Differences in means-end exploration between infants at risk for autism and typically developing infants in the first 15 months of life.

Our study compared means-end exploration in infants at risk (AR) for autism and typically developing (TD) infants using a nested box paradigm. Sixteen AR and 16 TD infants were observed at 9, 12, and 15 months with follow-up at 18 and 24 months. We collected video data on three tasks involving retrieval of a small toy by opening (a) an opaque box, (b) a transparent box, and (c) two nested boxes. Dependent variables included hand bias, time to completion, bilateral hand use, problem-solving strategies used, and tester assistance required. There were no group differences in terms of hand biases. Compared to TD infants, AR infants had lower bilateral hand use, poor problem solving skills, and required greater assistance. Both groups demonstrated age-related improvements in motor and cognitive skills. Means-end exploration provides a window into the bilateral coordination and motor planning/problem-solving abilities of young infants at risk for autism. Lastly, object retrieval tasks could serve as important learning contexts for at-risk infants.

Effect of interactions between a child and a robot on the imitation and praxis performance of typically devloping children and a child with autism: a preliminary study.

Interactions between a robot and a child (robot-child interactions) provide a unique context to engage children in whole body movements through a reciprocal imitation game. The effects of a novel, 8-session, robot-child interaction protocol on the imitation and praxis skills of 15 typically developing children and one child with autism between 4 and 7 years of age were examined. A quasi-experimental observational comparison of pretest and posttest performance was conducted. A task-specific robot imitation test and a standardized praxis measure were coded for changes in imitation and praxis errors at pretest and posttest. All children showed improvements in task-specific imitation and generalized praxis. Interpretation is limited by the lack of a control group. These findings serve as a foundation for further investigation of robot-child interactions as a potential training tool for children with dyspraxia.

Fewer children with autism spectrum disorder with motor challenges receive physical and recreational therapies compared to standard therapies: A SPARK data set analysis.

LAY ABSTRACT: There are clear disparities in motor services provided to children with autism spectrum disorder (physical and recreational therapies) compared to their standard therapies (speech-language and occupational therapies). Children with autism spectrum disorder need greater access to and funding for motor services (physical and recreational therapies) and physical activity programs. Movement experts including PTs, adapted physical educators, and community exercise/sports coaches/professionals need basic, specialized, and continuing education training to meet the needs of children and adults with autism spectrum disorder not only for providing early developmental and school-based services but also for ensuring appropriate built environments and providing general physical therapy/adapted physical education services as well as physical activity programs.

Autism-Related Differences in Cortical Activation When Observing, Producing, and Imitating Communicative Gestures: An fNIRS Study.

Children with autism spectrum disorder (ASD) have difficulties in gestural communication during social interactions. However, the neural mechanisms involved in naturalistic gestural communication remain poorly understood. In this study, cortical activation patterns associated with gestural communication were examined in thirty-two children with and without ASD (mean age: 11.0 years, SE: 0.6 years). Functional near-infrared spectroscopy (fNIRS) was used to record cortical activation while children produced, observed, or imitated communicative gestures. Children with ASD demonstrated more spatial and temporal errors when performing and imitating communicative gestures. Although both typically developing (TD) children and children with ASD showed left-lateralized cortical activation during gesture production, children with ASD showed hyperactivation in the middle/inferior frontal gyrus (MIFG) during observation and imitation, and hypoactivation in the middle/superior temporal gyrus (MSTG) during gesture production compared to their TD peers. More importantly, children with ASD exhibited greater MSTG activation during imitation than during gesture production, suggesting that imitation could be an effective intervention strategy to engage cortical regions crucial for processing and producing gestures. Our study provides valuable insights into the neural mechanisms underlying gestural communication difficulties in ASD, while also identifying potential neurobiomarkers that could serve as objective measures for evaluating intervention effectiveness in children with ASD.

A further study of relations between motor impairment and social communication, cognitive, language, functional impairments, and repetitive behavior severity in children with ASD using the SPARK study dataset.

