Effects of event rate and display time on sustained attention in hyperactive,normal, and control children

Two experiments were conducted to determine whether hyperactive boys have a unique deficit in sustained attention. Groups with DSM-III diagnoses of attention deficit disorder (ADDH), conduct disorder (CD), ADDH+CD, and learning disorder were compared with normal controls on the Continuous Performance Task. In Experiment 1, stimulus presentation rate (stimulus onset asynchrony, SOA) and display time were varied to manipulate attentional demand, and speed and accuracy of performance were measured. The ADDH group was uniquely affected, with less accurate performance at the fastest and slowest SOA. To distinguish the effects of time on task and SOA, the duration of each SOA condition was held constant in Experiment 2. The poorer performance of the ADDH group at the fastest SOA was no longer evident. This finding indicates that the deficit of sustained attention in boys who have ADDH is associated with a greater susceptibility to refractory effects, which is influenced by practice.This research was supported by the Ontario Mental Health and Ruth Schwartz Foundations through a graduate fellowship awarded to P. Chee and a research grant to R. Schachar, G. Logan, and R. Wachsmuth. Dr. Schachar was also supported by the Canadian Psychiatric Research Foundation. This article is based, in part, on a doctoral dissertation submitted by the first author to the Ontario Institute for Studies in Education. The authors thank Dr. John Lovering and the staff of the Departments of Psychiatry and Psychology, The Hospital for Sick Children, for their cooperation in the conduct of this study. This paper was prepared with the assistance of the Medical Publications Department, The Hospital for Sick Children, Toronto.     

Generalization of prism adaptation

Prism exposure produces 2 kinds of adaptive response. Recalibration is ordinary strategic remapping of spatially coded movement commands to rapidly reduce performance error. Realignment is the extraordinary process of transforming spatial maps to bring the origins of coordinate systems into correspondence. Realignment occurs when spatial discordance signals noncorrespondence between spatial maps. In Experiment 1, generalization of recalibration aftereffects from prism exposure to postexposure depended upon the similarity of target pointing limb postures. Realignment aftereffects generalized to the spatial maps involved in exposure. In Experiment 2, the 2 kinds of aftereffects were measured for 3 test positions, one of which was the exposure training position. Recalibration aftereffects generalized nonlinearly, while realignment aftereffects generalized linearly, replicating Bedford (1989, 1993a) using a more familiar prism adaptation paradigm. Recalibration and realignment require methods for distinguishing their relative contribution to prism adaptation.     

The Personal Expansion Questionnaire: Measuring one’s tendency to expand through novelty and augmentation

Previous research indicates that self-expansion, or acquiring a partner’s resources by “including the other in the self”, benefits satisfaction in romantic relationships (Aron, Mashek, &; Aron, 2004). The present investigation seeks to broaden traditional conceptualizations of self-expansion by integrating it with principles of social penetration theory (Taylor, 1968) and considering expansion not only as a dyadic process, but also an individual personality trait. We have termed the newly conceptualized construct “personal expansion”. Three separate studies (N = 172 married adults, 606 undergraduate students, and 129 additional undergraduates, respectively) are presented to validate the Personal Expansion Questionnaire; a 10-item self-report scale developed to measure this newly defined construct. Results indicate a two factor structure underlying personal expansion. Both convergent and discriminant validity are established in comparison to one’s individual needs, affective traits, and the Big Five personality factors. Finally, test-retest reliability for the PEQ is demonstrated across five weeks. Consideration is given to the unique ways that personal expansion may be particularly relevant to long-term relationship success at both the individual and dyadic level.     

Social contexts influence ethical considerations of research

This article argues that we could improve the design of research protocols by developing an awareness of and a responsiveness to the social contexts of all the actors in the research enterprise, including subjects, investigators, sponsors, and members of the community in which the research will be conducted. "Social context" refers to the settings in which the actors are situated, including, but not limited to, their social, economic, political, cultural, and technological features. The utility of thinking about social contexts is introduced and exemplified by the presentation of a hypothetical case in which one central issue is limitation of the probability of injury to subjects by selection of individuals who are not expected to live long enough for the known risks of the study to become manifest as harms. Benefits of such considerations may include enhanced subject satisfaction and cooperation, community acceptance, and improved data quality, among other desirable consequences.     

The role of muscle tension in “repression”

Using an active partial avoidance conditioning paradigm, muscle tension was conditioned to a verbal conditional stimulus (CS), and recall of words semantically unrelated and related to the CS was tested under conditions of three levels of induced muscle tension with 20 subjects (Ss). Results showed the expected decrease in latency of response with moderate tension for all stimuli during the pretreatment period and for the unrelated words during the posttreatment period and a significant increase in latency of response for the related words during the posttreatment period. It is suggested that if the level of muscle tension associated with the conditional response (CR) is induced in Ss, then recall of CS-related material will be inhibited or “repressed.”     

The carry-over effect of competition: The impact of competition on prejudice towards uninvolved outgroups

Following realistic group-conflict theory, negative interdependence between groups (e.g., competition) leads to prejudice towards the opposing outgroup. Based on research on mindset priming, it is hypothesized that competition increases prejudice, regardless of whether the derogated outgroup is involved in the competition or not. In Experiment 1, participants remembered an event involving either competition or cooperation; in Experiments 2 and 3 they participated in a competitive, cooperative, or individual assessment of their knowledge. Subsequent measures indicated that competition results in higher levels of prejudice, even when it is not related to the intergroup context. Additional evidence suggests that this effect is not driven by the transfer of negative affect or ego-depletion. Possible underlying cognitive processes are discussed.     

Does magical thinking produce neutralising behaviour? An experimental investigation

Magical thinking is of relevance to obsessive compulsive disorder (OCD), and has been most widely investigated in relation to the cognitive bias known as thought-action fusion (TAF). This is seen as playing a role in the formation of fears about responsibility for harm. We suggest that magical thinking may also characterise some types of neutralising behaviour, which arise in response to those fears, and are a hallmark of the disorder. In an experimental study of 51 undergraduate students, we assessed whether the use of neutralising behaviours in response to an induction of fears of increasing likelihood for harm is related to a propensity for magical thinking. The 75.5% of participants demonstrated at least one form of neutralising behaviour in response to a TAF-induction task. Neutralising was associated with stronger and more persistent responses to the task, and with questionnaire measures of magical ideation. Those who neutralised did not report higher levels of OCD symptoms. It appears that neutralising is a common response in circumstances that provoke a sense of responsibility for harm. Its occurrence may be linked to magical thinking, however, the results from this experimental investigation suggested that this process may not be specific to OCD.     

A note on using stratified alpha to estimate the composite reliability of a test composed of interrelated nonhomogeneous items

The relationship between stratified alpha (alpha(s)) and the reliability of a test composed of interrelated nonhomogeneous items is examined. It is mathematically demonstrated that when there is congeneric equivalence within the strata or subtests, the difference between the coefficients is a function of the variances of the loadings within the strata. When the items within each stratum are essentially tau equivalent, these variances are 0, and alpha(s) and true reliability are equal, provided errors of measurement are uncorrelated. If errors of measurement are positively correlated and there is essential tau equivalence within strata, stratified alpha will overestimate reliability. These findings indicate that recent studies involving stratified alpha (A. Kamata, A. Turhan, & E. Darandari, 2003; H. G. Osburn, 2000) need to be interpreted with some degree of caution. Nevertheless, the hypothetical population data presented in this article suggest that under certain circumstances, stratified alpha can be considerably greater than alpha and closer to the true reliability. Because the former is easily computed, it is recommended that with stratified tests, practicing researchers should routinely calculate both alpha and stratified alpha coefficients.