Initial action output and feedback-guided motor behaviors in autism spectrum disorder

Abstract Background Sensorimotor issues are common in autism spectrum disorder (ASD), related to core symptoms, and predictive of worse functional outcomes. Deficits in rapid behaviors supported primarily by feedforward mechanisms, and continuous, feedback-guided motor behaviors each have been reported, but the degrees to which they are distinct or co-segregate within individuals and across development are not well understood. Methods We characterized behaviors that varied in their involvement of feedforward control relative to feedback control across skeletomotor (precision grip force) and oculomotor (saccades) control systems in 109 individuals with ASD and 101 age-matched typically developing controls (range: 5–29 years) including 58 individuals with ASD and 57 controls who completed both grip and saccade tests. Grip force was examined across multiple force (15, 45, and 85% MVC) and visual gain levels (low, medium, high). Maximum grip force also was examined. During grip force tests, reaction time, initial force output accuracy, variability, and entropy were examined. For the saccade test, latency, accuracy, and trial-wise variability of latency and accuracy were examined. Results Relative to controls, individuals with ASD showed similar accuracy of initial grip force but reduced accuracy of saccadic eye movements specific to older ages of our sample. Force variability was greater in ASD relative to controls, but saccade gain variability (across trials) was not different between groups. Force entropy was reduced in ASD, especially at older ages. We also find reduced grip strength in ASD that was more severe in dominant compared to non-dominant hands. Limitations Our age-related findings rely on cross-sectional data. Longitudinal studies of sensorimotor behaviors and their associations with ASD symptoms are needed. Conclusions We identify reduced accuracy of initial motor output in ASD that was specific to the oculomotor system implicating deficient feedforward control that may be mitigated during slower occurring behaviors executed in the periphery. Individuals with ASD showed increased continuous force variability but similar levels of trial-to-trial saccade accuracy variability suggesting that feedback-guided refinement of motor commands is deficient specifically when adjustments occur rapidly during continuous behavior. We also document reduced lateralization of grip strength in ASD implicating atypical hemispheric specialization.

Download Full-text

Visual and proprioceptive feedback mechanisms of precision manual motor control in autism spectrum disorder

10.21203/rs.3.rs-387580/v1 ◽

2021 ◽

Author(s):

Robin L Shafer ◽

Zheng Wang ◽

James Bartolotti ◽

Matthew W. Mosconi

Keyword(s):

Autism Spectrum Disorder ◽

Visual Feedback ◽

Grip Force ◽

Motor Behavior ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Proprioceptive Feedback ◽

Force Variability ◽

Tendon Vibration ◽

Motor Behaviors

Abstract Background Individuals with Autism Spectrum Disorder (ASD) show deficits processing sensory feedback to reactively adjust ongoing motor behaviors. Atypical reliance on visual and proprioceptive feedback each have been reported during motor behaviors in ASD suggesting that impairments are not specific to one sensory domain but may instead reflect a deficit in multisensory processing, resulting in reliance on unimodal feedback. The present study tested this hypothesis by examining motor behavior across different visual and proprioceptive feedback conditions during a visually guided precision grip force test. Methods Participants with ASD (N = 43) and age-matched typically developing (TD) controls (N = 23), range 10–20 years, completed a test of precision gripping. They pressed on force sensors with their index finger and thumb while receiving visual feedback on a computer screen in the form of a horizontal bar that moved upwards with increased force. They were instructed to press so that the bar reached the level of a static target bar and then to hold their grip force as steadily as possible. Visual feedback was manipulated by changing the gain of the force bar. Proprioceptive feedback was manipulated by applying 80 Hz tendon vibration at the wrist to induce an illusion of muscle elongation. Force variability (standard deviation) and irregularity (sample entropy) were examined using multilevel linear models. Results While TD controls showed increased force variability with the tendon vibration on compared to off, individuals with ASD showed similar levels of force variability across tendon vibration conditions. Individuals with ASD showed stronger age-associated reductions in force variability relative to controls across conditions. The ASD group also showed greater age-associated increases in force irregularity relative to controls, especially at higher gain levels and when the tendon vibrator was turned on. Conclusions Our findings that individuals with ASD show similar levels of force variability and regularity during induced proprioceptive illusions suggest a reduced ability to integrate proprioceptive feedback information to guide ongoing precision manual motor behavior. We also document stronger age-associated gains in force control in ASD relative to TD suggesting delayed development of multisensory feedback control of motor behavior.