Motor impairments are pervasive and persistent in children with autism spectrum disorder (ASD) throughout childhood and adolescence. Based on recent studies examining motor impairments in children with ASD between 5 and 15 years (i.e., SPARK study sample), 87-88% of this population is at-risk for a motor impairment, these problems persisted until 15 years, and related to their core (social communication skills and repetitive behaviors [RBs]) and comorbid (language, cognitive, and functional) impairments. Persistent motor impairments extending into adolescence/adulthood could negatively impact their independent daily living skills, physical fitness/activity levels, and physical/mental health. While multiple studies have examined relations between motor dimensions and core/comorbid impairments in young children with ASD, few studies have examined such relations in school-age children/adolescents with ASD. This paper conducts a further multidimensional study of which motor domains (i.e., gross-motor including visuo-motor or multilimb coordination/planning, fine motor [FM] or general coordination [GC] skills) best distinguish subgroups of school-age children/adolescents with ASD and help predict core and comorbid impairments after accounting for age and sex. Visuomotor, FM and certain GC skills were better at explaining variations in/predicting social communication impairments whereas FM skills were slightly better at explaining variations in/predicting RB severity. Multilimb coordination/planning and FM skills explained variations in/predicted cognitive delays whereas visuomotor and FM skills explained variations in and better predicted language delays. All three motor dimensions explained variations in/predicted functional delays. This study provides further evidence for inclusion of motor impairments within the ASD definition (criteria or specifiers). LAY SUMMARY: Gross-motor skills were related to social communication and functional delays of children with ASD (visuomotor skills related to language delays and multilimb coordination/planning skills related to cognitive delays). Fine-motor skills were related to repetitive behavior severity, language, cognitive, and functional delays in ASD. Diagnosticians should recommend systematic motor screening, further evaluations, and treatments for children at-risk for and diagnosed with ASD. Motor advocacy and enhanced public/clinical community awareness is needed to fulfill the unmet motor needs of children with ASD.

Motor Impairment Increases in Children With Autism Spectrum Disorder as a Function of Social Communication, Cognitive and Functional Impairment, Repetitive Behavior Severity, and Comorbid Diagnoses: A SPARK Study Report.

Eighty-seven percent of a large sample of children with autism spectrum disorder (ASD) are at risk for motor impairment (Bhat, Physical Therapy, 2020, 100, 633-644). In spite of the high prevalence for motor impairment in children with ASD, it is not considered among the diagnostic criteria or specifiers within DSM-V. In this article, we analyzed the SPARK study dataset (n = 13,887) to examine associations between risk for motor impairment using the Developmental Coordination Disorder-Questionnaire (DCD-Q), social communication impairment using the Social Communication Questionnaire (SCQ), repetitive behavior severity using the Repetitive Behaviors Scale - Revised (RBS-R), and parent-reported categories of cognitive, functional, and language impairments. Upon including children with ASD with cognitive impairments, 88.2% of the SPARK sample was at risk for motor impairment. The relative risk ratio for motor impairment in children with ASD was 22.2 times greater compared to the general population and that risk further increased up to 6.2 with increasing social communication (5.7), functional (6.2), cognitive (3.8), and language (1.6) impairments as well as repetitive behavior severity (5.0). Additionally, the magnitude of risk for motor impairment (fine- and gross-motor) increased with increasing severity of all impairment types with medium to large effects. These findings highlight the multisystem nature of ASD, the need to recognize motor impairments as one of the diagnostic criteria or specifiers for ASD, and the need for appropriate motor screening and assessment of children with ASD. Interventions must address not only the social communication and cognitive/behavioral challenges of children with ASD but also their motor function and participation. LAY ABSTRACT: Eighty-eight percent of the SPARK sample of children with ASD were at risk for motor impairment. The relative risk for motor impairment was 22.2 times greater in children with ASD compared to the general population and the risk increased with more social communication, repetitive behavior, cognitive, and functional impairment. It is important to recognize motor impairments as one of the diagnostic criteria or specifiers for ASD and there is a need to administer appropriate motor screening, assessment, and interventions in children with ASD.

