Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom SE5 8AF.
Center for Neural Science, New York University, New York, NY 10003.
eNeuro. 2019 Apr 15;6(2). doi: 10.1523/ENEURO.0274-18.2018. eCollection 2019 Mar-Apr.
Language difficulties have been reported in children and adolescents who were born very preterm (<32 weeks' gestation) and associated with an atypical lateralization of language processing, i.e., increased right-hemispheric engagement. This study used functional magnetic resonance imaging (fMRI) and spherical deconvolution tractography to study the hemodynamic responses associated with verbal fluency processing (easy and hard letter trials) and verbal fluency-related white matter fiber tracts in 64 very preterm born adults and 36 adult controls (mean age: 30 years). Tractography of the arcuate fasciculus (AF) and frontal aslant tract (FAT) was performed. Tracts were quantified in terms of mean volume, hindrance modulated orientational anisotropy, and lateralization, assessed using a laterality index (LI) to indicate hemispheric dominance. During verbal fluency fMRI, very preterm participants displayed decreased hemodynamic response suppression in both the Easy > Rest and Hard > Rest conditions, compared to controls, in superior temporal gyrus (STG), insula, thalamus, and sensorimotor cortex, particularly in the right hemisphere. At the whole-group level, decreased hemodynamic response suppression in the right sensorimotor cortex was associated with worse on-line performance on the hard letter trials. Increased left-laterality in the AF was present alongside increased right hemispheric hemodynamic response suppression in controls. When only right-handed participants were considered, decreased hemodynamic response suppression in the right STG during hard letter trials was related to weaker left and right FAT white matter integrity in the preterm group only. These results show that verbal fluency is affected by altered functional lateralization in adults who were born very preterm.
语言困难在极早产儿（<32 周妊娠）中已有报道，并与语言处理的非典型侧化有关，即右半球参与增加。本研究使用功能磁共振成像（fMRI）和球型解卷积轨迹技术，研究了与言语流畅性处理（简单和困难字母试验）相关的血流动力学反应，以及 64 名极早产儿和 36 名成人对照组（平均年龄：30 岁）的言语流畅性相关白质纤维束。进行了弓状束（AF）和额斜束（FAT）的轨迹分析。根据平均体积、阻碍调制各向异性和侧化来量化束，使用侧化指数（LI）来评估半球优势。在言语流畅性 fMRI 中，与对照组相比，极早产儿在颞上回（STG）、岛叶、丘脑和感觉运动皮层的 Easy > Rest 和 Hard > Rest 条件下，血流动力学反应抑制均降低，尤其是在右半球。在全组水平上，右感觉运动皮层血流动力学反应抑制降低与困难字母试验在线表现较差相关。在对照组中，AF 的左侧化增加伴随着右半球血流动力学反应抑制增加。当仅考虑右利手参与者时，在困难字母试验中右 STG 中血流动力学反应抑制降低与早产儿组中较弱的左、右 FAT 白质完整性相关。这些结果表明，言语流畅性受极早产儿出生的成年人功能性侧化改变的影响。
