Assisted Cycle Therapy (ACT) Improved Self-Efficacy and Exercise Perception in Middle-Age Adults with Down Syndrome.

Alzheimer's disease is prevalent in persons with Down syndrome (DS) as early as their 30s and presents as decreased social interaction, coordination, and physical activity. Therefore, changing attitudes and beliefs about exercise is key to increasing motivation for physical activity especially in middle-age adults with DS. The aim of this study was to examine the effects of Assisted Cycle Therapy (ACT) on self-efficacy and exercise perception in middle-age adults with Down syndrome (DS) following an exercise intervention three times a week for 8 weeks. Twelve participants were in the ACT group in which a motor assisted their cycling to be performed at least 30% faster than voluntary cycling (VC), 10 participants were in the voluntary cycling group, and two participants were in the no cycling (NC) group. The results showed that both exercise groups (i.e., ACT and VC) improved in their self-efficacy after the 8-week intervention. In addition, exercise perception improved following ACT, but not VC or NC. Our results are discussed with respect to their future implications for exercise in the DS population. The results can be attributed to differences in effort required by each intervention group as well as the neurotrophic factors that occur when muscle contractions create synaptic connections resulting in improvement in cognition and feelings of satisfaction.

Delay of gaze fixation during reaching movement with the non-dominant hand to a distant target.

The present study examined the effects of hand and task difficulty on eye-hand coordination related to gaze fixation behavior (i.e., fixating a gaze to the target until reach completion) in single reaching movements. Twenty right-handed young adults made reaches on a digitizer, while looking at a visual target and feedback of hand movements on a computer monitor. Task difficulty was altered by having three target distances. In a small portion of trials, visual feedback was randomly removed at the target presentation. The effect of a moderate amount of practice was also examined using a randomized trial schedule across target-distance and visual-feedback conditions in each hand. The results showed that the gaze distances covered during the early reaching phase were reduced, and the gaze fixation to the target was delayed when reaches were performed with the left hand and when the target distance increased. These results suggest that when the use of the non-dominant hand or an increased task difficulty reduces the predictability of hand movements and its sensory consequences, eye-hand coordination is modified to enhance visual monitoring of the reach progress prior to gaze fixation. The randomized practice facilitated this process. Nevertheless, variability of reach trajectory was more increased without visual feedback for right-hand reaches, indicating that control of the dominant arm integrates more visual feedback information during reaches. These results together suggest that the earlier gaze fixation and greater integration of visual feedback during right-hand reaches contribute to the faster and more accurate performance in the final reaching phase.

Determinants of fine manual dexterity in adolescents and young adults with Down's syndrome.

BACKGROUND: To date, numbers of studies have indicated the important role of fine manual dexterity in typical and special populations. However, the relevant studies in Down's syndrome (DS) population is still limited. The purpose of this study was to investigate the determinants of manual dexterity in adolescents and young adults with DS. METHODS: Thirty participants with DS (22 males, 8 females, aged 13-31) were screened by anthropometric variables (i.e. sex, chronological age, verbal intelligence, body mass index), levels of physical activity, and sleep disorders, and were administered the Purdue Pegboard Test and the Choice Reaction Time Test. Measures of correlation, t-test and multiple regression model were used for data analysis. RESULTS: It was indicated that sex and sleep-related disorders during the day explained 37.2% of the variance in the performance of the Purdue Pegboard Test. The additional of 9.7% can be explained the variance by adding reaction time test performance. Verbal intelligence had the negatively relation with the performance of non-Dominant Hand and Bimanual subtests of the Purdue Pegboard Test. CONCLUSION: This study suggested that sex, sleep disorder, and neuromotor function may be the important determinants of fine manual dexterity performance in adolescents and young adults with DS. In addition, the level of intelligence might also exert the effect on fine motor development in this population. In order to design effective interventions and optimize manual performance in individuals with DS, these possible determinants should be considered. Future research should be replicated with large sample size, different age groups, and validated measures of finger size, physical activity and sleep behaviors.

Telomere Length and Autism Spectrum Disorder Within the Family: Relationships With Cognition and Sensory Symptoms.

Telomeres are repetitive noncoding deoxynucleotide sequences that cap chromosomes to protect DNA. Telomere length (TL) is affected by both genetic and environmental factors, and shortening of telomeres is associated with multiple neuropsychiatric disorders, early life stress, and age-related cognitive dysfunction. Two previous studies associated shorter TL with autism spectrum disorder (ASD). We aimed to replicate this finding, describe TL in unaffected siblings, and explore novel relationships with symptoms and cognitive function in families with ASD. Participants were 212 male children and adolescents ages 1-17 years (86 with ASD, 57 unaffected siblings, and 69 typically developing [TD]) and 64 parents. TL was measured from blood leukocytes with quantitative real-time polymerase chain reaction and results are expressed by relative ratios with a single copy gene. We replicated that children and adolescents with ASD have shorter TL, compared to TD, and show that unaffected siblings have TL in between those of TD and ASD. We present novel associations between TL and sensory symptoms in ASD. Finally, we demonstrate cognitive functions, but not autistic traits, are related to TL in parents of children with ASD. Cognitive function and TL were not related in children and adolescents. As the third replication, our results elicit confidence in the finding that ASD is associated with shorter TL. Our novel sensory investigation suggests that shortened TL may be a biological mechanism of sensory symptoms in ASD. Furthermore, results highlight the need to better understand relationships between cognition, aging, and TL in families with ASD. Autism Res 2020, 13: 1094-1101. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Telomeres cap chromosomes to protect DNA. They progressively shorten as people age and are related to health outcomes. We replicated previous findings that children and adolescents with autism spectrum disorder (ASD) have shorter telomeres, compared to typically developing (TD), and show that unaffected siblings have telomere length (TL) in between those of TD and ASD. We find shortened TL is related to more severe sensory symptoms. This may mean families with ASD, especially those with elevated sensory symptoms, are at risk for worse age-related health outcomes.

