Dissociating effects of subclinical anxiety and depression on cognitive control

Even at subclinical levels, anxiety and depression are associated with impaired cognitive control. It is unclear, though, to what extent these deficits reflect a common underlying dysfunction. Using a non-affective hybrid masked prime-Simon task, we obtained several measures of within- and between- trial inhibitory behavioral control in 80 young, healthy volunteers, together with measures of their anxiety and depression levels. Neither depression nor anxiety affected low-level within-trial control, or any of the between-trial control measures. However, increased levels of depression, but not of anxiety, were associated with impaired high-level within-trial control (increased Simon effect). Results indicate that depression, but not anxiety, impairs voluntary online response-control mechanisms independent of affective content.     

Sampling and Data Collection Methods in Sales Force Research: Issues and Recommendations for Improvement

Samples used in sales force research studies found in JM, JMR, JPSSM, and IMM over a seventeen year period were examined to discover the extent to which sales force sampling has met the issues of covering different industries and types of salespeople, of satisfying technical sampling requirements, and of clearly reporting on sampling methods. Recommendations for improving standards for conducting and reporting sales force sampling methodology in terms of the resources available are offered.     

Processing Speed Weakness in Children and Adolescents with Non-Hyperactive but Inattentive ADHD (ADD)

DSM-IV-TR defines ADHD-Predominantly Inattentive as allowing up to five symptoms of hyperactivity/impulsivity, while theories of the inattentive type usually assume a group that is hypoactive and characterized by processing speed and cognitive interference deficits. In a community-recruited sample of 572 children and adolescents, a pure inattentive subtype of ADHD (ADD) was defined as those who met DSM-IV-TR criteria for ADHD-PI but had two or fewer hyperactive/impulsive symptoms. Processing and output speeds of those with ADD were compared to those identified with DSM-IV-TR ADHD combined type and non-ADHD controls. These results were then contrasted with those found when DSM-IV-TR defined ADHD-PI was compared with ADHD-C and controls. Processing and output speed were assessed with the Trailmaking A and B and the Stroop Naming Tests. Cognitive interference control was assessed with the interference score from the Stroop Task. Slower cognitive interference speed was found in the ADD vs. ADHD-C and controls comparisons, but not the ADHD-PI versus ADHD-C and controls comparisons. On output speed measures, ADD exhibited the slowest performance, significantly different from controls and the effect size for the set-shifting speed contrast (Trailmaking B) was double that of the ADHD-PI vs. control comparison. ADHD-Inattentive type as defined by the DSM-IV-TR is a heterogeneous condition with a meaningful proportion of those affected exhibiting virtually no hyperactive/impulsive symptoms. This subgroup may represent a distinct inattentive condition characterized by poor cognitive interference control and slow processing or output speed.     

Effective Hamiltonian of the two-band Hubbard model: An exact result

An effective Hamiltonian for the two-band Hubbard model was derived by a canonical transformation which was calculated and summed up to infinite order . The transformed Hamiltonian contains terms with strongly renormalized interaction energies. These new interaction energies show sign reversals as a function of the hopping integral in addition to a strong reduction in the charge-transfer gap and a significant increase in the attractive oxygen Hubbard term.     

Prediction of termination migration of a rod-type particle in Ti–6Al–4Fe alloy

The kinetics for the termination migration of a rod-type alpha particle in a two-phase Ti alloy was predicted on the basis of the edge recession theory. The developed model quantified the effect of geometrical dimensions and diffusional factors on the spheroidization rate. Comparison with the experimental results of Ti–6Al–4Fe showed that the model can provide a reasonable prediction of the time to complete the static spheroidization of rod-type particles.     

Predicting eating problems among Malaysian Chinese: Differential roles of positive and negative perfectionism

Positive and negative perfectionism (measured by the Positive and Negative Perfectionism Scale; PANPS) are found to have differential roles in predicting eating problems. This study translated and back-translated the PANPS into Chinese and then examined whether its factor structure was comparable to the original PANPS. The relationships between positive and negative perfectionism (using Chinese PANPS) and eating problems were also evaluated. Malaysian Chinese (N = 205) adults completed the Chinese PANPS, Eating Disorder Inventory (EDI) and Marlowe-Crowne Social Desirability Scale. Principal Component Analysis showed the two-factor solution of the Chinese PANPS accounted for 33.42% of the total variance, which was comparable to previous studies. Hierarchical multiple regressions revealed that negative perfectionism significantly predicted all eating disorder symptoms for females, but not drive for thinness and body dissatisfaction for males. Conversely, positive perfectionism significantly predicted lower total EDI scores, lower ineffectiveness and lower interpersonal distrust, but only predicted lower body dissatisfaction among females. In conclusion, negative perfectionism was consistently associated with eating problems whereas positive perfectionism might be a potentially adaptive factor, confirming the distinctive roles each played in the development of eating problems, even in a non-Western population.     

The First Twenty Years of the Will and the Ways: An Examination of Score Reliability Distribution on Snyder’s Dispositional Hope Scale

C. R. Snyder has established hope theory as an important contributor to positive psychology. As the empirical evidence continues to grow, hope researchers need to have confidence that their measures will produce reliable scores. This study presents a reliability generalization on both the internal consistency and test–retest reliability estimates from Snyder’s dispositional hope scale. While over 300 published works were found to have cited the target article 74 present internal consistency scores and 17 reported scores for test–retest reliability. The results of the reliability generalization suggest support for the score reliabilities produced by the dispositional hope scale. However, internal consistency was higher for studies using the eight-item response format (α = 0.82) compared to those using the four-item response format (α = 0.77). Additionally, the test–retest score reliability was high 0.80 with no statistically significant differences by response format. Findings also demonstrated that score reliability estimates were not significantly influenced by the coded sample characteristics.     

Subjective Difficulty of Movements With Ongoing Visual Control

Objective difficulty of a single-component visually controlled movement may be defined by Fitts's (1954) Index of Difficulty, which is a measure of difficulty in the sense that movement time is linearly related to the objective measure. For movements that have multiple components, it becomes difficult to determine an objective measure of task difficulty due to unknown interactions between components of the movement and interactions with other factors. Thus, it may be necessary to use indirect methods for allocating a measure of task difficulty. The purpose of the study was to determine whether participants could validly construct a subjective measure of the movement difficulty and whether this measure was related to the known objective measure of difficulty. Experiments showed that for single-component movements, there was a close relationship between measures of subjective and objective difficulty. With two-component visually controlled movements it was found that subjective difficulty could be related to objective difficulty, but not as simply as for single-component tasks.     

Maturational Changes in Canadian Adolescents' Cognitive Attitudinal Structure Concerning Marijuana

Thirty-four items concerning marijuana use were administered three times to a cohort of Canadian high school students between Grades 11 and 13, in 1977 (n = 439), 1978 (n = 419), and 1979 (n = 167). These items were designed to measure four distinct constructs: attitude, perceived peer approval or disapproval, concern about risks, and symbolic protest against conventional society. A cross-sectional factor analysis of the Grade 13 data supported the hypothesized factor structure, as had earlier work with college students. However, analogous analyses on the Grade 11 and Grade 12 data contradicted the hypothesized factor structure. Most notably, separate factors for positive and negative attitude appeared in the Grade 11 and 12 analyses. The data were interpreted primarily in terms of maturational changes, largely through elimination of alternative interpretations by internal analyses and previous findings. Implications were discussed for adolescent cognitive-attitudinal development, attitude theory, and analysis of panel data.