Investigating the neural architecture of handedness

Frontiers in Psychology

Sebastian Ocklenburg¹ 

关键词: handedness;    genetics;    cortex;    ontogenesis;    endophenotype;    motor cortex;    MRI imaging;   

DOI  :  10.3389/fpsyg.2015.00148

学科分类：心理学（综合）

来源: Frontiers

【 摘 要 】

When we look at our hands, outwardly they look remarkably similar to each other—and the bones, muscles and nerves within the two hands are equally symmetric. Way before the advent of modern neuroimaging, this fact led researchers to the conclusion that the striking preference most people show in using one hand over the other to conduct fine motor tasks must originate somewhere in the cerebral cortex and not in the peripheral nervous system (McManus, 1996). However, the question of where exactly has been proven surprisingly hard to answer, even with advanced neuroimaging methods. Functionally, the cortical correlates of handedness have been investigated by different authors using fMRI (functional magnetic resonance imaging), for example by measuring brain activity in motor areas of left- and right-handers during unilateral or bilateral finger or hand movements (e.g., Gut et al., 2007; Klöppel et al., 2007; Grabowska et al., 2012). In addition, several studies were aimed at identifying the macrostructural correlates of left-and right-handedness in the cerebral cortex (e.g., regarding the volume of different gray matter brain areas), with mixed results. While some authors found significant structural differences between left and right-handers, e.g., in the precentral gyrus and sulcus (Amunts et al., 1996; Foundas et al., 1998), the planum temporale (Hervé et al., 2006) and Broca's area (Powell et al., 2012a), others could not identify any macrostructural correlates of handedness (e.g., Good et al., 2001). These somewhat ambiguous results might in part be due to sample characteristics, since especially in studies with a small number of left-handers, individual anatomical properties in this group might have had a disproportionally large impact on the overall effect.

【 授权许可】

CC BY