Download Full-text

Distinct Sensorimotor Feedforward and Feedback Deficits Vary with Age in Individuals with Autism Spectrum disorder

10.21203/rs.3.rs-152611/v1 ◽

2021 ◽

Author(s):

Kathryn E Unruh ◽

Walker S McKinney ◽

Kandace K Fleming ◽

John A Sweeney ◽

Matthew W Mosconi

Keyword(s):

Autism Spectrum Disorder ◽

Eye Movements ◽

Motor Behavior ◽

Precision Grip ◽

Saccadic Eye Movements ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Force Variability ◽

Motor Behaviors ◽

Age Related

Abstract Background: Sensorimotor issues are common in autism spectrum disorder (ASD), related to core symptoms, and predictive of worse functional outcomes. Deficits in rapid, feedforward processes executed prior to availability of sensory feedback, and continuous, feedback-guided motor behaviors each have been reported, but the degree to which these deficits are distinct or co-segregate in individuals is not well understood. Methods: To characterize feedforward and feedback control of motor behavior in ASD, we examined saccadic eye movements (feedforward) and sustained precision gripping (feedback) in 109 individuals with ASD and 101 age-matched typically developing (TD) controls (range: 5-28 years). We measured latency and gain of saccades and error, variability, and regularity of precision grip. Linear mixed effects models were conducted to examine whether sensorimotor behavior varied according to diagnostic group, age, handedness, and sex. Results: Individuals with ASD showed reduced accuracy of saccadic eye movements relative to controls, and their dysmetria was more severe at older ages. Individuals with ASD showed increased precision grip force variability relative to controls, especially at younger ages, while increased motor regularity was more pronounced in older individuals with ASD. Feedforward and feedback motor behaviors were strongly inter-related among controls, but not among individuals with ASD. Saccade dysmetria and increased force variability were associated with ASD symptom severity. Limitations: Our age-related findings rely on cross-sectional data. Longitudinal studies of component motor skills and their associations with clinical outcomes are needed to clarify neurodevelopmental mechanisms of core and associated symptoms of ASD. Feedforward behavior was characterized in the oculomotor system using ballistic movements completed too rapidly to be guided by online feedback; however, future studies are needed to examine feedforward and feedback processes across both manual and oculomotor systems. Conclusions: These findings suggest that separate neurodevelopmental mechanisms contribute to feedforward and feedback motor deficits in ASD, and that they are more manifest at different stages in life span development. Our results highlight the needs for more fine-grained approaches to parse separate motor impairments that often are considered as a unitary deficit in ASD, and to characterize variation in motor behaviors across development.

Download Full-text

Visual and somatosensory feedback mechanisms of precision manual motor control in autism spectrum disorder

Journal of Neurodevelopmental Disorders ◽

10.1186/s11689-021-09381-2 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Robin L. Shafer ◽

Zheng Wang ◽

James Bartolotti ◽

Matthew W. Mosconi

Keyword(s):

Autism Spectrum Disorder ◽

Visual Feedback ◽

Grip Force ◽

Motor Behavior ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Force Variability ◽

Tendon Vibration ◽

Motor Behaviors ◽

Somatosensory Feedback

Abstract Background Individuals with autism spectrum disorder (ASD) show deficits processing sensory feedback to reactively adjust ongoing motor behaviors. Atypical reliance on visual and somatosensory feedback each have been reported during motor behaviors in ASD suggesting that impairments are not specific to one sensory domain but may instead reflect a deficit in multisensory processing, resulting in reliance on unimodal feedback. The present study tested this hypothesis by examining motor behavior across different visual and somatosensory feedback conditions during a visually guided precision grip force test. Methods Participants with ASD (N = 43) and age-matched typically developing (TD) controls (N = 23), ages 10–20 years, completed a test of precision gripping. They pressed on force transducers with their index finger and thumb while receiving visual feedback on a computer screen in the form of a horizontal bar that moved upwards with increased force. They were instructed to press so that the bar reached the level of a static target bar and then to hold their grip force as steadily as possible. Visual feedback was manipulated by changing the gain of the force bar. Somatosensory feedback was manipulated by applying 80 Hz tendon vibration at the wrist to disrupt the somatosensory percept. Force variability (standard deviation) and irregularity (sample entropy) were examined using multilevel linear models. Results While TD controls showed increased force variability with the tendon vibration on compared to off, individuals with ASD showed similar levels of force variability across tendon vibration conditions. Individuals with ASD showed stronger age-associated reductions in force variability relative to controls across conditions. The ASD group also showed greater age-associated increases in force irregularity relative to controls, especially at higher gain levels and when the tendon vibrator was turned on. Conclusions Our findings that disrupting somatosensory feedback did not contribute to changes in force variability or regularity among individuals with ASD suggests a reduced ability to integrate somatosensory feedback information to guide ongoing precision manual motor behavior. We also document stronger age-associated gains in force control in ASD relative to TD suggesting delayed development of multisensory feedback control of motor behavior.

Download Full-text

Early differences in auditory processing relate to Autism Spectrum Disorder traits in infants with Neurofibromatosis Type I

Journal of Neurodevelopmental Disorders ◽

10.1186/s11689-021-09364-3 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Jannath Begum-Ali ◽

◽

Anna Kolesnik-Taylor ◽

Isabel Quiroz ◽

Luke Mason ◽

...

