Explicit Aiming Strategy Decreases the Differences in Visuomotor Adaptation between Children and Young Adults

ABSTRACT

We examined the visuomotor adaptation of children and adults with and without explicit aiming strategies. Younger children were slower and less smooth in visuomotor adaption than adults. Specifically, in the course of adaptation and re-adaptation, older children had better movement accuracy than adults, while their movement speed and smoothness were similar to those of the adults. Explicit aiming improved movement accuracy for all participants, but also facilitated movement smoothness for younger children. The contribution of explicit adjustment was greater for older children than for younger children. These results show the ongoing development of cognitive functions and movement experiences in children.     

Survival Differences between Adolescents/Young Adults and Children with B Precursor Acute Lymphoblastic Leukemia after Allogeneic Hematopoietic Cell Transplantation

Risk-adapted therapy has been the cornerstone of treatment for pediatric B precursor acute lymphoblastic leukemia (B-ALL). Recently, age ≥13 years at diagnosis has been identified as a very high-risk feature for chemotherapy treated pediatric patients with B-ALL. Whether age at time of transplantation is associated with poor outcomes in adolescents and young adults (AYA) is unknown. We hypothesized that AYA receiving allogeneic hematopoietic cell transplantation (allo-HCT) would have greater relapse and inferior survival compared with children age <13 years. We reviewed the outcomes in 136 consecutive patients (age 0-30 years) with B-ALL who underwent myeloablative allo-HCT at our institution, including 79 children age <13 years (58%) and 57 AYA age 13-30 years (42%). Overall survival at 5 years was significantly lower in the AYA group (hazard ratio, 1.74; 95% confidence interval [CI], 1.04-2.95; P = .03). In addition, the AYA patients had a greater risk of transplantation-related mortality at 1 year (hazard ratio, 2.23; 95% CI, 1.01-4.90; P = .05), but no difference in relapse (relative risk, 0.85; 95% CI, 0.41-1.76; P = .66). Based on this analysis, AYA patients undergoing allo-HCT for B-ALL have significantly inferior survival and greater transplantation-related mortality compared with children age <13 years, but no difference in relapse, suggesting that allo-HCT may overcome relapse in AYA. Further improvements in peritransplantation care are needed to limit complications in AYA patients.     

Individual Differences in Imagery Ability and Pavlovian Heart Rate Decelerative Conditioning

The purpose of the present experiment was to investigate the role of imagery ability in Pavlovian HR decelerative conditioning with a head-up to head-down body tilt as the US. From imagery theories of conditioning (e.g., King, 1973), it was hypothesized that the CR of subjects with good imagery abilities should be more similar to the UR than the CR of subjects with poor imagery abilities. The Betts QMI was used to select 32 subjects for their imagery ability. All subjects were treated identically during the course of the experimental session. Following 10 CS-US acquisition trials, the HR CR was assessed on a second-by-second basis during 9 CS-alone test trials. The data provided support for the hypothesis: the form of the CR was significantly different for the two groups. The CR of the good imagers remained below baseline for 10 sec (the duration of the actual tilt-US) while the CR of poor imagers returned to baseline within that period although the average magnitude of the CR for good and poor imagers did not differ. Implications of these data for human Pavlovian HR conditioning and applied (e.g., desensitization) psychophysiological research are discussed.     

Motor Imagery of the Unaffected Hand in Children With Spastic Hemiplegia

This study examined the ability of children with hemiplegia to perform motor imagery of their unaffected hand. Children (8–12 years) formed three groups—R-HEMI: right-sided hemiplegia, n?=?21; L-HEMI: left-sided hemiplegia, n?=?19; and Comparisons, n?=?21. We expected no group differences on a simple imagined grasping task, but the hemiplegia groups to perform atypically on an imagined pointing task. Results showed no group differences on the grasping task, while only the L-HEMI group performed atypically on the pointing task— the functional level of the children played a likely role in this finding. Children with hemiplegia can engage in motor imagery, although task complexity and functional level may have an impact.     

Individual Differences and Interventions for Infants and Young Children

This paper addresses the need of interveners to be responsiveto individual differences among infants and young children.Recent data are reviewed and implications for programming areexamined. The perspectives advanced argue for two kinds of considerationsof individual differences, the first program specific and thesecond child specific. The former may be most appropriate forinfants, whereas both are appropriate for somewhat older children.     