Effects of Creative Movement Therapies on Social Communication, Behavioral-Affective, Sensorimotor, Cognitive, and Functional Participation Skills of Individuals With Autism Spectrum Disorder: A Systematic Review.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder affecting multiple developmental domains including social communication, behavioral-affective, sensorimotor, and cognitive systems. There is growing evidence for the use of holistic, whole-body, Creative Movement Therapies (CMT) such as music, dance, yoga, theater, and martial arts in addressing the multisystem impairments in ASD. We conducted a comprehensive quantitative and qualitative review of the evidence to date on the effects of CMT on multiple systems in individuals with ASD. The strongest evidence, both in terms of quantity and quality, exists for music and martial arts-based interventions followed by yoga and theater, with very limited research on dance-based approaches. Our review of 72 studies (N = 1,939 participants) across participants with ASD ranging from 3 to 65 years of age suggests that at present there is consistent evidence from high quality studies for small-to-large sized improvements in social communication skills following music and martial arts therapies and medium-to-large improvements in motor and cognitive skills following yoga and martial arts training, with insufficient evidence to date for gains in affective, sensory, and functional participation domains following CMT. Although promising, our review serves as a call for more rigorous high-quality research to assess the multisystem effects of CMT in ASD. Based on the existing literature, we discuss implications of our findings for autism researchers and also provide evidence-based guidelines for clinicians to incorporate CMT approaches in their plan of care for individuals with ASD.

Developmental Differences in Cortical Activation During Action Observation, Action Execution and Interpersonal Synchrony: An fNIRS Study.

Interpersonal synchrony (IPS) is an important everyday behavior influencing social cognitive development; however, few studies have investigated the developmental differences and underlying neural mechanisms of IPS. functional near-infrared spectroscopy (fNIRS) is a novel neuroimaging tool that allows the study of cortical activation in the presence of natural movements. Using fNIRS, we compared cortical activation patterns between children and adults during action observation, execution, and IPS. Seventeen school-age children and 15 adults completed a reach to cleanup task while we obtained cortical activation data from bilateral inferior frontal gyrus (IFG), superior temporal sulcus (STS), and inferior parietal lobes (IPL). Children showed lower spatial and temporal accuracy during IPS compared to adults (i.e., spatial synchrony scores (Mean ± SE) in children: 2.67 ± 0.08 and adults: 2.85 ± 0.06; temporal synchrony scores (Mean ± SE) in children: 2.74 ± 0.06 and adults: 2.88 ± 0.05). For both groups, the STS regions were more activated during action observation, while the IFG and STS were more activated during action execution and IPS. The IPS condition involved more right-sided activation compared to action execution suggesting that IPS is a higher-order process involving more bilateral cortical activation. In addition, adults showed more left lateralization compared to the children during movement conditions (execution and IPS); which indicated greater inhibition of ipsilateral cortices in the adults compared to children. These findings provide a neuroimaging framework to study imitation and IPS impairments in special populations such as children with Autism Spectrum Disorder.

Effects of Equine Therapy on Individuals with Autism Spectrum Disorder: A Systematic Review.

Literature on effects of equine therapy in individuals with autism spectrum disorder (ASD) has grown in recent times. Equine therapy is an alternative multimodal intervention that involves utilizing a horse to enhance core impairments in ASD. Recent systematic reviews in this area have several limitations including inclusion of populations other than ASD, assessment of a variety of animal-assisted interventions other than equine therapy, and a failure to conduct quantitative analyses to provide accurate effect size estimates. We conducted a focused systematic review to address these limitations. Our review suggested that equine therapy has beneficial effects on behavioral skills and to some extent on social communication in ASD. The evidence for positive effects of equine therapy on perceptuo-motor, cognitive, and functional skills is currently limited.

Differences in praxis performance and receptive language during fingerspelling between deaf children with and without autism spectrum disorder.

Children with autism spectrum disorder present with a variety of social communication deficits such as atypicalities in social gaze and verbal and non-verbal communication delays as well as perceptuo-motor deficits like motor incoordination and dyspraxia. In this study, we had the unique opportunity to study praxis performance in deaf children with and without autism spectrum disorder in a fingerspelling context using American Sign Language. A total of 11 deaf children with autism spectrum disorder and 11 typically developing deaf children aged between 5 and 14 years completed a fingerspelling task. Children were asked to fingerspell 15 different words shown on an iPad. We coded various praxis errors and fingerspelling time. The deaf children with autism spectrum disorder had greater errors in pace, sequence precision, accuracy, and body part use and also took longer to fingerspell each word. Additionally, the deaf children with autism spectrum disorder had poor receptive language skills and this strongly correlated with their praxis performance and autism severity. These findings extend the evidence for dyspraxia in hearing children with autism spectrum disorder to deaf children with autism spectrum disorder. Poor sign language production in children with autism spectrum disorder may contribute to their poor gestural learning/comprehension and vice versa. Our findings have therapeutic implications for children with autism spectrum disorder when teaching sign language.

