No abstract

a b s t r a c t a r t i c l e i n f oArticle history: Accepted 2 January 2015 Available online 9 January 2015 Keywords:Mu rhythms Beta rhythms Embodied meaning Action language Perceptive language EEG mu rhythms (8-13 Hz) recorded at fronto-central electrodes are generally considered as markers of motor cortical activity in humans, because they are modulated when participants perform an action, when they observe another's action or even when they imagine performing an action. In this study, we analyzed the time-frequency (TF) modulation of mu rhythms while participants read action language ("You will cut the strawberry cake"), abstract language ("You will doubt the patient's argument"), and perceptive language ("You will notice the bright day"). The results indicated that mu suppression at fronto-central sites is associated with action language rather than with abstract or perceptive language. Also, the largest difference between conditions occurred quite late in the sentence, while reading the first noun, (contrast Action vs. Abstract), or the second noun following the action verb (contrast Action vs. Perceptive). This suggests that motor activation is associated with the integration of words across the sentence beyond the lexical processing of the action verb. Source reconstruction localized mu suppression associated with action sentences in premotor cortex (BA 6). The present study suggests (1) that the understanding of action language activates motor networks in the human brain, and (2) that this activation occurs online based on semantic integration across multiple words in the sentence.

The association of autism spectrum disorder (ASD) with an altered mirror neuron system is still controversial. At the same time, the processing of object affordances by persons with ASD is a neglected issue. In this electroencephalographic study, adults differing in their autism quotient (AQ) scores were selected. We found anomalous modulation of mu and beta rhythms in high‐AQ, compared to low‐AQ persons, while they watched a set of goal‐directed manual actions. This confirms that observing actions involving implicit intentions most clearly reveals the impairment of the mirror neurons system (MNS). The high‐AQ group also showed anomalous mu and beta modulation when they looked at pictures of manipulable objects, indicating a deficit in processing motor affordances. We conclude that high‐AQ adults have neural impairment of both the MNS and the affordance systems, which could underlie their relational problems with both people and objects. Autism Res 2019, 12: 1032–1042. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. Lay Summary Adults with autistic traits (high‐autism quotient [AQ] scores) and matched controls (low‐AQ) observed intentional hand actions, and pictures of manipulable and non‐manipulable objects. The high‐AQ group compared to the control group, showed anomalous modulation of the electroencephalographic motoric rhythms (mu and beta) while observing familiar goal‐directed actions, confirming an impairment of their mirror neuron system. Also, their brain rhythms were anomalous when they watched manipulable objects, which suggest a dysfunction in their relation with objects (affordance system).

Persons with autism spectrum disorder (ASD) have impaired mentalizing skills. In this study, a group of persons with ASD traits (high-AQ scores) initially received sham tDCS before completing a pre-test in two mentalizing tasks: false belief and self-other judgments. Over the next week, on four consecutive days, they received sessions of anodal electrical stimulation (a-tDCS) over the right temporo-parietal junction (rTPJ), a region frequently associated with the theory of mind. On the last day, after the stimulation session, they completed a new set of mentalizing tasks. A control group (with low-AQ scores) matched in age, education and intelligence received just sham stimulation and completed the same pre-test and post-test. The results showed that the high-AQ group improved their performance (faster responses), after a-tDCS, in the false belief and in the self-other judgments of mental features, whereas they did not change performance in the false photographs or the self-other judgments of physical features. These selective improvements cannot be attributed to increased familiarity with the tasks, because the performance of the low-AQ control group remained stable about one week later. Therefore, our study provides initial proof that tDCS could be used to improve mentalizing skills in persons with ASD traits.

No abstract