Source and Item Memory for Odors and Objects in Children and Young Adults

Recall and recognition memory for odors are poorer in children than in adolescents. In addition, children perform worse than young adults on source memory tasks using visual and auditory stimuli. However, source memory for odor stimuli has not been examined in children. This study investigated source and item memory for odors and objects in children (7–10 years old) and young adults (18–24 years old). During the study phase, 1 male and 1 female experimenter (sources) randomly presented either 16 odors or 16 objects to the participant. Presentation alternated between sources so that each source presented 8 stimuli. Once the 16 stimuli were presented, the sources exited and a third experimenter began the test phase. To assess item recognition memory, a stimulus from the study phase and a novel stimulus were presented to the participant who was asked to choose the stimulus presented during the study phase. Source memory was assessed with the 8 stimuli from the study phase not used in the item memory task. The experimenter presented a stimulus and asked whether the male or female experimenter had presented the stimulus during the study phase. Results indicate that difference scores between item and source memory for odors were significantly larger for children than for young adults, indicating poorer source memory for children than adults. Difference scores for objects did not distinguish between groups. It has been suggested that the frontal lobes play a critical role in source memory and odor memory—a brain region that continues to develop into adolescence. Poor performance among children on the source memory task for odors may be due in part to immaturity of the frontal lobes.     

Revisiting the Accuracy Hypothesis in Families of Young Children With Conduct Problems

Revisited the accuracy hypothesis in an examination of the relation between maternal depressive symptomatology and child conduct problems. All data were gathered as part of the pretreatment assessment in an outcome study of families with clinic-referred children with conduct problems (age 3 to 6). The mothers varied in their depressive symptomatology, from not at all symptomatic to severely symptomatic. Correlations indicated that with increasing depressive symptomatology, mothers (N = 97) displayed a higher rate of physical negative behaviors towards their child and reported more child conduct problems. Regression analyses revealed that at the lowest levels of maternal depressive symptomatology there was a discrepancy between mothers' reports of child behavior problems and child deviant behaviors observed during mother-child interaction. In contrast, at higher levels of depression, mothers' reports of child behavior were consistent with laboratory observations of their child's behavior. These findings provide evidence to support the accuracy hypothesis in reference to mothers who display a high degree of depressive symptomatology, but the results also call into question the validity of maternal report in families with children with conduct problems.     

Assessment of Hot and Cool Executive Function in Young Children: Age-Related Changes and Individual Differences

Although executive function (EF) is often considered a domain-general cognitive function, a distinction has been made between the "cool" cognitive aspects of EF more associated with dorsolateral regions of prefrontal cortex and the "hot" affective aspects more associated with ventral and medial regions (Zelazo & M?ller, 2002). Assessments of EF in children have focused almost exclusively on cool EF. In this study, EF was assessed in 3- to 5-year-old children using 2 putative measures of cool EF (Self-Ordered Pointing and Dimensional Change Card Sort) and 2 putative measures of hot EF (Children's Gambling Task and Delay of Gratification). Findings confirmed that performance on both types of task develops during the preschool period. However, the measures of hot and cool EF showed different patterns of relations with each other and with measures of general intellectual function and temperament. These differences provide preliminary evidence that hot and cool EF are indeed distinct, and they encourage further research on the development of hot EF.     

Cardiac and Blink Reflex Concomitants of Attentional Selectivity: A Comparison of Adults and Young Children

Selective attention, often considered less efficient in young children, was examined in adults and 5-yr-olds using a new, startle-probe technique. To investigate the allocation of preparatory attention at early stages of processing, we examined the modification of the startle blink reflex to irrelevant acoustic probes presented within the warning interval (WI) of a simple reaction time task. Attention was directed away from the acoustic probes and toward a vibrotactile GO signal during the 6-s WI. Heart rate decelerated prior to the GO signal in both children and adults, implying increased attention. The two groups showed opposite patterns of blink modification, however. In adults, startle blink to the WI probes was increasingly attenuated as the GO signal approached, suggesting a selective pattern of attentional allocation. In contrast, blink amplitude increased linearly across probe positions in children, implying that preparatory attention was allocated to a wider range of sensory input.     

关于幼儿穿衣重量和运动能力的研究

以中国T市幼儿园318名幼儿为对象、在2月中旬调查和测定了穿衣重量以及户外游戏时间、运动能力。所得结果与日本幼儿（荒木等1982）进行了比较。在大致相同的室外气温、生活室温和放园回家后的自由时间的条件下、与中国幼儿相比,日本幼儿穿衣薄少、户外游戏时间长。而且,日本幼儿的运动能力优于中国幼儿。根据此测定结果可以认为穿衣重量对幼儿的运动能力有着一定影响、薄着有利于提高幼儿的耐寒暑能力和运动能力。     

Prevention and Treatment of Acute Graft-versus-Host Disease in Children,Adolescents, and Young Adults

Acute graft-versus-host disease (GVHD) continues to be a major cause of morbidity and mortality after allogeneic hematopoietic cell transplant (HCT) in pediatric patients (ie, children and adolescent and young adults) and limits broader application of the therapy. Pediatric HCT patients have faced major obstacles to access clinical trials that test new agents for GVHD prevention and treatment. According to a recent search, only 6 clinical trials of interventions for prevention or treatment of acute GVHD were conducted specifically in pediatric patients in the United States over the past decade, with 8 internationally. In this review, we summarize the studies that were performed and specifically enrolled and reported on pediatric patients after allogeneic HCT and provide a listing of studies currently under way.     

