Resting Frontal Gamma Power is Associated with Both Expressive Language and Non-verbal Cognitive Abilities in Young Autistic Children.

Previous research links resting frontal gamma power to key developmental outcomes in young neurotypical (NT) children and infants at risk for language impairment. However, it remains unclear whether gamma power is specifically associated with language or with more general cognitive abilities among young children diagnosed with autism spectrum disorder (ASD). The current study evaluates differences in resting frontal gamma power between young autistic and NT children and tests whether gamma power is uniquely associated with individual differences in expressive language, receptive language and non-verbal cognitive abilities in autistic and NT children. Participants included 48 autistic children and 58 age- and sex-matched NT children (ages 22-60 months). Baseline electroencephalography (EEG) recordings were acquired from each participant. Children also completed the Mullen Scales of Early Learning (MSEL). We found that frontal gamma power at rest did not differ between autistic and NT children. Among autistic children, reduced frontal gamma power was significantly associated with both higher expressive language skills and higher non-verbal cognitive skills, controlling for age and sex. The interaction between frontal gamma power and diagnostic status no longer explained unique variance in expressive language skills after controlling for variance associated with non-verbal cognitive skills across autistic and NT children. Together, these findings suggest that reduced gamma power is associated with both better expressive language and non-verbal cognitive skills among young autistic children. Moreover, associations between high frequency neural activity and cognition are not specific to verbal abilities but reflect neural mechanisms associated with general higher-order cognitive abilities in ASD.

Sensorimotor representation of observed dyadic actions with varying agent involvement: an EEG mu study.

Observation of others' actions activates motor representations in sensorimotor cortex. Although action observation in the real-world often involves multiple agents displaying varying degrees of action involvement, most lab studies on action observation studied individual actions. We recorded EEG-mu suppression over sensorimotor cortex to investigate how the multi-agent nature of observed hand/arm actions is incorporated in sensorimotor action representations. Hereto we manipulated the extent of agent involvement in dyadic interactions presented in videos. In all clips two agents were present, of which agent-1 always performed the same action, while the involvement of agent-2 differed along three levels: (1) passive and uninvolved, (2) passively involved, (3) actively involved. Additionally, a no-action condition was presented. The occurrence of these four conditions was predictable thanks to cues at the start of each trial, which allowed to study possible mu anticipation effects. Dyadic interactions in which agent-2 was actively involved resulted in increased power suppression of the mu rhythm compared to dyadic interactions in which agent-2 was passively involved. The latter did not differ from actions in which agent-2 was present but not involved. No anticipation effects were found. The results suggest that the sensorimotor representation of a dyadic interaction takes into account the simultaneously performed bodily articulations of both agents, but no evidence was found for incorporation of their static articulated postures.

Sensorimotor anticipation of others' actions in real-world and video settings: Modulation by level of engagement?

Electroencephalography (EEG) studies investigating social cognition have used both video and real-world stimuli, often without a strong reasoning as to why one or the other was chosen. Video stimuli can be selected for practical reasons, while naturalistic real-world stimuli are ecologically valid. The current study investigated modulatory effects on EEG mu (8-13 Hz) suppression, directly prior to the onset - and during the course - of observed actions, related to real-world and video settings. Recordings were made over sensorimotor cortex and stimuli in both settings consisted of identical (un)predictable object-related grasping and placing actions. In both settings, a very similar mu suppression was found during unfolding of the action, irrespective of predictability. However, mu suppression related to the anticipation of upcoming predictable actions was found exclusively in the real-world setting. Thus, even though the presentation setting does not seem to modulate mu suppression during action observation, it does affect the anticipation-related mu suppression. We discuss the possibility that this may be due to increased social engagement in real-world settings, which in particular affects anticipation. The findings emphasize the importance of using real-world stimuli to bring out the subtle, anticipatory, aspects related to action observation.

Eliciting Language Samples for Analysis (ELSA): A New Protocol for Assessing Expressive Language and Communication in Autism.

