A cascade of rejection and appearance preoccupation: Adolescents’ body dysmorphic symptoms and appearance rejection sensitivity over 4 years

Adolescence is a high-risk period for body image disturbance and appearance concerns. In a cascade model, we examined interrelations of body dysmorphic symptoms (BDS) with appearance rejection sensitivity (ARS) and tested gender moderation. Participants were 397 Australian adolescents (T1 Mage = 11.7, SD = 0.91; 56% girls) who completed six surveys over 4 years. In a random-intercept cross-lag model, two (of five possible) paths showed ARS predicted higher subsequent BDS, and three (of five possible) paths showed BDS predicted higher subsequent ARS. Girls reported more BDS and ARS than boys, and random intercepts of BDS and ARS were correlated with the correlation stronger in girls than boys. Cross-lag BDD-ARS associations over the six waves were not significantly moderated by gender. Overall, girls are at higher risk of appearance concerns than boys, but BDD-ARS cascade effects do not differ between girls and boys.     

Around the world,adolescence is a time of heightened sensation seeking and immature self‐regulation

The dual systems model of adolescent risk‐taking portrays the period as one characterized by a combination of heightened sensation seeking and still‐maturing self‐regulation, but most tests of this model have been conducted in the United States or Western Europe. In the present study, these propositions are tested in an international sample of more than 5000 individuals between ages 10 and 30 years from 11 countries in Africa, Asia, Europe and the Americas, using a multi‐method test battery that includes both self‐report and performance‐based measures of both constructs. Consistent with the dual systems model, sensation seeking increased between preadolescence and late adolescence, peaked at age 19, and declined thereafter, whereas self‐regulation increased steadily from preadolescence into young adulthood, reaching a plateau between ages 23 and 26. Although there were some variations in the magnitude of the observed age trends, the developmental patterns were largely similar across countries.     

Gesture for generalization: gesture facilitates flexible learning of words for actions on objects

Verb learning is difficult for children (Gentner, 1982 ), partially because children have a bias to associate a novel verb not only with the action it represents, but also with the object on which it is learned (Kersten & Smith, 2002 ). Here we investigate how well 4‐ and 5‐year‐old children (N = 48) generalize novel verbs for actions on objects after doing or seeing the action (e.g., twisting a knob on an object) or after doing or seeing a gesture for the action (e.g., twisting in the air near an object). We find not only that children generalize more effectively through gesture experience, but also that this ability to generalize persists after a 24‐hour delay.     

Proximodistal exploration in motor learning as an emergent property of optimization

To harness the complexity of their high‐dimensional bodies during sensorimotor development, infants are guided by patterns of freezing and freeing of degrees of freedom. For instance, when learning to reach, infants free the degrees of freedom in their arm proximodistally, that is, from joints that are closer to the body to those that are more distant. Here, we formulate and study computationally the hypothesis that such patterns can emerge spontaneously as the result of a family of stochastic optimization processes, without an innate encoding of a maturational schedule. In particular, we present simulated experiments with an arm where a computational learner progressively acquires reaching skills through adaptive exploration, and we show that a proximodistal organization appears spontaneously, which we denote PDFF (Proximo Distal Freezing and Freeing of degrees of freedom). We also compare this emergent organization between different arm morphologies—from human‐like to quite unnatural ones—to study the effect of different kinematic structures on the emergence of PDFF.     

Auditory‐motor adaptation is reduced in adults who stutter but not in children who stutter

Previous studies have shown that adults who stutter produce smaller corrective motor responses to compensate for unexpected auditory perturbations in comparison to adults who do not stutter, suggesting that stuttering may be associated with deficits in integration of auditory feedback for online speech monitoring. In this study, we examined whether stuttering is also associated with deficiencies in integrating and using discrepancies between expected and received auditory feedback to adaptively update motor programs for accurate speech production. Using a sensorimotor adaptation paradigm, we measured adaptive speech responses to auditory formant frequency perturbations in adults and children who stutter and their matched nonstuttering controls. We found that the magnitude of the speech adaptive response for children who stutter did not differ from that of fluent children. However, the adaptation magnitude of adults who stutter in response to auditory perturbation was significantly smaller than the adaptation magnitude of adults who do not stutter. Together these results indicate that stuttering is associated with deficits in integrating discrepancies between predicted and received auditory feedback to calibrate the speech production system in adults but not children. This auditory‐motor integration deficit thus appears to be a compensatory effect that develops over years of stuttering.     

