Valentin Begel

Individuals with Parkinson's disease (PD) experience rhythm disorders in a number of motor tasks, such as (i) oral diadochokinesis, (ii) finger tapping, and (iii) gait. These common motor deficits may be signs of "general dysrhythmia", a central disorder spanning across effectors and tasks, and potentially sharing the same neural substrate. However, to date, little is known about the relationship between rhythm impairments across domains and effectors. To test this hypothesis, we assessed whether rhythmic disturbances in three different domains (i.e., orofacial, manual, and gait) can be related in PD. Moreover, we investigated whether rhythmic motor performance across these domains can be predicted by rhythm perception, a measure of central rhythmic processing not confounded with motor output. Twenty-two PD patients (mean age: 69.5 ± 5.44) participated in the study. They underwent neurological and neuropsychological assessments, and they performed three rhythmic motor tasks. For oral diadochokinesia, participants had to repeatedly produce a trisyllable pseudoword. For gait, they walked along a computerized walkway. For the manual task, patients had to repeatedly produce finger taps. The first two rhythmic motor tasks were unpaced, and the manual tapping task was performed both without a pacing stimulus and musically paced. Rhythm perception was also tested. We observed that rhythmic variability of motor performances (inter-syllable, inter-tap, and inter-stride time error) was related between the three functions. Moreover, rhythmic performance was predicted by rhythm perception abilities, as demonstrated with a logistic regression model. Hence, rhythm impairments in different motor domains are found to be related in PD and may be underpinned by a common impaired central rhythm mechanism, revealed by a deficit in rhythm perception. These results may provide a novel perspective on how interpret the effects of rhythm-based interventions in PD, within and across motor domains.

Temporal accounts of Developmental Dyslexia (DD) postulate that a timing impairment plays an important role in this learning disorder. However, DD has been associated with timing disorders as well as other motor and cognitive dysfunctions. It is still unclear whether nonverbal timing skills per se may be considered as independent determinants of DD. In this study, we investigated the independent contribution of predictive timing to DD above and beyond the motor and cognitive dysfunctions typically associated with this disorder. Twenty-one children with DD (aged 8-12, nine females) and 27 controls (14 females) were evaluated on perceptual timing, finger tapping, fine motor control, as well as attention and executive tasks. Participants were native French speakers from various socioeconomic backgrounds. The performance of children with DD was poorer than that of controls in most of the tasks. Predictors of DD, as identified by logistic regression modeling, were beat perception and precision in tapping to the beat, which are both predictive timing variables, children's tapping rate, and cognitive flexibility. These data support temporal accounts of DD in which predictive timing impairments partially explain the core phonological deficit, independent from general motor and cognitive functioning, making predictive timing a valuable tool for early diagnosis and remediation of DD.

In this multiple single-cases study, we used dance to train sensorimotor synchronization (SMS), motor, and cognitive functions in children with developmental cerebellar anomalies (DCA). DCA are rare dysfunctions of the cerebellum that affect motor and cognitive skills. The cerebellum plays an important role in temporal cognition, including SMS, which is critical for motor and cognitive development. Dancing engages the SMS neuronal circuitry, composed of the cerebellum, the basal ganglia, and the motor cortices. Thus, we hypothesized that dance has a beneficial effect on SMS skills and associated motor and cognitive functions in children with DCA. Seven children (aged 7-11) with DCA participated in a 2-month dance training protocol (3 h/week). A test-retest design protocol with multiple baselines was used to assess children's SMS skills as well as motor, cognitive, and social abilities. SMS skills were impaired in DCA before the training. The training led to improvements in SMS (reduced variability in paced tapping), balance, and executive functioning (cognitive flexibility), as well as in social skills (social cognition). The beneficial effects of the dance training were visible in all participants. Notably, gains were maintained 2 months after the intervention. These effects are likely to be sustained by enhanced activity in SMS brain networks due to the dance training protocol.

