Age of acquisition: its neural and computational mechanisms

The acquisition of new skills over a life span is a remarkable human ability. This ability, however, is constrained by age of acquisition (AoA); that is, the age at which learning occurs significantly affects the outcome. This is most clearly reflected in domains such as language, music, and athletics. This article provides a perspective on the neural and computational mechanisms underlying AoA in language acquisition. The authors show how AoA modulates both monolingual lexical processing and bilingual language acquisition. They consider the conditions under which syntactic processing and semantic processing may be differentially sensitive to AoA effects in second-language acquisition. The authors conclude that AoA effects are pervasive and that the neural and computational mechanisms underlying learning and sensorimotor integration provide a general account of these effects.     

Benchmarking Treatment Effectiveness of Community‐Delivered Trauma‐Focused Cognitive Behavioral Therapy

It is critical for urban youth with post‐traumatic stress disorder (PTSD) living in poverty to have access to evidence‐based interventions for their traumatic stress. However, there is limited research on the effectiveness of these interventions when provided in urban, community settings. The objectives of the current study are to (a) evaluate the effectiveness of trauma‐focused cognitive behavioral therapy delivered from 2013 to 2016 in 15 behavioral health agencies on youth (N = 114) PTSD as well as  general mental health symptoms and  functioning, and (b) benchmark these clinical outcomes against other published efficacy and effectiveness trials. Effectiveness data are from the Philadelphia County Community Behavioral Health System, a system that has invested significantly in the training and ongoing support of clinicians providing high‐quality trauma services to youth since 2012. From baseline to last assessment, youth PTSD symptom severity (d = 0.34), PTSD functional impairment (d = 0.38), and overall mental health problem severity (d = 0.29) improved. The effect sizes of  improvements were smaller than effect sizes observed in efficacy and effectiveness studies. This study is the first benchmarking study of TF‐CBT and provides preliminary findings with regard to the effectiveness, and transportability, of TF‐CBT to urban community settings that serve youth in poverty.     

Evidence for adaptive shoulder-elbow control in cyclical movements with different amplitudes, frequencies, and orientations

The evolution of joint dynamics and muscle patterning in the shoulder and elbow was studied for cyclical line drawing tasks at different frequencies, amplitudes, and orientations in the horizontal plane. Three main modes of control were identified: elbow-centered, shoulder-centered, and elbow-shoulder, each referring to the principal joints or joint combinations that were used to achieve the behavioral goals. The contribution of the shoulder joint was most prominent across the majority of movement orientations and largely paralleled changes in the dynamic (inertial) forces in the end effector (shoulder-centered control). The two joints either exchanged roles during the performance of the right diagonal movement (elbow-centered control) or shifted from a single-joint strategy to a dual-joint strategy during the performance of large amplitudes with low or medium cycling frequencies (shoulder-elbow control). These behavioral results support the existence of a modular control mode that allows the central nervous system to effectively tune motor commands to meet a broad variety of orientations, amplitudes, and frequencies. This refers to the emergence of a context-dependent control mode for the shoulder and elbow that optimizes the implementation of the underlying motor goals under a rich combination of spatial and temporal manipulations.     

Traumatic events and tonic immobility

Tonic immobility is a basic defense strategy which has not been studied in depth in humans. Data suggest that it may be a relatively frequent phenomenon in victims of rape and sexual abuse, but its occurrence has not been systematically explored in other types of trauma. We carried out a retrospective study in a sample of 100 university students to establish whether tonic immobility varies depending on the nature of the worst trauma experienced, defined subjectively by each participant. Immobility was assessed using the Tonic Immobility Scale and traumas were assessed using the modified Traumatic Events Questionnaire. Seventy percent of the sample had experienced trauma of some kind. There were no significant differences in tonic immobility between different types of trauma (e.g., physical abuse, assault or aggression, serious accident), except that the mean tonic immobility score was significantly higher in the group with trauma due to physical/psychological or sexual abuse than in the group with trauma due to receiving news of the mutilation, serious injury, or violent or sudden death of a loved one. We conclude tentatively that tonic immobility may be typical not only of sexual traumas, but of other kinds of directly experienced traumas as well.     

Prevalence of Suicide Risk Factors and Suicide‐Related Outcomes in the National Mental Health Study,Colombia

A community survey in 4,426 adults was undertaken as part of the World Mental Health Survey Initiative reporting the prevalence and risk factors for suicide‐related outcomes in Colombia. Lifetime prevalence estimates of suicide ideation, plans, attempts, and risk factors for suicide‐related outcomes were assessed. Retrospective reports of disorders age‐of‐onset were used to study associations between primary mental disorders and first onset of suicide‐related outcomes. Risks of plans and attempts were highest with ideation early age‐of‐onset and within the first year. The highest risk for ideation and attempt among ideators occurred in the 18–29 age group. After first employment (defined as the first paid job accepted by the respondent) and presence of mental disorders constituted risk factors. Impulse‐control disorders were strongest diagnostic predictors.     

In Search of the Language Switch: An fMRI Study of Picture Naming in Spanish–English Bilinguals

For many years, researchers investigating the brain bases of bilingualism have concentrated on two basic questions. The first concerns the nature of language representation. That is, are a bilinguals' two languages represented in distinct or overlapping areas of the brain. The second basic question in the neuropsychology of bilingualism concerns the neural correlates of language switching, that is, the areas that are active when bilinguals switch from one language to the other. Performance between single-language and dual-language picture naming was compared in a group of six Spanish–English bilinguals using behavioral measures and functional magnetic resonance imaging. Participants showed slower reaction times and increased activation in the dorsolateral prefrontal cortex in the mixed language condition relative to single language condition. There was no evidence that each language was represented in different areas of the brain. Results are consistent with the view that language switching is a part of a general executive attentional system and that languages are represented in overlapping areas of the brain in early bilinguals.