Atypical neural functions underlying phonological processing and silent rehearsal in children who stutter

Phonological processing was examined in school-age children who stutter (CWS) by assessing their performance and recording event-related brain potentials (ERPs) in a visual rhyming task. CWS had lower accuracy on rhyming judgments, but the cognitive processes that mediate the comparisons of the phonological representations of words, as indexed by the rhyming effect (RE) ERP, were similar for the stuttering and normally fluent groups. Thus the lower behavioral accuracy of rhyming judgments by the CWS could not be attributed to that particular stage of processing. Instead, the neural functions for processes preceding the RE, indexed by the N400 and CNV elicited by the primes and the N400 elicited by the targets, suggest atypical processing that may have resulted in less efficient, less accurate rhyming judgment for the CWS. Based on the present results, it seems likely that the neural processes related to phonological rehearsal and target word anticipation, as indexed by the CNV, are distinctive for CWS at this age. Further, it is likely that the relative contributions of the left and right hemispheres differ in CWS in the stage of processing when linguistic integration occurs, as indexed by the N400. Taken together, these results suggest that CWS may be less able to form and retain a stable neural representation of the prime onset and rime as they anticipate the target presentation, which may lead to lower rhyming judgment accuracy.     

Why Take Both Boxes?

The crucial premise of the standard argument for two‐boxing in Newcomb's problem, a causal dominance principle, is false. We present some counterexamples. We then offer a metaethical explanation for why the counterexamples arise. Our explanation reveals a new and superior argument for two‐boxing, one that eschews the causal dominance principle in favor of a principle linking rational choice to guidance and actual value maximization.     

Age-related decline of sleep-dependent consolidation

Sleep-dependent memory consolidation is observed following motor skill learning: Performance improvements are greater over a 12-h period containing sleep relative to an equivalent interval without sleep. Here we examined whether older adults exhibit sleep-dependent consolidation on a sequence learning task. Participants were trained on one of two sequence learning tasks. Performance was assessed after a 12-h break that included sleep and after a 12-h break that did not include sleep. Older and younger adults showed similar degrees of initial learning. However, performance of the older adults did not improve following sleep, providing evidence that sleep-dependent consolidation is diminished with age.     

Unifying representations and responses: perseverative biases arise from a single behavioral system

Abstract— A dominant account of perseverative errors in early development contends that such errors reflect a failure to inhibit a prepotent response. This study investigated whether perseveration might also arise from a failure to inhibit a prepotent representation. Children watched as a toy was hidden at an A location, waited during a delay, and then watched the experimenter find the toy. After six observation-only A trials, the toy was hidden at a B location, and children were allowed to search for the toy. Two- and 4-year-olds' responses on the B trials were significantly biased toward A even though they had never overtly responded to this location. Thus, perseverative biases in early development can arise as a result of prepotent representations, demonstrating that the prepotent-response account is incomplete. We discuss three alternative interpretations of these results, including the possibility that representational and response-based biases reflect the operation of a single, integrated behavioral system.     

Scaling a motor skill through observation and practice

The authors examined the proposal that a motor skill is scaled through physical practice and not through observation of a model. In 4 groups, participants (N = 32) did or did not imitate a model bowling a ball to a target 8 m away. In an assessment phase, those groups did or did not observe the same model bowling a ball to a target 4 m away. Participants who viewed a model in the assessment phase were more accurate and consistent in terms of bowling accuracy than were those who did not. Their shoulder and wrist velocity profiles were more similar to those of the 4-m model than were those of the no-model group. Participants who had previous practice and viewed a demonstration were more accurate at scaling the wrist of the bowling arm. Observing a demonstration facilitates the acquisition of control-related features of a movement. Furthermore, early acquisition of coordination aids the use of velocity information for scaling the endpoint of the primary effector.     

Visual form-processing deficits in autism

People with autism have a number of reported deficits in object recognition and global processing. Is there a low-level spatial integration deficit associated with this? We measured spatial-form-coherence detection thresholds using a Glass stimulus in a field of random dots, and compared performance to a similar motion-coherence task. A coherent visual patch was depicted by dots separated by a rotational transformation in space (form) or space-time (motion). To measure parallel visual integration, stimuli were presented for only 250 ms. We compared detection thresholds for children with autism, children with Asperger syndrome, and a matched control group. Children with autism showed a significant form-coherence deficit and a significant motion-coherence deficit, while the performance of the children with Asperger syndrome did not differ significantly from that of controls on either task.     

Training raters to assess adult ADHD: reliability of ratings

The standardization of ADHD ratings in adults is important given their differing symptom presentation. The authors investigated the agreement and reliability of rater standardization in a large-scale trial of atomoxetine in adults with ADHD. Training of 91 raters for the investigator-administered ADHD Rating Scale (ADHDRS-IV-Inv) occurred prior to initiation of a large, 31-site atomoxetine trial. Agreement between raters on total scores was established in two ways: (a) by Kappa coefficient (rater agreement for each item with the percentage of raters that had identical item-by-item scores) and (b) intraclass correlation coefficients (reliability). For the ADHDRS-IV-Inv, rater agreement was moderate, and reliability, as measured by Cronbach's alpha, was substantial. The data indicate that clinicians can be trained to reliably evaluate ADHD in adults using the ADHDRS-IV-Inv.     

Crafting identities and accessing opportunities post-Brown

Decades following Brown v. Board of Education (1954), issues regarding the effects of skin color, poverty, and racial differences in the availability of protective factors persist. For a multiethnic sample of mainly African American (56%), female (69%), and high-achieving (65%) youths, a dual-axis model of vulnerability is used to compare four groups of youths identified as high, masked, low, and undetermined vulnerability on the basis of the presence of risk and protective factors. Risks included level of poverty, number of parents in home, and skin-color pigmentation. Protective factors included youths' perceptions of school climate, parental monitoring, and consonance between skin pigmentation and preferred skin color. The author suggests that 50 years post-Brown, issues concerning White privilege, color stereotyping, power discrepancies, and economic disparities maintain "invisible" and persistent hurdles for vulnerable youths who vary on available protective factors. Findings confirm the impact of vulnerability on psychosocial and achievement outcomes.