Separate and shared sources of dual-task cost in stimulus identification and response selection

There is often strong interference if a second target stimulus (T2) is presented before processing of a prior target stimulus (T1) is complete. In the "Psychological Refractory Period" (PRP) paradigm, responses are speeded and interference manifests as increased response time for T2. In the "Attentional Blink" (AB) paradigm, stimuli are masked and responses unspeeded; interference manifests as reduced T2 accuracy. While different causes have usually been considered for PRP and AB phenomena, recent evidence has supported a unified account based on a single, shared restriction on concurrent processing. Here we show that a full assessment of separate and shared resource limitations requires direct comparison of hybrid PRP/AB trials with corresponding pure PRP and AB cases. Randomizing trial types in such a comparison also brings substantial benefit in addressing possible changes in task preparation or readiness. The data from two such experiments--combining speeded auditory (SA) and unspeeded visual (UV) task events--provide clear evidence for both separate and shared resource limitations. Often interference is strongest for T1 and T2 events of the same type, reflecting predominantly different limitations in SA and UV processing. With modest increases in demand, however, interference between different event types can also be made arbitrarily large, reflecting arbitrarily important shared limitations. For even such simple tasks as these, T--T2 interference reflects a combination of relatively local and relatively global sources.     

Dual-task attention deficits in dysphoric mood

The attentional functioning of nondysphoric, mildly dysphoric, and moderately to severely dysphoric college students was tested using the attentional blink (AB) paradigm. These groups performed equally well at reporting a single target appearing in a rapidly presented stream of stimuli. All groups showed an AB, with report sensitivity for a 2nd target being reduced when the 2 targets were presented less than 0.5 s apart. Nondysphoric and mildly dysphoric participants showed the same size ABs, but the ABs for moderately to severely dysphoric participants were larger and longer. As predicted, the results showed that moderately to severely dysphoric individuals have attentional impairments. These impairments, however, were evident only in the more demanding dual-task condition.     

The fit and implementation of sexual harassment law to workplace evaluations

Three studies used videotaped harassment complaints to examine the impact of legal standards on the evaluation of social-sexual conduct at work. Study 1 demonstrated that without legal instructions, college students' judgment strategies were highly variable. Study 2 compared 2 current legal standards, the "severity or pervasiveness test" and a proposed utilitarian alternative (i.e., the rational woman approach). Undergraduate participants taking the perspective of the complainant were more sensitive to offensive conduct than were those adopting an objective perspective. Although the utilitarian altemative further increased sensitivity on some measures, it failed to produce a principled judgment strategy. Finally, Study 3 examined the kinds of errors that full-time workers make when applying the "severity or pervasiveness" test to examine more closely the sensitivity of the subjective approach.     

Effects of caffeine on performance of low intensity tasks

31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit. Subjects were administered the beverage 30 min. prior to performing 12 separate tests assessing basic mathematics, simple response, logical reasoning, hand-eye coordination, and spatial and assembly skills. The Spielberger State Anxiety test was administered immediately after consuming the test beverage and once again at posttest. Analysis showed that caffeine did not significantly affect performance on all tests with the exception of the peripheral awareness (hand-eye coordination) test on which performance was higher after ingesting caffeine. The placebo treatment produced no effect on state anxiety, which contrasted with a significant rise in anxiety after caffeine consumption. State anxiety values were significantly greater after caffeine treatment relative to the placebo at pretest, and this difference persisted at posttest. These results demonstrated that the dose of caffeine increased scores on state anxiety for individuals who consumed less than three caffeinated beverages weekly but had very little effect on performance of low intensity tasks, except for a hand-eye coordination test involving peripheral awareness. Perhaps longer continuous performance of more demanding tasks would be more sensitive.     

