Diminished testing benefits in young adults with attention-deficit hyperactivity disorder

Memory retrieval has been shown to enhance the long-term retention of tested material; however, recent research suggests that limiting attention during retrieval can decrease the benefits of testing memory. The present study examined whether testing benefits are reduced in young adults with attention-deficit hyperactivity disorder (ADHD). College students with and without ADHD read three short prose passages, each followed by a free recall test, a restudy period or a distractor task. Two days later participants recalled the passages. Although participants without ADHD did not show a significant benefit of testing over restudying, testing did produce recall benefits relative to not taking a test. These testing benefits were diminished in participants with ADHD, who did not show any advantage of testing over either restudying or no test. The absence of testing benefits in the ADHD group is likely due in part to decreased recall on the initial test. These findings have implications for improving educational practices among individuals with ADHD and also speak to the need to examine individual differences in the effectiveness of testing as a learning strategy.     

Context-dependent effects of background colour in free recall with spatially grouped words

Three experiments investigated context-dependent effects of background colour in free recall with groups of items. Undergraduates (N=113) intentionally studied 24 words presented in blocks of 6 on a computer screen with two different background colours. The two background colours were changed screen-by-screen randomly (random condition) or alternately (alternation condition) during the study period. A 30-second filled retention interval was imposed before an oral free-recall test. A signal for free recall was presented throughout the test on one of the colour background screens presented at study. Recalled words were classified as same- or different-context words according to whether the background colours at study and test were the same or different. The random condition produced significant context-dependent effects, whereas the alternation condition showed no context-dependent effects, regardless of whether the words were presented once or twice. Furthermore, the words presented on the same screen were clustered in recall, whereas the words presented against the same background colour but on different screens were not clustered. The present results imply: (1) background colours can cue spatially massed words; (2) background colours act as temporally local context; and (3) predictability of the next background colour modulates the context-dependent effect.     

Risk Orientation,Risk Exposure,and Policy Opinions: The Case of Free Trade

This research offers a general framework for thinking about how individual disposition towards risk influences public policy opinions. Affinity for or aversion to risk is, in part, a stable personality characteristic that interacts with risk and reward messages in complex policy debates. We examine the implications of this for public opinions about free trade with extensions to immigration policy. We argue and find that opinions about policy depend jointly upon one's exposure to potential gains or losses and one's risk orientation. The findings have implications for crafting and framing public policies because they highlight how individual characteristics are likely to shape the public response to policy proposals. Our findings suggest that there may be limits, in the aggregate, to the degree to which elites can alter the level of support for policies through framing or through offering risk‐mitigating policy provisions.     

Agency, authorship, and illusion

Daniel Wegner argues that conscious will is an illusion. I examine the adequacy of his theory of apparent mental causation and whether, if accurate, it suggests that our experience of agency and authorship should be considered illusory. I examine various interpretations of this claim and raise problems for each interpretation. I also distinguish between the experiences of agency and authorship.     

Voluntary response selection in free association

Reaction time (RT) in free association (FA) is assumed to consist of three components: stimulus word encoding, response selection, and response generation. The RT of word naming contains the first and third components only. If response selection is a serial voluntary search it can be manipulated by rewarding response speeding. This would lead the subject to terminate the search sooner. Thus, greater speeding will be achieved for delayed responses, for which search was long, than for undelayed ones. This differential speeding effect was observed in Experriment 1 ( N =17), in which the task was FA. Speeding effect was not differential in Experiment 2, in which the subjects ( N =16) were given a word naming task. Both of these experiments employed a between-subjects design. Their results were replicated in Experiment 3 ( N =13), which employed a within-subject design. The results, taken together, suggest that differential speeding is specific to response selection, in accordance with Flekkoy's (1973 a , 1981) voluntary selection model. However, they are inconsistent with the traditional associonistic models.     

The organisation of musical semantic memory: Evidence from false memories for familiar songs

By adapting a well-known paradigm for studying memory for words—the Deese-Roediger-McDermott or DRM paradigm (Deese, 1959, Roediger & McDermott, 1995)—the two experiments reported here explore memory for song titles and song clips. Participants were presented with five song titles (Experiment 1a) or five 30-second song clips (Experiment 1b) for each of nine popular artists (e.g., Robbie Williams). The most popular song identified for each artist in a pilot task was omitted from the sets of titles/clips. Following a distractor task, participants were asked to write down as many of the songs as they could recall. They were also asked to return a week later and complete a second recall task. Participants falsely recalled a significant number of the related but non-presented songs in both experiments and this increased a week later, while correct recall for presented items decreased. The results are discussed in terms of theory for musical memory as well as in the context of providing a novel method for exploring the organisation of musical memory.     

