Striatal and Behavioral Responses to Reward Vary by Socioeconomic Status in Adolescents.

Disparities in socioeconomic status (SES) lead to unequal access to financial and social support. These disparities are believed to influence reward sensitivity, which in turn are hypothesized to shape how individuals respond to and pursue rewarding experiences. However, surprisingly little is known about how SES shapes reward sensitivity in adolescence. Here, we investigated how SES influenced adolescent responses to reward, both in behavior and the striatum-a brain region that is highly sensitive to reward. We examined responses to both immediate reward (tracked by phasic dopamine) and average reward rate fluctuations (tracked by tonic dopamine) as these distinct signals independently shape learning and motivation. Adolescents (n = 114; 12-14 years; 58 female) performed a gambling task during functional magnetic resonance imaging. We manipulated trial-by-trial reward and loss outcomes, leading to fluctuations between periods of reward scarcity and abundance. We found that a higher reward rate hastened behavioral responses, and increased guess switching, consistent with the idea that reward abundance increases response vigor and exploration. Moreover, immediate reward reinforced previously rewarding decisions (win-stay, lose-switch) and slowed responses (postreward pausing), particularly when rewards were scarce. Notably, lower-SES adolescents slowed down less after rare rewards than higher-SES adolescents. In the brain, striatal activations covaried with the average reward rate across time and showed greater activations during rewarding blocks. However, these striatal effects were diminished in lower-SES adolescents. These findings show that the striatum tracks reward rate fluctuations, which shape decisions and motivation. Moreover, lower SES appears to attenuate reward-driven behavioral and brain responses.

Improving Children's Expressive Language and Auditory Comprehension Through Responsive Caregiving: Evidence from a Randomized Controlled Trial of a Strength-Based Video-Coaching Intervention.

Young children from low-SES backgrounds are at higher risk for delayed language development, likely due to differences in their home language environment and decreased opportunities for back and forth communicative exchange. Intervention strategies that encourage reciprocal caregiver-child interactions may effectively promote young children's language development and enhance optimal language outcomes. The Filming Interactions to Nurture Development (FIND) program is a brief strength-based video-coaching intervention designed to promote increased back and forth ("serve and return") interactions between caregivers and their children. The current study used data from a randomized controlled trial (RCT) to examine the effectiveness of the FIND program in improving auditory comprehension and expressive communication skills among children from low-SES backgrounds. The current study used a pretest-posttest design to evaluate intervention effects from an RCT with 91 low-SES families. Families with children aged 4 to 36 months old (41.8% female) were randomly assigned to an active control or FIND intervention group. Children's auditory comprehension and expressive communication were assessed using the Preschool Language Scales, Fifth Edition (PLS-5) during both pre- and post-intervention sessions. Children in the FIND intervention group showed significantly increased expressive communication skills and a non-significant increase in auditory comprehension skills across the intervention period. In contrast, children in the active control group showed non-significant changes in expressive communication and a statistically significant decline in auditory comprehension abilities between pre- and post-intervention assessments. All analyses controlled for sex, age, and home language. This study provides preliminary evidence that the FIND intervention promotes the development of expressive and receptive language skills among young children in high-stress, low-SES environments.

Dissociating executive function and ADHD influences on reading ability in children with dyslexia.

Developmental dyslexia (DD) and attention-deficit/hyperactivity disorder (ADHD) are two of the most common neurodevelopmental disorders among school-age children. These disorders frequently co-occur, with up to 40-50% of children with one diagnosis meeting criteria for the other, and similar percentages of children with either DD or ADHD exhibiting impaired executive functions (EF). Although both ADHD and EF deficits are common in dyslexia, there is little evidence about how ADHD and EF deficits specifically influence the brain basis of reading difficulty in dyslexia, and whether the influences of ADHD and EF on dyslexia can be disentangled. The goal of the current study was to investigate, at both behavioral and brain levels, whether reading performance in individuals with dyslexia is more strongly associated with EF or with diagnostic status of comorbid ADHD. We examined reading abilities and EF in children (8-13 years old) with typical reading ability, DD only, or both DD + ADHD. Across both groups with dyslexia, impaired EF was associated with greater impairment on measures loading onto a reading fluency, but not a reading accuracy, factor. There were no significant differences between the DD and DD + ADHD groups on measures of reading fluency or reading accuracy. During functional magnetic resonance imaging (fMRI) while performing a rhyme-matching reading task requiring phonological awareness, typically developing readers showed greater left-hemisphere reading network activation than children with DD or DD + ADHD. Children with DD and DD + ADHD did not show differential activation, but DD children with unimpaired EF showed greater activation than those with impaired EF in reading-related areas. Thus, ADHD status alone had no measurable influence on reading performance or brain activation. Impaired EF in dyslexia, independent of ADHD status, was associated with greater deficits in reading fluency and greater reductions of activation in response to print in the typical left-hemisphere reading network.

Anxiety, Motivation, and Competence in Mathematics and Reading for Children With and Without Learning Difficulties.

