B3650 - LATERALCOG - Typical and atypical development of laterality - 09/11/2020

B number: 
Principal applicant name: 
SEGOND Hervé | Université de Strasbourg (FRANCE)
Title of project: 
LATERALCOG - Typical and atypical development of laterality
Proposal summary: 

The scientific literature provides several elements in favor of the existence of a link 1. between the fetal position at the end of gestation and the development of laterality, on the one hand; 2.between the type of fetal positioning (cephalic vs. breech) and developmental disorders of laterality and interhemispheric communications involved in cognitive functioning, on the other hand (cf. for review Güntürkün, & Ocklenburg, 2017 ). However, a lack of consensus remains today as to the nature of the relationship between the lateralization degree and cognitive development. Some theoretical positions consider that cognitive deficits are noted in individuals whose laterality is weakly established, in other words ambidextrous, while others consider ambilaterality as an advantage both in terms of language and visuospatial abilities (Boles & Barth , 2011; Chiarello, Welcome, Halderman, & Leonard, 2009; Johnston, Nicholls, Shah, & Shields, 2009). Innovatively, we suggest that this lack of consensus could be attributed to the existence of two distinct causes of ambidexterity with different developmental consequences.

Impact of research: 
The development of knowledge in this field constitutes a major societal issue, given the evocation in the scientific literature of the frequent belonging of "laterality disorders" to the clinical picture of many developmental and learning disorders in children (Kershner, 2019; Penolazzi, Spironelli, Vio & Angrilli, 2006; Xu, 2014), disorders that are most often diagnosed too late, during the first school learning, without allowing us to have a precise perception of the nature of these laterality disorders. This issue is all the more important given that these laterality disorders affect a large part of the population in vulnerable situations, since they are not only associated with disturbances in oral and written language (including developmental dyslexia, to which we are concerned, which concerns 6 to 15% of school-age children, dysgraphia, dysorthography, dysphasia and language delay), but also intellectual deficit, psychoses (e.g. schizophrenia), neuro-developmental disorders such as autism (affecting 1 in 150 people in France, according to the High Autority of Health, 2017), epilepsy, as well as deviant behavior. These laterality disorders could even appear as an interesting way of research in the determination of the etiological factors of the Coordination Acquisition Disorders (CAD) or Developmental Coordination Disorders (DCD), also called developmental dyspraxia (Gérard and al., 2005), resulting in early impairment of postural control (static and dynamic balance disorders), coordination and motor learning (lack of tonic regulation, slowness, imprecision, difficulties in relation with novelty, writing impairment), whose co-occurrence with specific language and reading disorders is noted in ± 60% of DCD cases (Vaivre-Douret et al., 2011). The investigation of the links between laterality in development and dyslexia is also part of the incentives of the various calls for scientific projects aimed at understanding the mechanisms at play in the late expression of lasting disorders (such as dyslexia constellation). In addition, the developmental consequences of breech birth would provide a very important source of information for our partners in obstetric hospital services, with a view to guide the evolution of childbirth practices (births by caesarean section vs. routes natural).
Date proposal received: 
Thursday, 5 November, 2020
Date proposal approved: 
Monday, 9 November, 2020
Mental health - Psychology, Psychiatry, Cognition, - Developmental disorders - autism - Cognitive impairment - Learning difficulty e.g. dyslexia - Pregnancy - e.g. postnatal depression, birth outcomes... - Speech/language problem - Coordination Development Disorder , - Qualitative study -Statistical methods, - Birth outcomes - e.g. state of the neonate, presentation during pregnancy, presentation at onset of labor and at delivery - Method of delivery - Cognition - cognitive function - Development - Handedness - Intelligence - memory - Mothers - maternal age, obstetrics - Siblings - Speech and language - Balance - Laterality