Background Protocol Analysis, Results & Discussion Despite a lower general performance, DCD children presented a relative intact motor learning of a rhythmic sequence. In both groups, the accuracy and the stability of a sensori-motor sequence was increased with auditory vs visual stimulations. However, DCD children present more errors when auditory stimulations were removed suggesting their auditory modality dependency. This increase correlated with cortical thickness of insula audit area suggesting that this cortical structure inform about the auditory sequence memory. Participants 20 typically developing (TD) and 12 DCD right-handed children (8-12 years old) Behavioural analysis were performed with circular statistics (Berens, 2009): • It is still unclear to what extent children with DCD present a deficit in procedural learning We expect that DCD children present a learning deficit than children without DCD • The auditory modality actives more a part of striatum than visual modality (Witt et al., 2008). This subcortical structure is supposed to dysfunction in DCD (Nicolson & Fawcett 2011; Bo et al., 2013) We expect that DCD present a learning deficit with auditory stimuli than children without DCD • Studies provide evidence of distinct patterns of cortical thinning of DCD and control children (Langevin et al. 2015) We expect that learning deficit is correlated with cortical structure in DCD REFERENCES: Berens (2009) Journal of Statistical Software, 31, 1-21 // Bo et al. (2013) Research in Developmental Disabilities, 2047-2055 // Langevin et al. (2015) Developmental Medicine and Child Neurology, 57, 257-264 // Nicolson & Fawcett (2011) Cortex, 47, 117-127 // Witt et al. (2008) Neuroimage, 42, 343-356. Cortical brain structure predicts memory of auditory vs visual rhythmic sequences in Children with and without Developmental Coordination Disorder (DCD) Blais M 1 , Péran P 1 , Chauveau N 1 , Biotteau M 1,2 , Maziero S 1,2 , Jucla M 2 , Albaret J-M 1 , Chaix Y 1,3 , Tallet J 1 1 Toulouse NeuroImaging Center, Toulouse University, Inserm, UPS, France 2 Octogone-Lordat, Toulouse University, UT2J, Toulouse, France 3 Children’s Hospital, CHU Purpan, Toulouse, France Experimental task Participants had to learn 2 non-isochronous rhythmic sequences by tapping with their right index finger on a keyboard in synchronization with auditory (one sequence) and visual stimulations (one sequence). 2 Sequences on 2 Modalities (Auditory and Visual) Fig.1. Illustration of the 2 sequences in the 2 modalities For each sequence (one by modality), each participant practiced 30 trials (10 blocs of 3 trials). After each trial, a visual feedback of the performance was given. At the end of the practice session, 3 trials without stimulation were performed to test the immediate retention (IMM). Finally, all children (excepted 1 DCD children) performed a magnetic resonance imaging. Protocol → LEARNING: ANOVA Group (2) x Modality (2) x Practice (10) on angular vector, vector length and error → RETENTION: ANOVA Group (2) x Modality (2) x Retention (2) on angular vector, vector length and error → Correlation between significant behavioural results and cortical thickness Fig. 2. Representation of responses (red circles) for one trial that yield a resultant vector (blue) Sequence 1, Auditory modality Sequence 2, Auditory modality 1650 Sequence 1, Visual modality Sequence 2, Visual modality → Angular vector (accuracy) corresponds to the time difference between the tap responses and the apparition of the stimulations. → Vector Length (stability) varying between 0 and 1. → Number of Errors corresponds to omissions and additional taps • PRACTICE: Higher decrease of angular vector (Fig 4), error (Fig 6a) and increase of vector length (Fig 5) from B1 to B10 for auditory than visual stimulations Fig.4 : Mean of the angular vector (± SE) for Visual and Auditory stimulations irrespective of the Group • Significant correlation between the difference of error from IMM to B10 of DCD group for auditory modality and cortical thickness of insula audit (Fig 6b) Fig.6a : Mean of the error (± SE) fof TD and DCD group or Visual and Auditory stimulations. b. Correlation between the difference of error from IMM – B10 of TD and DCD group for auditory modality and cortical thickness of insula audit • RETENTION: Higher increase of angular vector and decrease of vector length from B10 to IMM irrespective of the group and modality. 1650 900 900 500 500 900 900 900 1650 900 900 1650 1650 900 900 900 1650 1650 1650 900 900 500 500 900 900 900 1650 900 900 1650 1650 900 900 900 1650 900 900 1650 Stimulus → Cortical thickness of 11 regions of interest from MRI T1 Fig.5 : Mean of the vector length (± SE) for Visual and Auditory stimulations irrespective of the Group Fig. 3. Exemple of a T1 of one participant and illustration of the cortical thickness Neural analysis were performed with Corthizon Toolbox : • Higher increase of number of errors from B10 to IMM of DCD group for Auditory modality (Fig 6a)