Knowledge of the relations among learners' socio-emotional characteristics and competencies as they engage in mathematics and reading is limited, especially for children with academic difficulties. This study examined the relations between anxiety, motivation, and competence in mathematics and reading, within and across domains, in an academically-diverse set of 8-13-year-old learners (n = 146). To measure anxiety and motivation across domains, we paired existing measures of math anxiety and reading motivation with researcher-developed analogs for reading anxiety and math motivation. Participants completed standardized assessments of mathematics and reading, anxiety and motivation surveys for math and reading, and a measure of nonverbal cognitive ability. Results showed high internal consistency for all anxiety and motivation scales (Cronbach's alpha = 0.76-0.91). Pearson correlations showed that within and across domains, participants with higher competence had lower anxiety and higher motivation. Higher anxiety was also associated with lower motivation. Regression analyses showed that for both math and reading, within-domain motivation was a stronger predictor of competence than anxiety. There was a unidirectional across-domain relation: socio-emotional characteristics for reading predicted math competence, after accounting for nonverbal cognitive ability, age, gender, and within-domain anxiety and motivation. Results contribute to knowledge of the socio-emotional characteristics of children with and without learning difficulties in association with reading and math activities. Implications of a unidirectional socio-emotional link between the two domains can advance research and theory of the relations among socio-emotional characteristics and competence for academically-diverse learners.

Literacy-related skills among children after left or right hemispherectomy.

OBJECTIVE: Following hemispherectomy surgery, children's educational outcomes are of great importance but are understudied. The study goal was to investigate reading, language, and nonverbal cognitive skills in children obligatorily relying on a left versus right hemisphere using a cross-sectional design. METHODS: Participants (ages 6-18) who had undergone left hemispherectomy (LH; n = 10) or right hemispherectomy (RH; n = 14) completed standardized measures of reading, language, and nonverbal cognition. RESULTS: LH and RH groups were balanced for socioeconomic status, sex, and age. Both groups scored below the population mean across standardized measures (RH: -0.79 to -1.95 SDs; LH: -0.97 to -2.32 SDs). Compared to the LH group, the group retaining a functional left hemisphere (RH group) learned to read sooner (p = .011) despite no significant differences for surgery age, and scored higher on untimed real word and pseudoword reading measures (p < .05). Effect sizes were medium (r = 0.34-0.46) for the LH and RH comparison on measures of phonological awareness and both untimed and timed word and pseudoword reading. In examining the association between clinical variables and reading-related outcomes, younger age of post-hemispherectomy reading acquisition and shorter duration between seizure onset and hemispherectomy surgery were associated with higher standardized reading and language test scores (p < .05). SIGNIFICANCE: Investigations of psychoeducational skills in reading, language, and nonverbal cognition among children who have undergone hemispherectomy can offer important insights into compensatory potential for left and right hemispheres as well as inform educational programming for children following medical stabilization.

Reward-Sensitive Basal Ganglia Stabilize the Maintenance of Goal-Relevant Neural Patterns in Adolescents.

Maturation of basal ganglia (BG) and frontoparietal circuitry parallels developmental gains in working memory (WM). Neurobiological models posit that adult WM performance is enhanced by communication between reward-sensitive BG and frontoparietal regions, via increased stability in the maintenance of goal-relevant neural patterns. It is not known whether this reward-driven pattern stability mechanism may have a role in WM development. In 34 young adolescents (12.16-14.72 years old) undergoing fMRI, reward-sensitive BG regions were localized using an incentive processing task. WM-sensitive regions were localized using a delayed-response WM task. Functional connectivity analyses were used to examine the stability of goal-relevant functional connectivity patterns during WM delay periods between and within reward-sensitive BG and WM-sensitive frontoparietal regions. Analyses revealed that more stable goal-relevant connectivity patterns between reward-sensitive BG and WM-sensitive frontoparietal regions were associated with both greater adolescent age and WM ability. Computational lesion models also revealed that functional connections to WM-sensitive frontoparietal regions from reward-sensitive BG uniquely increased the stability of goal-relevant functional connectivity patterns within frontoparietal regions. Findings suggested (1) the extent to which goal-relevant communication patterns within reward-frontoparietal circuitry are maintained increases with adolescent development and WM ability and (2) communication from reward-sensitive BG to frontoparietal regions enhances the maintenance of goal-relevant neural patterns in adolescents' WM. The maturation of reward-driven stability of goal-relevant neural patterns may provide a putative mechanism for understanding the developmental enhancement of WM.

Early adversity, child neglect, and stress neurobiology: From observations of impact to empirical evaluations of mechanisms.