Laura Harrison Brain and Creativity Institute, University of Southern California, United States of America Using Live Face-to-Face Functional Magnetic Resonance Imaging to Investigate the Social Brain in Autism Presented at the 3 International Conference of the ESCAN, June 23-26 2016, Portugal; 22 Annual Meeting of the Organization for Human Brain Mapping, June 27-3

Rhythm perception and production can be disrupted by neurological or neurodevelopmental disorders (e.g., Parkinson's disease, dyslexia). Rhythm deficits are associated with poor performance in language, attention, and working memory tasks. Retraining rhythmic skills may thus provide a promising avenue for improving these associated cognitive functions. To this end, here we present a new protocol for selective training of rhythmic skills implemented in a tablet serious game called Rhythm Workers. Experiment 1 served to select 54 musical excerpts based on the tapping performance of 18 non-musicians who moved to the beat of music. The excerpts were sorted in terms of the difficulty of tracking their beat, and assigned to different difficulty levels in the game. In Experiment 2, the training protocol was devised and tested in a proof-of-concept study, including two versions of the game. One version (tapping version) required a synchronized motor response (via tapping), while the other (perception version) asked for a perceptual judgment. Ten participants were trained with one version and 10 with the other version of Rhythm Workers, for 2 weeks. A control group (n ¼ 10) did not receive any training. Participants in the experimental groups showed high compliance and motivation in playing the game. The effect of the training on rhythm skills yielded encouraging results with both versions of the game. Rhythm Workers thus appears to be a motivating and potentially efficient way to train rhythmic abilities in healthy young adults, with possible applications for (re)training these skills in individuals with rhythm disorders.

Children and adults with Attention-Deficit Hyperactivity Disorder (ADHD) fail in simple tasks like telling whether two sounds have different durations, or in reproducing single durations. The deficit is linked to poor reading, attention, and language skills. Here we demonstrate that these timing distortions emerge also when tracking the beat of rhythmic sounds in perceptual and sensorimotor tasks. This contrasts with the common observation that durations are better perceived and produced when embedded in rhythmic stimuli. Children and adults with ADHD struggled when moving to the beat of rhythmic sounds, and when detecting deviations from the beat. Our findings point to failure in generating an internal beat in ADHD while listening to rhythmic sounds, a function typically associated with the basal ganglia. Rhythm-based interventions aimed at reinstating or compensating this malfunctioning circuitry may be particularly valuable in ADHD, as already shown for other neurodevelopmental disorders, such as dyslexia and Specific Language Impairment. More than 5% of children show poor concentration, impulsivity and visible signs of hyperactivity 1 , either alone or in combination. This condition, named Attention Deficit/Hyperactivity Disorder (ADHD), is the most common neurobehavioral disorder of childhood 2. Akin to other neurodevelopmental disorders such as dyslexia and Developmental Coordination Disorder 1 , it comes with poor school success and socioeconomic disadvantages 3. While many children outgrow it, in about 50% of the cases ADHD carries over into adulthood with negative consequences at work and in everyday life 4. Children and adults with ADHD also struggle in perceiving and reproducing event durations. They have difficulties in telling or reproducing the duration of visual and auditory stimuli and in comparing time intervals 5. Distortions in duration perception and production are also reported in other neurodevelopmental disorders such as autism spectrum disorders and dyslexia 6, 7. Impaired timing is associated with poor reading, attention and language skills, and with impaired executive functions 5, 8. The neural substrates of processing event durations (i.e., duration-based timing) include cerebellar-cortical pathways 9. Structural anomalies in these brain regions (e.g., inferior or posterior vermis) and impaired connectivity within fronto-cerebellar networks are found in ADHD 10. Thus, it does not come as a surprise that the processing of event duration is impaired in ADHD. Owing to these difficulties in encoding and producing single durations, one may conclude that children with ADHD have a poor appraisal of the timing of events altogether. This conclusion may be premature, though. Children with ADHD might still be able to treat durations when embedded in a rhythmic context, by benefitting from its predictable temporal structure (i.e., by tracking the beat). Typically, durations can be processed more easily by the healthy brain when they form a rhythmic structure 11, 12. The mechanism underlying beat tracking is