Modeling of human posturokinetic movements by a linear feedback system: relations among feedback coefficients

This study describes a method of modeling human trunk and whole body backward bending and suggests a possible neural control strategy. The hypothesis was that the control system can be modeled as a linear feedback system, in which the torque acting at a given joint is a function of the state variables (angular positions and angular velocities). The linear system enabled representation of the feedback system by a gain matrix. The matrix was computed from the kinematics recorded by a movement analysis system and from the joint torques calculated by inverse dynamics. To validate the control model, a comparison was made between the angular kinematics yielded by the model and the experimental data. Moreover, for all subjects, the same relationships between feedback coefficients were found although gain values were different. The study showed that the feedback system is an appropriate model of the strategy from performing an accurate controlled trunk or whole body backward bending in the sagittal plane.     

Community,subjectivity, and intersubjectivity

This paper deals with the notions of subjectivity, intersubjectivity, and community from several different points of view that include subjective and intersubjective agency, a sense of community, the community as a social institution, and the idea of social justice. The context of these considerations can be found in the Community–Social–Psychological approach to social action as it is often practiced in Latin America. A review of these themes is considered important because different models of community intervention and practice may lead to different expressions of community interaction.     

An examination of the response styles theory of depression in third- and seventh-grade children: a short-term longitudinal study

The goal of this study was to test the response styles theory of depression in a sample of 3rd- and 7th-grade children. In addition, we examined whether the relationship between rumination and increases in depressive symptoms is mediated by hopelessness and low self-esteem. The procedure involved an initial assessment in which depressive symptoms, response styles, hopelessness, and self-esteem were assessed. The procedure also involved a follow-up assessment, 6 weeks later, in which depressive symptoms, hopelessness, and self-esteem were reassessed. Children with a ruminative response style exhibited increases in depressive symptoms over the 6-week period. In addition, the relationship between rumination and increases in depressive symptoms was mediated by both hopelessness and low self-esteem. Last, contrary to our hypotheses, neither distraction nor problem-solving response styles predicted decreases in depressive symptoms over the course of the study.     

Stimulus control topographies and tests of symmetry in pigeons

Pigeons were tested for symmetry after A-B training under conditions designed to avoid problems that may prevent its emergence, namely the change of stimulus location in testing relative to training and the lack of requisite discrimination training. In Experiment 1, samples appeared in two locations during baseline training to minimize the impact of stimulus location. Experiments 2 and 3 included multiple-location training along with additional identity and symbolic matching training, respectively, to explicitly train all of the simultaneous and successive stimulus discriminations required for testing. Experiment 4 provided reinforcement for symmetrical matching relations with some stimulus sets (with multiple-location training) prior to symmetry testing with different sets. In all experiments, pigeons showed no evidence of symmetry despite the fact that baseline (A-B) matching transferred to novel locations. Additional tests for reflexivity (Experiment 2) yielded similar outcomes. These results indicate that the change in stimulus location is not the sole reason that pigeons do not show symmetry and increase the plausibility of arguments that symmetry and other indexes of stimulus equivalence may be beyond the capabilities of the pigeon.     

A study of parents of violent children

This study based on in-depth interviews of 25 parents of violent children and a control group of 25 parents of nonviolent children concerned the parents' personalities. Parents were between 22 and 48 years of age and were from middle and lower middle socioeconomic backgrounds. Differences in classification by the nonblinded interviewers of parents into the two groups on six behavior characteristics were significant on chi2 tests. Some recommendations are made for further research.     

Attending to the big picture: mood and global versus local processing of visual information

Two experiments employed image-based tasks to test the hypothesis that happier moods promote a greater focus on the forest and sadder moods a greater focus on the trees. The hypothesis was based on the idea that in task situations, affective cues may be experienced as task-relevant information, which then influences global versus local attention. Using a serial-reproduction paradigm, Experiment 1 showed that individuals in sad moods were less likely than those in happier moods to use an accessible global concept to guide attempts to reproduce a drawing from memory. Experiment 2 investigated the same hypothesis by assessing the use of global and local attributes to classify geometric figures. As predicted, individuals in sad moods were less likely than those in happier moods to classify figures on the basis of global features.