Inhibitory Control in Children with Frontal Infarcts Related to Sickle Cell Disease

Evidence from past studies indicates that children with traumatic brain injury experience difficulties with inhibitory control. Less is known about inhibitory control in children with frontal brain injury related to cerebral infarction. We compared the inhibitory performance of children with frontal infarcts related to sickle cell disease with that of a control group of children with sickle cell disease but no history of cerebral infarction. On a stimulus-response reversal task, children with frontal infarcts made significantly more accuracy errors in the inhibitory condition than controls. Findings from this study and from previous research suggest that impairments in inhibitory control are common following frontal injury in a range of pediatric populations.     

Influence of the restored work-hardening rate on ductility studied by X-ray computed tomography

Abstract

Void growth and coalescence in a model material containing an artificial three-dimensional void array (the estimated local void volume fraction was 1.1%) were investigated by X-ray computed tomography (=XCT). The initially tapered cylindrical voids became elongated along the principal straining direction by some amount of tensile plastic deformation, and then the work-hardening capacity in the intervoid matrix was restored by an intermediate annealing. The annealed model material was pulled in tension all the way up to fracture to see if the existing void coalescence models can predict the void coalescence strain.     

Differentiating core and co-opted mechanisms in calculation: The neuroimaging of calculation in aphasia

The role of language in exact calculation is the subject of debate. Some behavioral and functional neuroimaging investigations of healthy participants suggest that calculation requires language resources. However, there are also reports of individuals with severe aphasic language impairment who retain calculation ability. One possibility in resolving these discordant findings is that the neural basis of calculation has undergone significant reorganization in aphasic calculators. Using fMRI, we examined brain activations associated with exact addition and subtraction in two patients with severe agrammatic aphasia and retained calculation ability. Behavior and brain activations during two-digit addition and subtraction were compared to those of a group of 11 healthy, age-matched controls. Behavioral results confirmed that both patients retained calculation ability. Imaging findings revealed individual differences in processing, but also a similar activation pattern across patients and controls in bilateral parietal cortices. Patients differed from controls in small areas of increased activation in peri-lesional regions, a shift from left fronto-temporal activation to the contralateral region, and increased activations in bilateral superior parietal regions. Our results suggest that bilateral parietal cortex represents the core of the calculation network and, while healthy controls may recruit language resources to support calculation, these mechanisms are not mandatory in adult cognition.     

Modulating younger and older adults’ performance in ignoring pictorial information during a word matching task

Using both behavioural and event-related potential (ERP) data, the current study sought to examine the neurophysiological underpinnings for the effect of distracting pictorial information on semantic word matching performance in younger and older adults. This was tested in the context of semantic relations between task-relevant word pairs, a task-irrelevant picture and the resultant N400 differences in ERP. Younger and older adults were shown a context word superimposed on a to-be-ignored picture, followed by a test word. Their task was to determine whether the prime and test words were semantically related. The to-be-ignored pictures were interfering (for ‘No’ trials), facilitating (for ‘Yes’ trials), or neutral (for both ‘Yes’ and ‘No’ trials) to the expected responses. The interfering and facilitatory effects of to-be-ignored pictures were assessed under more automatic and more controlled conditions by manipulating the context–test interstimulus-interval (ISI) as 50 ms and 1000 ms, respectively. The analysis of the N400 at centro-parietal sites during test word display revealed similar N400 amplitudes for the ‘No’ response trials at the two ISIs, suggesting that younger and older adults showed an equivalent effect from interfering pictures. In contrast, younger adults showed greater reductions in the N400, as compared to older adults, for ‘Yes’ trials indicating differential effects in facilitation from to-be-ignored pictorial information, but only in the long ISI condition. The data are discussed in terms of age differences in resource demanding strategy use during a semantic word matching task, specifically during controlled retrieval.     

Decreased susceptibility to false memories from misinformation in hormonal contraception users

Sex hormones are increasingly implicated in memory formation. Recent literature has documented a relationship between hormones and emotional memory and sex differences, which are likely related to hormones, have long been demonstrated in a variety of mnemonic domains, including false memories. Hormonal contraception (HC), which alters sex hormones, has been associated with a bias towards gist memory and away from detailed memory in women who use it during an emotional memory task. Here, we investigated whether HC was associated with changes in susceptibility to false memories, which may be related to the formation of gist memories. We tested false memory susceptibility using two well-validated false memory paradigms: the Deese–Roediger–McDermott (DRM) task, and a story-based misinformation task. We found that hormonal contraceptive users were less susceptible to false memories compared to non-users in the misinformation task, and no differences were seen between groups on the DRM task. We hypothesise that the differences in false memories from the misinformation task may be related to hormonal contraceptive users' memory bias away from details, towards gist memory.     