Research on the effects of early life adversity, and in particular on the absence of responsive caregiving, has shown long-term impacts on well-being and development. These investigations have been conducted both in human populations and in animal models. The work has demonstrated that neglect experienced in the early years can affect not only behavior but also neurobiological functioning. In particular, studies of children in the foster care system show convergence with research on children adopted following institutional rearing in terms of dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which produces the neuroendocrine hormone cortisol. The characteristic pattern that has been most commonly observed involves diminished diurnal cortisol production, particularly in terms of low levels of cortisol upon awakening. Notably, however, a number of evidence-based interventions for infant, toddler, and preschool-aged foster children have been shown to produce more typical patterns of cortisol production, in combination with improved behavioral, socioemotional, and foster care placement outcomes. In this paper, we review the literature on the effects of early disruptions in care on biobehavioral development, and summarize the results of the interventions for young foster children.

Use of volumetric capnography to identify pulmonary dysfunction in horses with and without clinically apparent recurrent airway obstruction.

OBJECTIVE: To investigate whether volumetric capnography indices could be used to differentiate between horses without recurrent airway obstruction (RAO) and horses with RAO that were in clinical remission or that had clinically apparent RAO. ANIMALS: 70 adult Swiss Warmblood horses (20 used for pleasure riding and 50 used for dressage or show jumping). PROCEDURE: Horses were allocated to 4 groups on the basis of history, clinical signs, results of endoscopy, and cytologic findings (group 1, 21 healthy horses; group 2, 22 horses with RAO that were in remission; group 3, 16 horses with mild RAO; group 4, 11 horses with exacerbated RAO). Expiratory volume and CO2 curves were recorded by use of a computerized ultrasonic spirometer. Volumetric capnograms were plotted, and derived indices were calculated. RESULTS: Dead-space volume (VD) was calculated by use of the Bohr equation (VD(Bohr)) and for physiologic VD (VD(phys)). Ratios for VD(Bohr) to expiratory tidal volume (VT) and VD(phys) to V(T) as well as an index of effective CO2 elimination were significantly different among groups of horses. Age and use of the horses also significantly affected volumetric capnography indices. CONCLUSIONS AND CLINICAL RELEVANCE: Ratios of VD(Bohr) to VT and VD(phys) to VT as well as an index of effective CO2 elimination were sufficiently sensitive measures to distinguish between healthy horses and horses with RAO in remission. To optimize the ability of volumetric capnography indices to differentiate among horses in heterogeneous populations, it is important to account for effects of age and specific use of the horses.

Role of NO in choroidal blood flow regulation during isometric exercise in healthy humans.

PURPOSE: Nitric oxide (NO) is an important regulator of basal choroidal blood flow. Animal experiments indicate that NO is also involved in choroidal blood flow regulation during changes in ocular perfusion pressure and inhibition of NO synthase (NOS) has been reported to shift choroidal pressure-flow curves to the right. The hypothesis for the study was that inhibition of NOS may influence choroidal blood flow during isometric exercise. METHODS: To test this hypothesis, a randomized, double-masked, placebo-controlled, three-way crossover study was performed in 12 healthy male volunteers. Subjects received on different study days intravenous infusions of N(G)-monomethyl-L-arginine (L-NMMA), phenylephrine, or placebo. During these infusion periods, subjects were asked to squat for 6 minutes. Choroidal blood flow was assessed with laser Doppler flowmetry, and ocular perfusion pressure (OPP) was calculated from mean arterial pressure and intraocular pressure. RESULTS: L-NMMA and phenylephrine increased resting OPP by 10% and 13%, respectively, but only L-NMMA reduced resting choroidal blood flow (-17%, P < 0.001). The relative increase in OPP during isometric exercise was comparable with all drugs administered. Isometric exercise increased choroidal blood flow during administration of placebo and phenylephrine, but not during administration of L-NMMA (P < 0.001 vs. placebo). CONCLUSIONS: These data indicate that NO plays an important role in the regulation of choroidal blood flow during isometric exercise.

Propranolol and atropine do not alter choroidal blood flow regulation during isometric exercise in healthy humans.

Recent studies indicate that the human choroid has a considerable capacity to keep blood flow constant despite exercise-induced increases in perfusion pressure. The mechanisms underlying this vasoconstrictor response remain unclear. We hypothesized that pharmacological modulation of the autonomic nervous system may alter the choroidal pressure/flow relationship during squatting. To test this hypothesis, we performed a randomized, double-masked, placebo-controlled, three-way crossover study in 15 healthy male volunteers. Subjects received, on different study days, intravenous infusions of the beta-adrenoceptor antagonist propranolol, the muscarinic receptor antagonist atropine, or placebo. During these infusions, subjects performed squatting for 6 min. Choroidal blood flow was assessed with laser Doppler flowmetry and ocular perfusion pressure (OPP) was calculated from mean arterial pressure and intraocular pressure. As expected, propranolol reduced basal pulse rate, whereas atropine increased pulse rate, indicating that the drugs were administered at systemically effective doses. None of the drugs altered the choroidal pressure/flow relationship during isometric exercise. These data indicate that the regulatory vasoconstrictor capacity of the choroid during exercise is not affected by systemic blockade of beta-adrenoceptors or muscarinic receptors.