Gender Differences in Comorbidities and Attitudes Regarding Weight Control among Young Adults with Obesity in Korea

IntroductionObesity in young adulthood increases the risk for premature death, and the prevalence of obesity rapidly increasing among young adults, particularly in young men. We evaluated the gender differences in accompanying comorbidities and attitudes regarding weight control among young Korean adults with obesity.Materials and MethodsWe analyzed 2,050 young adults with obesity (1,325 men and 725 women) in the 7th KNHANES (2016–2018) aged 19–44 years, with body mass indexes (BMIs) ≥25.0 kg/m². The odds ratios (ORs) and 95% confidence intervals (CIs) for poor lifestyle factors and accompanying illnesses as well as self-perceived weight status, weight control efforts, and weight control strategies in men compared to those in women were calculated by multivariate logistic regression analysis.ResultsThe mean BMIs and waist circumferences were 28.2 ± 0.1 kg/m² and 93.6 ± 0.2 cm and 28.6 ± 0.1 kg/m² and 88.7 ± 0.4 cm, in men and women, respectively. The ORs and 95% CIs for abdominal obesity (1.52, 1.11–2.07), hypertension (3.11, 2.20–4.40), hypercholesterolemia (1.45, 1.09–1.93), hypertriglyceridemia (3.37, 2.38–4.78), and elevated alanine transaminase concentration (6.53, 4.56–9.36) were higher in young men compared to those in young women. Despite the higher prevalences of comorbid conditions, the odds of inappropriate weight perception (8.13, 4.17–15.86), lack of weight control efforts (2.20, 1.71–2.84), lack of diet therapy (1.56, 1.13–2.16), lack of pharmacotherapy (13.27, 6.82–25.79), heavy drinking (1.32, 1.02–1.72), current smoking (6.92, 5.00–9.59), and frequent eating out (4.38, 3.35–5.71) were higher among men. However, the odds of not engaging in exercise (0.48, 0.35–0.64) were lower among men compared to that in women.DiscussionDespite their higher prevalences of comorbidities, appropriate weight perception and weight control efforts are insufficient in young men with obesity. These gender differences should be considered to provide tailored programs for weight reduction in young adults with obesity.     

Sleep Contribution to Motor Memory Consolidation: A Motor Imagery Study

Study Objectives:

Sleep is known to enhance performance following physical practice (PP) of a new sequence of movements. Apart from a pilot study, it is still unknown whether a similar sleep-dependent consolidation effect can be observed following motor imagery (MI) and whether this mnemonic process is related to MI speed.

Design:

Counterbalanced within-subject design.

Setting:

The laboratory.

Participants:

Thirty-two participants.

Interventions:

PP, real-time MI, fast MI, and NoSleep (control) groups.

Measurements and Results:

Subjects practiced an explicitly known sequence of finger movements, and were assigned to PP, real-time MI, or fast MI, in which they intentionally imagined the sequence at a faster pace. A NoSleep group subjected to real-time MI, but without any intervening sleep, was also tested. Performance was evaluated before practice, as well as prior to, and after a night of sleep or a similar time interval during the daytime. Compared with the NoSleep group, the results revealed offline gains in performance after sleep in the PP, real-time MI, and fast MI groups. There was no correlation between a measure of underestimation of the time to imagine the motor sequence and the actual speed gains after sleep, neither between the ease/difficulty to form mental images and performance gains.

Conclusions:

These results provide evidence that sleep contributes to the consolidation of motor sequence learning acquired through MI and further suggests that offline delayed gains are not related to the MI content per se. They extend our previous findings and strongly confirm that performance enhancement following MI is sleep dependent.

Citation:

Debarnot U; Creveaux T; Collet C; Doyon J; Guillot A. Sleep contribution to motor memory consolidation: a motor imagery study. SLEEP 2009;32(12):1559-1565.     

Tryptophan and Sleep in Young Adults

Oral administration of L-tryptophan increases brain serotonin levels by following normal 5-hydroxyindole pathways (Moir & Eccleston, 1968). Since recent studies (Jouvet, 1969) suggest that serotonin is important in controlling sleep mechanisms, L-tryptophan provides a useful method for investigating further the role of serotonin in sleep. In two experiments, EEG sleep patterns from 21 young adult males were examined following moderate (7.5 g) and high (12 g) oral doses of L-tryptophan. Moderate doses produced sedative effects (reports of extreme drowsiness and reduced time awake) accompanied by increased slow-wave sleep. The only effects on REM parameters were a trend (in some Ss) to early onset of stage REM, a small decrease in the period of the REM cycle, and decreased density of rapid eye movements. With the high dose, Ss again reported extreme drowsiness, and time to sleep onset was decreased. However, changes in SW sleep and waking time appeared only as non-significant trends. In the high-dose group, percent of REM sleep was markedly increased, due to early onset of stage REM and to increased duration of REM episodes during the second half of the night. EEG sleep patterns on recovery nights following large doses of tryptophan were not systematically different from baseline nights. These results indicate that the changes in sleep patterns produced by L-tryptophan, presumably acting through 5-hydroxyindole pathways, are dependent on dose. The findings are consistent with the idea that serotonin, or one of its metabolites, is involved in the mechanisms controlling both SW and REM sleep.     

