Exploration of electroencephalographic signatures of non-dominant handwriting task

Abstract

Background: Handwritten language is one of the key learned expertises of the human brain and preferred modes for long-distance communication. The dexterity and hand dominance in written language are well-known phenomenon. Normally, we are accustomed to writing with one hand only. Literature suggests that the dual task of attention interferes with the performance of one task and/or the other, as these tasks use the same attentional resources. Aim: The aim of this study was to investigate the quantitative electroencephalographic (EEG) correlates of non-dominant handwriting (NDHW) as an attentionally demanding task. Materials and Methods: We conducted a study on 35 male native Hindi speakers, well accustomed to reading and writing. The intervention consisted of 5-min writing with the DHW and NDHW with concurrent EEG recording. The EEG electrodes were applied according to the 10–20 international system of electrode placement. EEG signals were analysed offline. The outcome measures were fast Fourier transform transformed absolute power in delta (1–4 Hz), theta (4–8 Hz), alpha (8–14 Hz), beta (14–30 Hz) and gamma (30–50 Hz) frequency bands at 19 electrode positions. Medians of 10 epochs from artefact-free regions of EEG during NDHW and DHW were statistically analysed. Results: The task of NDHW was associated with decreased absolute powers in frontal and occipital leads mainly in delta and theta frequency bands and at frontocentral leads in the alpha band. Absolute powers in the beta frequency band were increased mainly at frontal and decreased posteriorly, while there was a generalised increase in gamma-band power. Conclusions: NDHW task as compared to the DHW task has distinct EEG correlates suggestive of a stressed attentive mental state.

Keywords

• fast fourier transform
• quantitative electroencephalography
• writing task
• stressed attentive mental state