Effect of initiation-inhibition and handedness on the patterns of the P50 event-related potential component: a low resolution electromagnetic tomography study.

Ion N Beratis,Christos N Capsalis,Argiro E Maganioti,Andreas Rabavilas,Eleni D Nanou,George N Papadimitriou,Chrissanthi Hountala,Charalabos Papageorgiou

doi:10.1186/1744-9081-5-51

Abstract

BackgroundRecent research recognizes the association between handedness, linguistic processes and cerebral networks subserving executive functioning, but the nature of this association remains unclear. Since the P50 event related potential (ERP) is considered to reflect thalamocortical processes in association with working memory (WM) operation the present study focuses on P50 patterns elicited during the performance of a linguistic related executive functioning test in right- and left-handers.MethodsIn 64 young adults with a high educational level (33 left-handed) the P50 event-related potential was recorded while performing the initiation and inhibition condition of a modified version of the Hayling Sentence Completion test adjusted to induce WM. The manual preference of the participants was evaluated with the use of the Edinburgh Handedness Inventory (EHI).ResultsP50 showed greater amplitudes in left- than in right-handers, mainly in frontal leads, in the initiation condition. Reduced amplitudes in inhibition compared to initiation condition were observed in left-handers. Low Resolution Electromagnetic Tomography (LORETA) analysis showed lower frontal lobe activation in the inhibition than in the initiation condition in both right- and left-handers. Also, LORETA yielded that right-handers exhibited greater activation in the inhibition condition than left-handers. Additionally, LORETA showed assymetrical hemispheric activation patterns in right-handers, in contrast to symmetrical patterns observed in left-handers. Higher P50 amplitudes were recorded in right-hemisphere of right-handers in the initiation condition.ConclusionBrain activation, especially the one closely related to thalamocortical function, elicited during WM operation involving initiation and inhibition processes appears to be related to handedness.

Highlights

Recent research recognizes the association between handedness, linguistic processes and cerebral networks subserving executive functioning, but the nature of this association remains unclear
The multivariale analyses of variance (MANOVA) model applied, with the amplitudes of the 26 electrodes as dependent variables, and handedness, Hayling condition, and their interaction as independent factors showed a significant effect of the interaction of Hayling condition and handedness on the amplitudes of the electrodes [F(26,93) = 1.711 p = 0.033]
The findings of this study show greater P50 event related potential (ERP) amplitudes in the left- than in the right-handers in the initiation condition, with the most profound differences located at frontal leads, as well as reduced amplitudes in the inhibition than in the initiation condition, in the left-handed group

Summary

Introduction

Recent research recognizes the association between handedness, linguistic processes and cerebral networks subserving executive functioning, but the nature of this association remains unclear. Since the P50 event related potential (ERP) is considered to reflect thalamocortical processes in association with working memory (WM) operation the present study focuses on P50 patterns elicited during the performance of a linguistic related executive functioning test in right- and left-handers. The study of handedness is of interest because of its association with the lateralization of hemispheric function and the presence of data that indicate functional differences between left- and right-handers [1,2,3]. There is not complete agreement between the degree of right- and left-sided dominance of motor functions and lateralization of cognitive functions, a relationship between hemispheric asymmetry for components of cognition and handedness is evident. Nowicka et al [7] by using visually presented words found differences in the ERP recordings between right- and left-handed women, observation which indicates that the encoding of new and repeated verbal information is differently lateralized in reference to handedness

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