Studies of brain lateralization in individuals with non-specific intellectual disability and Down syndrome suggest atypical brain lateralization to speech perception. According to the biological dissociation model, the right hemisphere (RH) mediates speech perception and the left hemisphere (LH) mediates motor control in Down syndrome. The current study aimed to test, for the first time, brain lateralization in both non-specific intellectual disability and Down syndrome, compared to individuals with typical development. Furthermore, bilateral word presentation was utilized to assess interhemispheric communication. Twenty adults with non-specific intellectual disability, 14 adults with Down syndrome, and 30 adults with typical development participated in the study. Participants in the non-specific intellectual disability and Down syndrome groups were trained to perform the task prior to the experiment. The results showed that whereas hemispheric lateralization did not differ between individuals with non-specific intellectual disability and typical development, individuals with DS showed reduced brain lateralization in comparison to adults with typical development. All three groups showed no significant difference between words presented to the LH and bilaterally. Our results also show that individuals with intellectual disabilities can benefit from training programmes and that they may perform equally as fast as their typically developing peers.

中文翻译：

---

在患有和不患有唐氏综合症的智力障碍成年人中，在接受训练后使用划分视野技术进行词汇决策。

对非特异性智力障碍和唐氏综合症患者的大脑偏侧化的研究表明，非典型的大脑偏侧化为语音感知。根据生物学解离模型，唐氏综合症中，右半球（RH）介导语音感知，左半球（LH）介导运动控制。当前的研究旨在首次测试非典型智力障碍和唐氏综合症与具有典型发展能力的个体相比的大脑偏侧化。此外，双边的单词呈现被用来评估半球之间的交流。20名非特异性智力障碍的成年人，14名唐氏综合症的成年人和30名典型发育的成年人参加了这项研究。在实验之前，对非特定性智力障碍和唐氏综合症组的参与者进行了培训，以执行任务。结果表明，尽管具有非特异性智力障碍和典型发育的个体之间半球偏侧化没有差异，但与具有典型发育的成年人相比，DS个体的脑偏侧化程度降低。这三组在向LH和双方提交的单词之间均没有显着差异。我们的研究结果还表明，智障人士可以从培训计划中受益，他们的表现可以与通常发展的同龄人一样快。结果显示，尽管具有非特异性智力障碍和典型发育的个体之间半球偏侧化没有差异，但与具有典型发育的成年人相比，DS个体显示出脑偏侧化程度降低。这三组在向LH和双方提交的单词之间均没有显着差异。我们的结果还表明，智障人士可以从培训计划中受益，并且他们的表现可以与通常发展的同龄人一样快。结果显示，尽管具有非特异性智力障碍和典型发育的个体之间半球偏侧化没有差异，但与具有典型发育的成年人相比，DS个体显示出脑偏侧化程度降低。这三组在向LH和双方提交的单词之间均没有显着差异。我们的研究结果还表明，智障人士可以从培训计划中受益，他们的表现可以与通常发展的同龄人一样快。