Improvements in manual dexterity relate to improvements in cognitive planning after assisted cycling therapy (ACT) in adolescents with down syndrome.

We have previously reported beneficial effects of acute (i.e., single session) Assisted Cycling Therapy (ACT) on manual dexterity and cognitive planning ability in adolescents with Down syndrome (DS). In the present study, we report the chronic effects of eight weeks of ACT, voluntary cycling (VC), and no cycling (NC), on the same measures in adolescents with DS. Participants completed 8 weeks of ACT, VC, or NC. Those in the ACT and VC groups completed 30min sessions three times per week on a stationary bicycle. During ACT, the mechanical motor of the bicycle augmented the cadence to a rate which was on average 79% faster than the voluntary cadence. During VC, the participants pedaled at a self-selected rate. Unimanual dexterity scores as measured with the Purdue Pegboard test (PPT) improved significantly more for the ACT and VC groups compared to the NC group. ACT lead to greater improvements than VC and NC in the assembly sub-test, which is a task that requires more advanced temporal and spatial processing. The ACT group improved significantly more than the VC group and non-significantly more than the NC group in cognitive planning ability as measured by the Tower of London test (ToL). There were also significant correlations between the assembly subtest of the PPT and all measures of the ToL. These correlations were stronger during post-testing than pre-testing. Pre-post changes in the combined PPT score and ToL number of correct moves correlated positively in the ACT group. These results support the efficacy of the salutary effects of ACT on global fine motor function and executive function in DS. Additionally, the performance on complex bimanual dexterity tasks appears to be related to the capacity of cognitive planning ability. This research has important implications for persons with movement deficits that affect activities of daily living.

Acute bouts of assisted cycling improves cognitive and upper extremity movement functions in adolescents with Down syndrome.

The aim of this study was to examine the effectiveness of 2 modes of exercise on cognitive and upper extremity movement functioning in adolescents with Down syndrome (DS). Nine participants randomly completed 3 interventions over 3 consecutive weeks. The interventions were: (a) voluntary cycling (VC), in which participants cycled at their self-selected pedaling rate; (b) assisted cycling (AC), in which the participants' voluntary pedaling rates were augmented with a motor to ensure the maintenance of 80 rpm; and (c) no cycling (NC), in which the participants sat and listened to music. Manual dexterity improved after AC, but not after VC or NC. Measures of cognitive function, including reaction time and cognitive planning, also improved after AC, but not after the other interventions. Future research will try to uncover the mechanisms involved in the behavioral improvements found after an acute bout of assisted cycling in adolescents with DS.

Unimanual and bimanual continuous movements benefit from visual instructions in persons with Down syndrome.

The authors' aim was to understand how persons with Down syndrome (DS) perform different tasks and to assess if there were any differences in performance based on the type of instructions. This is important because of neurological differences in persons with DS and neurological demands for performing different types of tasks. Twenty right-handed participants with DS, 20 chronological age-matched (CA), and 20 mental age-matched (MA) performed unimanual, bimanual, discrete, and continuous drumming following visual, auditory, and verbal instructions. Overall, discrete drumming was performed with shorter movement times than continuous drumming and unimanual drumming was performed with shorter movement amplitude than bimanual drumming. With respect to instructions, persons with DS performed with smaller amplitudes, thus more efficient movements, following the visual instructions than auditory and verbal instructions for all types of tasks, whereas CA performed similarly with all instructions and MA performed with smaller amplitudes with visual instructions than auditory instructions. These results suggest that visual instruction provides the best information for people with DS to aid in performance of many different types of movements.

Auditory instructional cues benefit unimanual and bimanual drawing in Parkinson's disease patients.

The present study investigated performance of unimanual and bimanual anti-phase and in-phase upper limb line drawing using three different types of cues. Fifteen Parkinson's disease (PD) patients, 15 elderly, and 15 young adults drew lines away from and towards their body on a tabletop every 1000 ms for 30 s under three different cueing conditions: (1) verbal ('up', 'down'); (2) auditory (high tone, low tone); (3) visual (target line switched from top to bottom). PD patients had larger and more variable amplitudes which may be related to the finding that they also produced more curvilinear movements than young and elderly adults. Consistent with previous research, when compared to the elderly and young adult group PD patients produced a mean relative phase which deviated more from the instructed coordination modes and they showed larger variability of relative phase in bimanual coordination, especially in anti-phase conditions. For all groups, auditory and verbal cues resulted in lower coefficient of variance of cycle time, lower variability of amplitude and lower variability of relative phase than visual cues. The benefit of auditory cues may be related to the timing nature of the task or factors related to the auditory cues (e.g., reduced attentional demands, more kinesthetic focus).

Variability in head movement during gait transitions.

Predictions from a model of coupled oscillators, which was based on stationary interlimb coordination, were examined in locomotor intralimb coordination. The present study measured head linear and angular accelerations and coordination relationships of the head and torso, e.g., using relative phase measures, during walking and running on a treadmill. Head linear acceleration increased from walking to running and decreased from running to walking, and head pitch/torso pitch relative phase decreased from walking to running and increased from running to walking. No other measures were significantly different for either walking or running (head angular acceleration, mean head vertical displacement/head pitch relative phase, SD head vertical displacement/head pitch, and SD head pitch/torso pitch). This information will aid further understanding of the many aspects involved in locomotor coordination.