Abstract:
A previous study we reported in this journal suggested that left and right-handers may differ in their patterns of lateralization for different language tasks (Woodhead et al. 2019 R. Soc. Open Sci. 6, 181801. (doi:10.1098/rsos.181801)). However, it had too few left-handers (N = 7) to reach firm conclusions. For this update paper, further participants were added to the sample to create separate groups of left- (N = 31) and right-handers (N = 43). Two hypotheses were tested: (1) that lateralization would be weaker at the group level in left-than right-handers; and (2) that left-handers would show weaker covariance in lateralization between tasks, supporting a two-factor model. All participants performed the same protocol as in our previous paper: lateralization was measured using functional transcranial Doppler sonography during six different language tasks, on two separate testing sessions. The results supported hypothesis 1, with significant differences in laterality between groups for four out of six tasks. For hypothesis 2, structural equation modelling showed that there was stronger evidence for a two-factor model in left than right-handers; furthermore, examination of the factor loadings suggested that the pattern of laterality across tasks may also differ between handedness groups. These results expand on what is known about the differences in laterality between left- and right-handers.
摘要:
我们在本杂志上报道的先前研究表明,左撇子和右撇子在不同语言任务的偏侧化模式上可能有所不同(Woodhead等人。2019年R.Soc。打开Sci。6,181801年。(数据来源:10.1098/rsos.181801))。然而,它的左撇子太少了(N=7),无法得出坚定的结论。对于这篇更新论文,在样本中加入更多参与者,分别创建左撇子组(N=31)和右撇子组(N=43).对两个假设进行了测试:(1)左撇子在组水平上的侧向化比右撇子要弱;(2)左撇子在任务之间的侧向化中表现出较弱的协方差,支持双因素模型。所有参与者执行与我们之前的论文相同的协议:在六种不同的语言任务中使用功能性经颅多普勒超声检查测量偏侧化,在两个单独的测试会议上。结果支持假设1,在六个任务中的四个任务中,小组之间的侧向性存在显着差异。对于假设2,结构方程模型表明,左撇子的双因素模型比右撇子有更强的证据;此外,对因子载荷的检查表明,不同任务之间的侧向性模式也可能有所不同。这些结果扩展了关于左撇子和右撇子之间侧向性差异的已知信息。