Outcomes after Second Hematopoietic Cell Transplantation in Children and Young Adults with Relapsed Acute Leukemia

Children with acute leukemia who relapse after hematopoietic cell transplantation (HCT) have few therapeutic options. We studied 251 children and young adults with acute myelogenous or lymphoblastic leukemia who underwent a second HCT for relapse after their first HCT. The median age at second HCT was 11 years, and the median interval between first and second HCT was 17 months. Most of the patients (n?=?187; 75%) were in remission, received a myeloablative conditioning regimen (n?=?157; 63%), and underwent unrelated donor HCT (n?=?230; 92%). The 2-year probability of leukemia-free survival (LFS) was 33% after transplantation in patients in remission, compared with 19% after transplantation in patients not in remission (P?=?.02). The corresponding 8-year probabilities were 24% and 10% (P?=?.003). A higher rate of relapse contributed to the difference in LFS. The 2-year probability of relapse after transplantation was 42% in patients in remission and 56% in those in relapse (P?=?.05). The corresponding 8-year probabilities were 49% and 64% (P?=?.04). These data extend the findings of others showing that patients with a low disease burden are more likely to benefit from a second transplantation. Late relapse led to a 10% decrement in LFS beyond the second year after second HCT. This differs from first HCT, in which most relapses occur within 2 years after HCT.     

Single-Unit versus Double-Unit Umbilical Cord Blood Transplantation in Children and Young Adults with Residual Leukemic Disease

We previously reported in a French prospective randomized study that transplantation of 2 unrelated cord blood (UCB) units instead of 1 unit does not decrease the risk of transplantation failure but may enhance alloreactivity. Here we evaluated the influence of pretransplantation minimal residual disease (MRD) on leukemia relapse and survival after single- versus double-UCB transplantation (UCBT). Among 137 children and young adults who underwent UCBT in this randomized study, 115 had available data on MRD assessment done immediately before initiation of the pretransplantation conditioning regimen. MRD was considered positive at a level of ≥10^?4, which was the case of 43 out of 115 patients. Overall, the mean 3-year survival probability was 69.1 ± 4.4%, and it was not significantly influenced by the MRD level: 70.7 ± 5.4% in MRD-negative (<10^?4) patients (n?=?72), 71.1 ± 9.4% in MRD-positive patients with 10^?4 ≤ MRD <10^?3 (n?=?26) and 58.8 ± 11.9% in MRD-positive patients with ≥10^?3 (n?=?17). In the MRD-positive group, the mean risk of relapse was significantly lower in the double-UCBT arm compared with the single-UCBT arm (10.5 ± 7.2% versus 41.7 ± 10.4%; P?=?.025) leading to a higher mean 3-year survival rate (82.6 ± 9.3% versus 53.6 ± 10.3%; P?=?.031). This difference was observed only in patients who had not received antithymocyte globulin during their conditioning regimen. In the MRD-negative group, there was no differencebetween the single- and the double-UCBT arms. We conclude that even in cases of positive pretransplantation MRD, UCBT in children and young adults with acute leukemia yields a high cure rate, and that a double-unit strategy may enhance the graft-versus-leukemia effect and survival in these patients.     

Comparison of Event-Related Potentials of Young Children and Adults in a Visual Recognition and Word Reading Task

An experiment is described in which event-related potentials (ERPs) of a group of young children were compared with ERPs of a group of young adults. Both groups were required to perform a simple word-reading task and a picture-recognition task. Principal components analyses (PCAs) were performed on the averaged ERPs in two different ways: a) separately for each of four combinations of tasks and age groups, and b) separately for each age group (pooled across tasks). The results demonstrated that ERP components of children and adults differed both qualitatively and quantitatively. First, children's ERPs were characterized by a long-latency negative component (N500) and a slow positive wave (SW) component, and adults’ ERPs were characterized by two late positive components (P340 and SW respectively). Second, both children and adults showed an earlier positive component that varied in peak latency between 280 ms for children and 240 ms for adults. In addition, adults showed a marked increase in SW positivity in the word-reading task as compared with the picture-recognition task, while task effects were less manifest in the components of children. These results support the notion that children and adults differed both in speed as well as in their mode of processing under the different task requirements.