Cortical Activation during Action Observation, Action Execution, and Interpersonal Synchrony in Adults: A functional Near-Infrared Spectroscopy (fNIRS) Study.

Introduction: Humans engage in Interpersonal Synchrony (IPS) as they synchronize their own actions with that of a social partner over time. When humans engage in imitation/IPS behaviors, multiple regions in the frontal, temporal, and parietal cortices are activated including the putative Mirror Neuron Systems (Iacoboni, 2005; Buxbaum et al., 2014). In the present study, we compared fNIRS-based cortical activation patterns across three conditions of action observation ("Watch" partner), action execution ("Do" on your own), and IPS (move "Together"). Methods: Fifteen typically developing adults completed a reach and cleanup task with the right arm while cortical activation was examined using a 24-channel, Hitachi fNIRS system. Each adult completed 8 trials across three conditions (Watch, Do, and Together). For each fNIRS channel, we obtained oxy hemoglobin (HbO2) and deoxy hemoglobin (HHb) profiles. Spatial registration methods were applied to localize the cortical regions underneath each channel and to define six regions of interest (ROIs), right and left supero-anterior (SA or pre/post-central gyri), infero-posterior (IP or angular/supramarginal gyri), and infero-anterior (IA or superior/middle temporal gyri) regions. Results: In terms of task-related differences, the majority of the ROIs were more active during Do and Together compared to Watch. Only the right/ipsilateral fronto-parietal and inferior parietal cortices had greater activation during Together compared to Do. Conclusions: The similarities in cortical activation between action execution and IPS suggest that neural control of IPS is more similar to its execution than observational aspects. To be clear, the more complex the actions performed, the more difficult the IPS behaviors. Secondly, IPS behaviors required slightly more right-sided activation (vs. execution/observation) suggesting that IPS is a higher-order process involving more bilateral activation compared to its sub-components. These findings provide a neuroimaging framework to study imitation and IPS impairments in special populations such as infants at risk for and children with ASD.

Differences in object sharing between infants at risk for autism and typically developing infants from 9 to 15 months of age.

Object sharing abilities of infants at risk for autism (AR infants) and typically developing (TD) infants were compared from 9 to 15 months of age. Specifically, we examined the effects of infants' locomotor abilities on their object sharing skills. 16 TD infants and 16 AR infants were observed during an "object sharing" paradigm at crawling and walking ages. Overall, AR walking infants demonstrated lower rates of object sharing with caregivers compared to TD walking infants. Specifically, AR walking infants had lower rates of giving and approaches toward caregivers compared to TD walking infants. AR walking infants also had lower step rates toward task-appropriate targets, i.e. caregivers and objects compared to TD walking infants. No group differences in object sharing were observed at crawling ages. Object sharing could be a valuable context for early identification of delays in infants at risk for developing Autism spectrum disorder.

The effects of embodied rhythm and robotic interventions on the spontaneous and responsive social attention patterns of children with Autism Spectrum Disorder (ASD): A pilot randomized controlled trial.

We compared the effects of 8-weeks of rhythm and robotic interventions with those of a comparison, standard-of-care intervention, on the spontaneous and responsive social attention patterns of school-age children with Autism Spectrum Disorder. Attention patterns were examined within a standardized pretest/posttest measure of joint attention (JA) and a training-specific social attention measure during early, mid, and late training sessions. The rhythm and comparison groups demonstrated improvements in JA. Social attention was greater in the rhythm followed by the robot and lastly the comparison group. The robot and comparison groups spent maximum time fixating on the robot and objects, respectively. Across sessions, the robot group decreased attention to the robot and increased attention to elsewhere. Overall, rhythmic movement contexts afford sustained social monitoring in children with autism.

The effects of embodied rhythm and robotic interventions on the spontaneous and responsive verbal communication skills of children with Autism Spectrum Disorder (ASD): A further outcome of a pilot randomized controlled trial.