Keyword(s):

Autism Spectrum Disorder ◽

Auditory Processing ◽

Neurofibromatosis Type ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Type I ◽

Sensory Reactivity ◽

Auditory Responses ◽

Repetition Suppression ◽

Age Related

Abstract Background Sensory modulation difficulties are common in children with conditions such as Autism Spectrum Disorder (ASD) and could contribute to other social and non-social symptoms. Positing a causal role for sensory processing differences requires observing atypical sensory reactivity prior to the emergence of other symptoms, which can be achieved through prospective studies. Methods In this longitudinal study, we examined auditory repetition suppression and change detection at 5 and 10 months in infants with and without Neurofibromatosis Type 1 (NF1), a condition associated with higher likelihood of developing ASD. Results In typically developing infants, suppression to vowel repetition and enhanced responses to vowel/pitch change decreased with age over posterior regions, becoming more frontally specific; age-related change was diminished in the NF1 group. Whilst both groups detected changes in vowel and pitch, the NF1 group were largely slower to show a differentiated neural response. Auditory responses did not relate to later language, but were related to later ASD traits. Conclusions These findings represent the first demonstration of atypical brain responses to sounds in infants with NF1 and suggest they may relate to the likelihood of later ASD.

Download Full-text

Functional Networks Abnormalities in Autism Spectrum Disorder: Age-Related Hypo and Hyper Connectivity

Brain Topography ◽

10.1007/s10548-021-00831-7 ◽

2021 ◽

Author(s):

Hossein Haghighat ◽

Mitra Mirzarezaee ◽

Babak Nadjar Araabi ◽

Ali Khadem

Keyword(s):

Autism Spectrum Disorder ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Functional Networks ◽

Age Related

Download Full-text

Intact context memory performance in adults with autism spectrum disorder

Scientific Reports ◽

10.1038/s41598-021-99898-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sidni A. Justus ◽

Patrick S. Powell ◽

Audrey Duarte

Keyword(s):

Autism Spectrum Disorder ◽

Selective Attention ◽

Episodic Memory ◽

Memory Performance ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Memory Accuracy ◽

Age Related ◽

Adults With Asd ◽

Context Memory

AbstractResearch on memory in autism spectrum disorder (ASD) finds increased difficulty encoding contextual associations in episodic memory and suggests executive dysfunction (e.g., selective attention, cognitive flexibility) and deficient metacognitive monitoring as potential contributing factors. Findings from our lab suggest that age-related impairments in selective attention contribute to those in context memory accuracy and older adults tended to show dependence in context memory accuracy between relevant and irrelevant context details (i.e., hyper-binding). Using an aging framework, we tested the effects of selective attention on context memory in a sample of 23 adults with ASD and 23 typically developed adults. Participants studied grayscale objects flanked by two types of contexts (color, scene) on opposing sides and were told to attend to only one object-context relationship, ignoring the other context. At test, participants made object and context recognition decisions and judgment of confidence decisions allowing for an evaluation of context memory performance, hyper-binding, and metacognitive performance for context judgments in a single task. Results showed that adults with ASD performed similarly to typically developed adults on all measures. These findings suggest that context memory performance is not always disrupted in adults with ASD, even when demands on selective attention are high. We discuss the need for continued research to evaluate episodic memory in a wider variety of adults with ASD.

Download Full-text

Electrophysiological signatures of brain aging in autism spectrum disorder

10.1101/2021.03.18.434885 ◽

2021 ◽

Author(s):

Abigail Dickinson ◽

Shafali Jeste ◽

Elizabeth Milne

Keyword(s):

Autism Spectrum Disorder ◽

Brain Aging ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Aging Brain ◽

Significant Group ◽

Care Plans ◽

Alpha Frequency ◽

Age Related ◽

Adults With Asd

AbstractEmerging evidence suggests that aging processes may be altered in adults with autism spectrum disorder (ASD). However, it remains unclear if oscillatory slowing, a key neurophysiological change in the aging brain, manifests atypically in this population. This study sought to examine patterns of age-related oscillatory slowing in adults with ASD, captured by reductions in the brain’s peak alpha frequency. Resting-state EEG data from adults (18-70 years) with ASD (N=93) and age-matched neurotypical (NT) controls (N=87) were pooled from three independent datasets. A robust curve-fitting procedure quantified the peak frequency of alpha oscillations (7-13Hz) across all brain regions. Associations between peak alpha frequency and age were assessed and compared between groups. Consistent with characteristic patterns of oscillatory slowing, peak alpha frequency was negatively associated with age across the entire sample (p<.0001). A significant group by age interaction revealed that this relationship was more pronounced in adults with ASD (p<.01), suggesting that that age-related oscillatory slowing may be accelerated in this population. Scalable EEG measures such as peak alpha frequency could provide insights into neural aging that are crucially needed to inform care plans and preventive interventions that can promote successful aging in ASD.

Download Full-text