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Introduction: Motor difficulties are frequent in autistic children and associated with diverse social behavior, possibly due to atypical neural processing subserving internal action models. This systematic review synthesizes results from current functional magnetic resonance imaging (fMRI) research of brain activation during execution, imitation and observation of naturalistic actions in autistic children and adolescents (<18 years).

Methods: Peer-reviewed articles in English published between 2000 and 2025 reporting task-related fMRI in diagnosed autistic vs. typically developing youth (<18 years) were evaluated. Eight studies (with a total of 129 autistic and 128 typically developing participants) were identified, divided into action execution (n = 1), observation (n = 4), and imitation (n = 3).

Results: Between-group differences included reduced cerebellar activations for execution in autistic children; higher activity in left-lateralized motor processing regions for imitation; and lower activity in temporoparietal, posterior cingulate and anterior prefrontal cortex for observation.

Discussion: Findings suggest that atypical brain activation during action execution, observation and imitation in autistic youth is frequent and largely support the notion of aberrant formation and use of motor representations in autism development. Although, due to the limited number of studies, small samples, variability in fMRI pipelines, and task specific nature of the results, interpretations require caution and further investigations are warranted.

Sequential manual actions involving object manipulation, whether performed ourselves or observed in others, are a fundamental part of our daily lives. Motor representations within internal action models have been linked to both action execution and observation, but it is less clear how brain activity associated with planning, execution and observation of complex sequential actions differs and overlap. Here, using event-related fMRI, we examined brain activity during sequential manual action in planning, execution and observation in a sample of healthy adults (N = 28). Comparing actions under different task complexity (complex, rotation > baseline, no rotation), we found increased activation in parietal, precentral and sensory-motor regions during action execution planning. Execution of complex actions engaged ipsilateral parieto-frontal regions, while observation activated parietal regions. Planning to observe complex actions engaged occipito-parietal, precentral and cerebellar regions. Importantly, across all four conditions, we found a significant overlap in brain activity in the bilateral intraparietal sulcus. This suggests that the inferior parietal lobe is an important node for complex sequential manual actions.

Motor impairments are common in individuals with autism spectrum disorder (ASD) although less is known about the neural mechanisms related to such difficulties. This review provides an outline of functional magnetic resonance imaging (fMRI) findings associated with execution and observation of naturalistic actions in autistic adults. Summarized outcomes revealed that adults with ASD recruit similar brain regions as neurotypical adults during action execution and during action observation, although with a difference in direction and/or magnitude. For action execution, this included higher and lower activity bilaterally in the precentral cortex, the parietal cortex, the inferior frontal gyrus (IFG), the middle temporal gyrus (MTG), the occipital cortex, and the cerebellum. For action observation, differences mainly concerned both higher and lower activity in bilateral IFG and right precentral gyrus, and lower activity in MTG. Activity overlaps between action execution and observation highlight atypical recruitment of IFG, MTG, precentral, and parieto-occipital regions in ASD. The results show atypical recruitment of brain regions subserving motor planning and/or predictive control in ASD. Atypical brain activations during action observation, and the pattern of activity overlaps, indicate an association with difficulties in understanding others' actions and intentions.

Motor issues are frequently observed accompanying core deficits in autism spectrum disorder (ASD). Impaired motor behavior has also been linked to cognitive and social abnormalities, and problems with predictive ability have been suggested to play an important, possibly shared, part across all these domains. Brain imaging of sensory-motor behavior is a promising method for characterizing the neurobiological foundation for this proposed key trait. The present functional magnetic resonance imaging (fMRI) developmental study, involving children/youth with ASD, typically developing (TD) children/youth, and neurotypical adults, will investigate brain activations during execution and observation of a visually guided, goal-directed sequential (two-step) manual task. Neural processing related to both execution and observation of the task, as well as activation patterns during the preparation stage before execution/observation will be investigated. Main regions of interest include frontoparietal and occipitotemporal cortical areas, the human mirror neuron system (MNS), and the cerebellum.

Emotional stimuli are argued to capture attention and consume attentional resources differently depending on their emotionalcontent. The present study investigates the impact of the automatic detection of unexpected and to-be-ignored emotional stimuli onhuman behavioral responses, and aims to unravel the differences in distraction between two negative emotional stimuli: sadness and anger.Forty participants (Mage= 25.5 years) performed a visual categorization task where angry and sad emoji faces were presented after eithera standard neutral tone (in 80% of trials) or a deviant emotional sound (tone changing in pitch; sad or angry sound in 10% of trials each)that was to be ignored. Deviant trials were either congruent (e.g., sad sound—sad face) or incongruent (e.g., angry sound—sad face).Although the stimuli presented to the participants were brief and to-be-ignored, results indicate that participants were significantly moredistracted by sad compared to angry stimuli (seen as prolonged response times). Findings are discussed with reference to the nature ofthe two negative emotions.

The involuntary shift of attention to emotional sounds were investigated in a cross-modal oddball task in which participants categorized angry and disappointed emoji faces. Prior to each face, a standard tone was presented (80% of trials) or a deviant “disappointed” or a buzzing “angry” sound (20% of trials). The deviant trials were either congruent (e.g., disappointed sound/disappointed emoji) or incongruent trials (e.g., a disappointed sound/angry emoji). Results showed that the emotional content of the deviant sounds interacted with the processing of the faces, but that the effect was only present in the congruent trials. Participants showed deviance distraction (prolonged response times compared to standard) in the disappointed trials and facilitation (no deviance distraction) in the angry deviant trials. The facilitation (or lack of distraction) caused by the angry deviant sound in the congruent trial may have been a result of an arousal effect due to the processing of threat.

Motor issues are frequently observed accompanying core deficits in autism spectrum disorder (ASD). Impaired motor behavior has also been linked to cognitive and social abnormalities, and problems with predictive ability have been suggested to play an important, possibly shared, part across all these domains. Brain imaging of sensory-motor behavior is a promising method for characterizing the neurobiological foundation for this proposed key trait. The present functional magnetic resonance imaging (fMRI) developmental study, involving children/youth with ASD, typically developing (TD) children/youth, and neurotypical adults, will investigate brain activations during execution and observation of a visually guided, goal-directed sequential (two-step) manual task. Neural processing related to both execution and observation of the task, as well as activation patterns during the preparation stage before execution/observation will be investigated. Main regions of interest include frontoparietal and occipitotemporal cortical areas, the human mirror neuron system (MNS), and the cerebellum.