Language production is associated with a distinct lateralised pattern of brain activation biased toward the left cerebral hemisphere. This also applies to writing. It has also been shown to be modulated by handedness, with less pronounced lateralisation in left-handers. However, in recent decades the use of handwriting has declined significantly while the use of smartphones has exploded. To date, no study has explored whether the same neural correlates of written language production found for handwriting also hold for typing on a smartphone.

 

In the current study, Samsouris et al. (2023) will use functional transcranial Doppler ultrasound (fTCD) to measure blood flow velocity within cerebral hemispheres to investigate this question. This technique is particularly suited for this purpose because it provides better control for the movement confounds associated with a writing task and the technical challenges of using a smart device than other neuroimaging techniques like fMRI or M/EEG. The authors hypothesise that there will be no difference in left cerebral lateralisation for handwriting and typing on a smartphone. They also expect to replicate previous findings of weaker lateralisation in left-handers in written language production when typing on a smartphone. To isolate the effect of written language production, both these conditions will be corrected for their corresponding motor component using control conditions without a linguistic component.

 

The Stage 1 manuscript was evaluated over 6 rounds of in-depth review by the recommender and two expert reviewers, before issuing in-principle acceptance.

 

URL to the preregistered Stage 1 protocol: https://osf.io/j7egz
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.
 
List of eligible PCI RR-friendly journals:
 

 

1. Samsouris, C., Badcock, N. A., Vlachos, F., & Papadatou-Pastou, M. (2023). Cerebral laterality as assessed by functional transcranial Doppler ultrasound in left-and right-handers: A comparison between handwriting and writing using a smartphone. In principle acceptance of Version 7 by Peer Community in Registered Reports. https://osf.io/j7egz

While cerebral lateralisation for oral language is well-characterised, cerebral lateralisation for written language is much less well-understood. In this study, Papadopoulou et al. (2022) will use functional transcranial Doppler ultrasonography to assess lateralisation for written language in 7- to 9-year-old children at risk for dyslexia and neurotypical children. They will use tasks that assess efficiency in reading and writing names as well as speed and fluency in writing. The findings of this manuscript will highlight whether children with dyslexia showed atypical lateralisation for language in a written task. In addition, the authors plan to explore the correlation between lateralisation and writing competence. 

 

The Stage 1 manuscript was evaluated over two rounds of in-depth review. Based on the edits made to the manuscript, and detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/u54tk (under temporary private embargo)
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA. 
 
List of eligible PCI RR-friendly journals:
 

 

References
 

1. Papadopoulou, A.-K., Vlachos, F., Pervanidou, P., Anesiadou, S., Antoniou, F., Phylactou, P., Badcock, N.A. & Papadatou-Pastou, M. (2022). Cerebral lateralization of writing in students at risk for dyslexia using functional Transcranial Doppler ultrasonography, in principle acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/u54tk (under temporary private embargo)