Expressive language and communication are among the key targets of interventions for individuals with autism spectrum disorder (ASD), and natural language samples provide an optimal approach for their assessment. Currently, there are no protocols for collecting such samples that cover a wide range of ages or language abilities, particularly for children/adolescents who have very limited spoken language. We introduce a new protocol for collecting language samples, eliciting language samples for analysis (ELSA), and a novel approach for deriving basic measures of verbal communicative competence from it that bypasses the need for time-consuming transcription. Study 1 presents ELSA-adolescents (ELSA-A), designed for minimally and low-verbal older children/adolescents with ASD. The protocol successfully engaged and elicited speech from 46 participants across a wide range of ages (6;6-19;7) with samples averaging 20-25 min. The collected samples were segmented into speaker utterances (examiner and participant) using real-time coding as one is listening to the audio recording and two measures were derived: frequency of utterances and conversational turns per minute. These measures were shown to be reliable and valid. For Study 2, ELSA was adapted for younger children (ELSA-Toddler [ELSA-T]) with samples averaging 29 min from 19 toddlers (2;8-4;10 years) with ASD. Again, measures of frequency of utterances and conversational turns derived from ELSA-T were shown to have strong psychometric properties. In Study 3, we found that ELSA-A and ELSA-T were equivalent in eliciting language from 17 children with ASD (ages: 4;0-6;8), demonstrating their suitability for deriving robust objective assessments of expressive language that could be used to track change in ability over time. We introduce a new protocol for collecting expressive language samples, ELSA, that can be used with a wide age range, from toddlers (ELSA-T) to older adolescents (ELSA-A) with ASD who have minimal or low-verbal abilities. The measures of language and communication derived from them, frequency of utterances, and conversational turns per minute, using real-time coding methods, can be used to characterize ability and chart change in intervention research. LAY SUMMARY: We introduce a new protocol for collecting expressive language samples, ELSA, that can be used with a wide age range, from toddlers (ELSA-T) to older adolescents (ELSA-A) with autism spectrum disorder who have minimal or low-verbal abilities. The measures of language and communication derived from them, frequency of utterances and conversational turns per minute, using real-time coding methods, can be used to characterize ability and chart change in intervention research.

Brain correlates of motor complexity during observed and executed actions.

Recently, cortical areas with motor properties have attracted attention widely to their involvement in both action generation and perception. Inferior frontal gyrus (IFG), ventral premotor cortex (PMv) and inferior parietal lobule (IPL), presumably consisting of motor-related areas, are of particular interest, given that they respond to motor behaviors both when they are performed and observed. Converging neuroimaging evidence has shown the functional roles of IFG, PMv and IPL in action understanding. Most studies have focused on the effects of modulations in goals and kinematics of observed actions on the brain response, but little research has explored the effects of manipulations in motor complexity. To address this, we used fNIRS to examine the brain activity in the frontal, motor, parietal and occipital regions, aiming to better understand the brain correlates involved in encoding motor complexity. Twenty-one healthy adults executed and observed two hand actions that differed in motor complexity. We found that motor complexity sensitive brain regions were present in the pars opercularis IFG/PMv, primary motor cortex (M1), IPL/supramarginal gyrus and middle occipital gyrus (MOG) during action execution, and in pars opercularis IFG/PMv and M1 during action observation. Our findings suggest that the processing of motor complexity involves not only M1 but also pars opercularis IFG, PMv and IPL, each of which plays a critical role in action perception and execution.

Sensorimotor cortex activation during anticipation of upcoming predictable but not unpredictable actions.

The mirror neuron system (MNS) becomes active during action execution and action observation, which is presumably reflected by reductions in mu (8-13 Hz) activity in the electroencephalogram over the sensorimotor cortex. The function of the MNS is still fiercely debated. The current study aimed to investigate a role of the MNS in anticipating others' actions by examining whether the MNS was activated - indexed by mu power suppression - prior to the onset of observed actions when the onset and type of action could be predicted on the basis of environmental cues. Young adults performed and observed cued grasping and placing actions in a card game in a real-life setting, while the predictability of the observed actions was manipulated using rules. Significant mu suppression, relative to within-trial baseline activity, was found both prior to and during executed actions, but also during action observation, and, crucially, prior to observed actions provided they were predictable. No anticipatory mu reductions were found prior to unpredictable observed actions. These results suggest top-down modulation of MNS activity by conceptual knowledge. This is the first study to demonstrate mu suppression prior to action onset - possibly reflecting MNS anticipatory activity - by explicitly manipulating predictability.