The current manuscript is the second in a mini-series of manuscripts reporting the effects of alternative, movement-based, rhythm and robotic interventions on the social communication skills of 36 school-age children with ASD. This pilot randomized controlled trial compared the effects of 8-weeks of rhythm and robotic interventions to those of a standard-of-care, comparison intervention. The first manuscript reported intervention effects on the spontaneous and responsive social attention skills of children. In this manuscript, we report intervention effects on the spontaneous and responsive verbal communication skills of children. Communication skills were assessed within a standardized test of responsive communication during the pretest and posttest as well as using training-specific measures of social verbalization during early, mid, and late training sessions. The rhythm and comparison groups improved on the standardized test in the posttest compared to the pretest. The rhythm and robot groups increased levels of social verbalization across training sessions. Movement-based and stationary contexts afforded different types and amounts of communication in children with ASD. Overall, movement-based interventions are a promising tool to enhance verbal and non-verbal communication skills in children with ASD.

The relative kicking frequency of infants born full-term and preterm during learning and short-term and long-term memory periods of the mobile paradigm.

BACKGROUND AND PURPOSE: Infants born preterm differ in their spontaneous kicking, as well as their learning and memory abilities in the mobile paradigm, compared with infants born full-term. In the mobile paradigm, a supine infant's ankle is tethered to a mobile so that leg kicks cause a proportional amount of mobile movement. The purpose of this study was to investigate the relative kicking frequency of the tethered (right) and nontethered (left) legs in these 2 groups of infants. SUBJECTS: Ten infants born full-term and 10 infants born preterm (<33 weeks gestational age, <2,500 g) and 10 comparison infants participated in the study. METHODS: The relative kicking frequencies of the tethered and nontethered legs were analyzed during learning and short-term and long-term memory periods of the mobile paradigm. RESULTS: Infants born full-term showed an increase in the relative kicking frequency of the tethered leg during the learning period and the short-term memory period but not for the long-term memory period. Infants born preterm did not show a change in kicking pattern for learning or memory periods, and consistently kicked both legs in relatively equal amounts. DISCUSSION AND CONCLUSION: Infants born full-term adapted their baseline kicking frequencies in a task-specific manner to move the mobile and then retained this adaptation for the short-term memory period. In contrast, infants born preterm showed no adaptation, suggesting a lack of purposeful leg control. This lack of control may reflect a general decrease in the ability of infants born preterm to use their limb movements to interact with their environment. As such, the mobile paradigm may be clinically useful in the early assessment and intervention of infants born preterm and at risk for future impairment.

Atypical object exploration in infants at-risk for autism during the first year of lifer.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder usually diagnosed by the end of the second year of life. Early signs of ASD within the first year of life are still unclear. The main purpose of the present study was to compare object exploration skills between infants at-risk for ASD and typically developing (TD) infants to determine early markers for autism within the first year of life. Sixteen at-risk infants and 16 TD infants were longitudinally followed from 6 to 15 months of age during an object exploration task involving three objects with distinct size, shape, and texture, i.e., a long rattle, a rigid circular ball, and a soft circular koosh ball. All sessions were videotaped for coding of manual exploration (grasping and dropping), oral exploration (mouthing), and visual exploration (looking). We also obtained follow-up outcomes using various developmental questionnaires at 18 months and email follow-up on developmental delays/ASD diagnosis after the infants' second birthdays. Our results showed object-based differences in exploration patterns that extended across both groups. We also noticed context-dependent group differences for various exploratory behaviors across objects and ages. Specifically, at 6 months, at-risk infants showed less grasping of the rigid ball as well as less mouthing and greater looking at the rattle compared to TD infants. At 9 and 12 months, at-risk infants demonstrated significantly lower levels of purposeful dropping of all objects and greater looking at the rattle. Lastly, at 15 months, at-risk infants showed persistent mouthing of the rigid ball and rattle compared to TD infants. In addition, 10 out of 16 at-risk infants developed various motor, social, and language delays or ASD diagnosis at follow-up. Taken together, early context-dependent delays/abnormalities in object exploration could be markers for future developmental delays in infants at-risk for autism. Moreover, promoting early object experiences through socially embedded, free and structured play could have significant implications for multisystem development including perceptuo-motor, social communication, and cognitive development in at-risk infants.

A comparison of the effects of rhythm and robotic interventions on repetitive behaviors and affective states of children with Autism Spectrum Disorder (ASD).

