based on four 2-week retrospective assessments, each spaced 2 weeks apart. For the cumulative method, data from the 4 assessments were aggregated to cover the same time period as the single, 2-month retrospective assessment. A greater proportion of the sample (48.0%) reported experiencing physical aggression using the cumulative method compared with the single, 2-month retrospective method (27.0%). The prevalence of threatening behavior was also higher using the cumulative method (48.8% vs. 24.8%). Adolescent trauma and anxiety symptoms correlated more strongly with physical aggression data derived from the cumulative method than from the 1-time assessment method.     

Metabolic and endocrine disturbances in psychiatric disorders: a multidisciplinary approach to appropriate atypical antipsychotic utilization

Patients with psychiatric disorders have an increased rate of cardiovascular morbidity and mortality compared with the general population. Metabolic issues such as weight gain, dyslipidemia, diabetes mellitus, diabetic ketoacidosis,and pancreatitis have been reported with the use of antipsychotic agents. Although atypical antipsychotics have not been linked directly to the development of metabolic syndrome, these medications have been shown to increase risk factors that can lead to metabolic and endocrine disturbances. Therefore, clinicians should provide ongoing monitoring for patients who are being treated for psychiatric disorders with these agents. According to the 2004 Consensus Report on Antipsychotics, screening measures should include baseline and follow-up monitoring of personal/family histories, weight (body mass index), waist circumference, blood pressure, fasting plasma glucose, and fasting lipid profile.     

The role of a language scale for infant and preschool assessment

The PLS-4 (Preschool Language Scale, 4th edition) is a psychometrically sound instrument constructed to assess language skills in children from birth to 6 years 11 months. It is a useful diagnostic and research tool that can be used to identify current comprehension and expressive language skills and can measure changes in language skills over time. The test is individually administered and includes tasks that assess skills in the areas of preverbal behaviors, as well as linguistic skills in the areas of semantics, morphology, syntax, integrative language skills, and preliteracy skills. Extensive reliability and validity evidence are presented. The test has been used extensively in research examining language development of young children from different home environments, children with identified medical conditions, and children participating in a variety of habilitation and intervention programs. Both the previous edition (PLS-3) and the new PLS-4 English and Spanish editions are used extensively in clinical, medical, and research settings to examine developmental language patterns of infants, toddlers, and preschoolers.