Auditory access,language access,and implicit sequence learning in deaf children

Developmental psychology plays a central role in shaping evidence‐based best practices for prelingually deaf children. The Auditory Scaffolding Hypothesis (Conway et al., 2009) asserts that a lack of auditory stimulation in deaf children leads to impoverished implicit sequence learning abilities, measured via an artificial grammar learning (AGL) task. However, prior research is confounded by a lack of both auditory and language input. The current study examines implicit learning in deaf children who were (Deaf native signers) or were not (oral cochlear implant users) exposed to language from birth, and in hearing children, using both AGL and Serial Reaction Time (SRT) tasks. Neither deaf nor hearing children across the three groups show evidence of implicit learning on the AGL task, but all three groups show robust implicit learning on the SRT task. These findings argue against the Auditory Scaffolding Hypothesis, and suggest that implicit sequence learning may be resilient to both auditory and language deprivation, within the tested limits. A video abstract of this article can be viewed at: https://youtu.be/EeqfQqlVHLI [Correction added on 07 August 2017, after first online publication: The video abstract link was added.]     

Human milk cortisol concentration predicts experimentally induced infant fear reactivity: moderation by infant sex

Little consideration has been given to the possibility of human infant development being shaped via lactocrine programming, and by breast milk cortisol levels specifically. Despite animal models indicating that glucocorticoid (GC) exposure via lactation might modify brain development and behavior, only one study has reported that milk cortisol levels were positively associated with infant negative affectivity, especially fearfulness and sadness—early emerging risk factors for internalizing difficulties such as anxiety. The aim of the current study was to investigate whether human milk cortisol is associated with mother‐reported fearfulness and experimentally induced infant fear reactivity. Mother‐infant dyads (n = 65) enrolled in the FinnBrain Cohort Study participated. Breast milk samples were obtained 2.5 months postpartum, and milk cortisol concentrations were ascertained using validated luminescence immunoassay methodology. Infant fear reactivity was assessed using maternal reports 6 months postpartum and in a laboratory 8 months postpartum. There was a significant interaction between infant sex and milk cortisol such that higher milk cortisol was related to higher infant fear reactivity in a laboratory setting in girls (β = 0.36, p = .04) but not in boys (β = ?0.15, p = .40). Milk cortisol was not associated with mother‐reported infant fearfulness. Results suggest that higher human milk cortisol concentrations are associated with elevated experimentally induced fear in infancy. Findings support lactocrine programming, and suggest that mothers may “communicate” vital information about stressful environments via cortisol contained in breast milk, shaping girls' early emotional reactivity.     

Not all phonological awareness deficits are created equal: evidence from a comparison between children with Otitis Media and poor readers

Children with reading difficulties and children with a history of repeated ear infections (Otitis Media, OM) are both thought to have phonological impairments, but for quite different reasons. This paper examines the profile of phonological and morphological awareness in poor readers and children with OM. Thirty‐three poor readers were compared to individually matched chronological age and reading age controls. Their phonological awareness and morphological awareness skills were consistently at the level of reading age matched controls. Unexpectedly, a significant minority (25%) of the poor readers had some degree of undiagnosed mild or very mild hearing loss. Twenty‐nine children with a history of OM and their matched controls completed the same battery of tasks. They showed relatively small delays in their literacy and showed no impairment in morphological awareness but had phonological awareness scores below the level of reading age matched controls. Further analysis suggested that this weakness in phonological awareness was carried by a specific weakness in segmenting and blending phonemes, with relatively good performance on phoneme manipulation tasks. Results suggest that children with OM show a circumscribed deficit in phoneme segmentation and blending, while poor readers show a broader metalinguistic impairment which is more closely associated with reading difficulties.