Repetitive behaviors and poor affect regulation are commonly seen in children with Autism Spectrum Disorder (ASD). We compared the effects of two novel interventions - rhythm and robotic therapies, with those of a standard-of-care intervention, on the repetitive behaviors and affective states of 36 children with ASD between 5 and 12 years using a randomized controlled trial design. We coded for frequencies of sensory, negative, and stereotyped behaviors and the duration of positive, negative, and interested affective states in children during early, mid, and late training sessions. In terms of repetitive behaviors, in the early session, the rhythm and robot groups engaged in greater negative behaviors, whereas the comparison group engaged in greater sensory behaviors. With training, the rhythm group reduced negative behaviors whereas there were no training-related changes in the other groups. In terms of affective states, the rhythm and robot groups showed greater negative affect, whereas the comparison group demonstrated greater interested affect across all sessions. With training, the rhythm group showed a reduction in negative affect and an increase in interested affect whereas the robot group showed a reduction in positive affect. Overall, it appears that rhythm-based interventions are socially engaging treatment tools to target core impairments in autism.

The Effects of Rhythm and Robotic Interventions on the Imitation/Praxis, Interpersonal Synchrony, and Motor Performance of Children with Autism Spectrum Disorder (ASD): A Pilot Randomized Controlled Trial.

We assessed the effects of three interventions, rhythm, robotic, and standard-of-care, on the imitation/praxis, interpersonal synchrony, and overall motor performance of 36 children with Autism Spectrum Disorder (ASD) between 5 and 12 years of age. Children were matched on age, level of functioning, and services received, prior to random assignment to one of the three groups. Training was provided for 8 weeks with 4 sessions provided each week. We assessed generalized changes in motor skills from the pretest to the posttest using a standardized test of motor performance, the Bruininks-Oseretsky Test of Motor Proficiency, 2nd edition (BOT-2). We also assessed training-specific changes in imitation/praxis and interpersonal synchrony during an early and a late session. Consistent with the training activities practiced, the rhythm and robot groups improved on the body coordination composite of the BOT-2, whereas the comparison group improved on the fine manual control composite of the BOT-2. All three groups demonstrated improvements in imitation/praxis. The rhythm and robot groups also showed improved interpersonal synchrony performance from the early to the late session. Overall, socially embedded movement-based contexts are valuable in promoting imitation/praxis, interpersonal synchrony, and motor performance and should be included within the standard-of-care treatment for children with ASD.

The performance of infants born preterm and full-term in the mobile paradigm: learning and memory.

BACKGROUND AND PURPOSE: By 3 to 4 months of age, infants born full-term and without known disease display associative learning and memory abilities in the mobile paradigm, where an infant's leg is tethered to a mobile such that leg kicks result in proportional mobile movement. The first purpose of this study was to examine the learning and memory abilities of a group of infants born full-term compared with those of a comparison group. Little is known about the learning and memory abilities in infants born preterm, a group at known risk for future impairments in learning and movement. The second purpose of this study was to determine if and when an age-adjusted group of infants born prematurely display associative learning and memory abilities over a 6-week period. SUBJECTS: Ten infants born full-term (38-42 weeks gestational age [GA]) and 10 infants born preterm (<33 weeks GA and <2,500 g) who were tethered and had control over the mobile movement were independently compared with a comparison group of 10 infants born full-term who were tethered and viewed a moving mobile but did not have control over the mobile movement. Infants in all 3 groups were seen at 3 to 4 months of age and were excluded from participation for any known visual or orthopedic diagnoses. METHODS: Infants were tested using the mobile conjugate reinforcement paradigm, where one leg is tethered to an overhead mobile such that kicking with that leg results in proportional mobile movement. The kicking rates of the full-term group and the preterm group were compared with their own initial (baseline) kicking rates and with those of the comparison group. RESULTS: After exposure to the conjugate relationship between kicking and mobile movement, the full-term group kicked more frequently compared with their own baseline levels and compared with the comparison group, fulfilling both criteria for learning and memory. In contrast, the preterm group did not increase their kicking rate according to both criteria. DISCUSSION AND CONCLUSION: These results suggest that infants born prematurely differ in their performance in the mobile paradigm as compared with age-matched infants born full-term. The mobile paradigm may provide clinicians with an important early assessment of infants' associative learning and memory abilities. Follow-up studies are needed, however, to further validate this paradigm as a clinical assessment tool.