The impact of egg incubation temperature on the personality of oviparous reptiles

Personality traits, defined as differences in the behavior of individual animals of the same species that are consistent over time and context, such as ‘boldness,’ have been shown to be both heritable and be influenced by external factors, such as predation pressure. Currently, we know very little about the role that early environmental factors have upon personality. Thus, we investigated the impact of incubation temperature upon the boldness on an oviparous reptile, the bearded dragon (Pogona vitticeps). Eggs, from one clutch, were incubated at two different average temperatures within the normal range. After hatching the lizards were raised under the same environmental conditions. Novel object and novel environment tests were used to assess personality. Each test was repeated in both the short term and the long term. The results revealed that incubation temperature did impact upon ‘boldness’ but only in the short term and suggests that, rather than influencing personality, incubation temperature may have an effect on the development of behavioral of oviparous reptiles at different stages across ontogeny.     

Initial Evidence for the Reliability and Validity of the Sexual Experiences Survey-Short Form Perpetration (SES-SFP) in College Men

This study provides psychometric data on the Sexual Experiences Survey—Short Form Perpetration (SES-SFP), a revision of one of the most widely used measures of sexual perpetration, in a sample of college men. Participants (n = 402) completed a web survey containing the study measures; a subset of 66 participants completed the SES-SFP again 2 weeks later. Our results provide initial evidence of internal consistency and convergent evidence of validity for the SES-SFP in college men but question the measure’s test-retest reliability. The severity of tactics used to coerce sexually aggressive behaviors was more strongly associated with rape empathy than sexual outcome severity scores, indicating utility of assessing coercive tactics. Additional research is needed regarding the psychometric properties of the SES-SFP and other measures of sexual perpetration in order to accurately assess rates of these behaviors and inform preventive interventions.     

Conditionals in Theories of Truth

We argue that distinct conditionals—conditionals that are governed by different logics—are needed to formalize the rules of Truth Introduction and Truth Elimination. We show that revision theory, when enriched with the new conditionals, yields an attractive theory of truth. We go on to compare this theory with one recently proposed by Hartry Field.     

The discounting model selector: Statistical software for delay discounting applications

Original, open‐source computer software was developed and validated against established delay discounting methods in the literature. The software executed approximate Bayesian model selection methods from user‐supplied temporal discounting data and computed the effective delay 50 (ED50) from the best performing model. Software was custom‐designed to enable behavior analysts to conveniently apply recent statistical methods to temporal discounting data with the aid of a graphical user interface (GUI). The results of independent validation of the approximate Bayesian model selection methods indicated that the program provided results identical to that of the original source paper and its methods. Monte Carlo simulation (n = 50,000) confirmed that true model was selected most often in each setting. Simulation code and data for this study were posted to an online repository for use by other researchers. The model selection approach was applied to three existing delay discounting data sets from the literature in addition to the data from the source paper. Comparisons of model selected ED50 were consistent with traditional indices of discounting. Conceptual issues related to the development and use of computer software by behavior analysts and the opportunities afforded by free and open‐sourced software are discussed and a review of possible expansions of this software are provided.     

Using Participatory System Dynamics Modeling to Examine the Local HIV Test and Treatment Care Continuum in Order to Reduce Community Viral Load

Achieving community‐level goals to eliminate the HIV epidemic requires coordinated efforts through community consortia with a common purpose to examine and critique their own HIV testing and treatment (T&T) care system and build effective tools to guide their efforts to improve it. Participatory system dynamics (SD) modeling offers conceptual, methodological, and analytical tools to engage diverse stakeholders in systems conceptualization and visual mapping of dynamics that undermine community‐level health outcomes and identify those that can be leveraged for systems improvement. We recruited and engaged a 25‐member multi‐stakeholder Task Force, whose members provide or utilize HIV‐related services, to participate in SD modeling to examine and address problems of their local HIV T&T service system. Findings from the iterative model building sessions indicated Task Force members’ increasingly complex understanding of the local HIV care system and demonstrated their improved capacity to visualize and critique multiple models of the HIV T&T service system and identify areas of potential leverage. Findings also showed members’ enhanced communication and consensus in seeking deeper systems understanding and options for solutions. We discuss implications of using these visual SD models for subsequent simulation modeling of the T&T system and for other community applications to improve system effectiveness.