Relations Between Continuous Performance Test Performance Measures and ADHD Behaviors

The Conners' Continuous Performance Test (CPT) is a neuropsychological task that has repeatedly been shown to differentiate ADHD from normal groups. Several variables may be derived from the Conners' CPT including errors of omission and commission, mean hit reaction time(RT), mean hit RT standard error, d', and . What each CPT parameter actually assesses has largely been based upon clinical assumptions and the face validity of each measure (e.g., omission errors measure inattention, commission errors measure impulsivity). This study attempts to examine relations between various CPT variables and phenotypic behaviors so as to better understand the various CPT variables. An epidemiological sample of 817 children was administered the Conners' CPT. Diagnostic interviews were conducted with parents to determine ADHD symptom profiles for all children. Children diagnosed with ADHD had more variable RTs, made more errors of commission and omission, and demonstrated poorer perceptual sensitivity than nondiagnosed children. Regarding specific symptoms, generalized estimating equations (GEE) and ANCOVAs were conducted to determine specific relationships between the 18 DSM-IV ADHD symptoms and 6 CPT parameters. CPT performance measures demonstrated significant relationships to ADHD symptoms but did not demonstrate symptom domain specificity according to a priori assumptions. Overall performance on the two signal detection measures, d' and , was highly related to all ADHD symptoms across symptom domains. Further, increased variability in RTs over time was related to most ADHD symptoms. Finally, it appears that at least 1 CPT variable, mean hit RT, is minimally related to ADHD symptoms as a whole, but does demonstrate some specificity in its link with symptoms of hyperactivity.     

Using the conditional grade-of-membership model to assess judgment accuracy

Consider the case whereJ instruments are used to classify each ofI objects relative toK nominal categories. The conditional grade-of-membership (GoM) model provides a method of estimating the classification probabilities of each instrument (or judge) when the objects being classified consist of both pure types that lie exclusively in one ofK nominal categories, and mixtures that lie in more than one category. Classification probabilities are identifiable whenever the sample of GoM vectors includes pure types from each category. When additional, relatively mild, assumptions are made about judgment accuracy, the identifiable correct classification probabilities are the greatest lower bounds among all solutions that might correspond to the observed multinomial process, even when the unobserved GoM vectors do not include pure types from each category. Estimation using the conditional GoM model is illustrated on a simulated data set. Further simulations show that the estimates of the classification probabilities are relatively accurate, even when the sample contains only a small percentage of approximately pure objects.The authors thank Max A. Woodbury, Kenneth G. Manton and H. Dennis Tolley for their help and four anonymous Psychometrika reviewers (including an associate editor) for their beneficial expository and technical suggestions. This work was supported by the Dean's Fund for Summer Research, Owen Graduate School of Management, Vanderbilt University.     

Do 5% changes around maximal lactate steady state lead to swimming biophysical modifications?

Our purpose was to examine the swimming biophysical responses at velocities (v) of 97.5, 100 and 102.5% of the maximal lactate steady state (MLSS). Ten elite female swimmers performed three-to-five 30-min constant tests at imposed paces to determine 97.5, 100 and 102.5%MLSS v. Gas exchange, blood lactate concentration ([La-]), stroke rate (SR) and v were determined during each test. The v values at 97.5, 100 and 102.5%MLSS were 1.21 ± 0.07, 1.24 ± 0.07 and 1.27 ± 0.07 m.s⁻¹, respectively. Oxygen uptake (V̇O₂) and Pulmonary ventilation (V̇E) increased as function of v. SR and stroke length (v/SR = SL) increased as a function of v. All measured variables were constant as a function of time at 97.5%MLSS and 100%MLSS. At 102.5%MLSS SR increased (3.5%) and stroke length (SL) decreased (3.5%) as a function of time. While V̇O₂ was constant at 102.5%MLSS, [La-] and V̇E increased as a function of time, suggesting hyperventilation, at v’s of 97.5%MLSS and 100%MLSS swimmers completed the 30 min swim in spite of decreased SL and increased SR. However, the decrease in SL and increased SF were accompanied by increased [La-] and V̇E and resulted in the inability of most swimmers to complete the 30 min swim presumably due to fatigue at 102.5%MLSS.     

What Do People Find Incompatible With Causal Determinism?

Four studies explored people's judgments about whether particular types of behavior are compatible with determinism. Participants read a passage describing a deterministic universe, in which everything that happens is fully caused by whatever happened before it. They then assessed the degree to which different behaviors were possible in such a universe. Other participants evaluated the extent to which each of these behaviors had various features (e.g., requiring reasoning). We assessed the extent to which these features predicted judgments about whether the behaviors were possible in a deterministic universe. Experiments 1 and 2 found that people's judgments about whether a behavior was compatible with determinism were not predicted by their judgments about whether that behavior relies on physical processes in the brain and body, is uniquely human, is unpredictable, or involves reasoning. Experiment 3, however, found that a distinction between what we call “active” and “passive” behaviors can explain people's judgments. Experiment 4 extended these findings, showing that we can measure this distinction in several ways and that it is robustly predicted by two different cues. Taken together, these results suggest that people carve up mentally guided behavior into two distinct types—understanding one type to be compatible with determinism, but another type to be fundamentally incompatible with determinism.