Variability in lateralised blood flow response to language is associated with language development in children aged 1–5 years

Abstract

The developmental trajectory of language lateralisation over the preschool years is unclear. We explored the relationship between lateralisation of cerebral blood flow velocity response to object naming and cognitive performance in children aged 1-5 years. Functional transcranial Doppler ultrasound was used to record blood flow velocity bilaterally from middle cerebral arteries during a naming task in 58 children (59% male). At group level, the Lateralisation Index (LI) revealed a greater relative increase in cerebral blood flow velocity within the left as compared to right middle cerebral artery. After controlling for maternal IQ, left-lateralised children displayed lower expressive language scores compared to right- and bi-lateralised children, and reduced variability in LI. Supporting this, greater variability in lateralised response, rather than mean response, was indicative of greater expressive language ability. Findings suggest that a delayed establishment of language specialisation is associated with better language ability in the preschool years.

What Box: A task for assessing language lateralization in young children

“…The 'What Box' task follows from this literature as a procedure to elicit covert or overt language production in young children. Here we build upon a previous report of the task (Kohler et al, 2015), providing a detailed methodology for the presentation and administration of the task as well as updated processing and analysis techniques for use with fTCD in young children and older adults. In the adults, What Box was also compared with the gold standard Word Generation task.…”

“…Blood flow velocity was measured using a Doppler ultrasonography device (Doppler-Box™, DWL Elektronische Systeme, Singen, Germany) with a Diamon® headset or elastic headbands to hold 2-MHz transducer probes over the left and right temporal skull windows to insonate the middle cerebral arteries. Seated participants viewed the Psychtoolbox (Brainard, 1997;Pelli, 1997 Keage et al, 2015;Kohler et al, 2015).…”

The Need for a Valid Theory of Dyslexia

“…This research focus has led to a resurgence of interest in variations of the traditional notion [4] that dyslexia may be related to atypical interhemispheric processing between the left and right cerebral hemispheres [5,6]. Specifically, in findings that have been replicated, two underdeveloped brain networking regions appear to be centrally involved in the disorder: (1) left arcuate fasciculous, which is the direct white matter route connecting Broca's and Wernicke's territories in the left hemisphere [7][8][9][10]; and (2) the posterior region of the corpus callosum, which drives the lateralization process and interconnects the bilateral parietal cortices with frontostriatal projection tracts, supporting top-down cognitive control of behavior [3,11].…”

Cerebral laterality of writing in right‐ and left‐handers: A functional transcranial Doppler ultrasound study

“…FTCD is an efficient and reliable alternative to fMRI for the study of functional cerebral lateralization (Bishop et al, 2009). It is non‐invasive and relatively inexpensive and is easily applied to individuals of all ages, starting from 1‐year‐olds (Kohler et al, 2015) up to 75‐year‐olds (Keage et al, 2015), in large cohorts (Deppe et al, 2000), in longitudinal studies (Cuadrado et al, 1999) and in follow‐up assessment (Lohmann et al, 2005). Results obtained with the use of fTCD are highly reproducible (Knecht, Deppe, Ringelstein, et al, 1998) and language laterality assessments performed using fTCD have very good agreement with the gold standard method in the field, the intra‐carotid amobarbital procedure (Wada test; Knake et al, 2003; Knecht, Deppe, Ebner, et al, 1998).…”