Fisher Alison E, Barnes Gareth R, Hillebrand Arjan, Holliday Ian E, Witton Caroline, Richards Ian L
The Wellcome Trust Laboratory for MEG Studies, Neurosciences Research Institute, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
Brain Res. 2006 Mar 10;1077(1):90-8. doi: 10.1016/j.brainres.2005.12.121. Epub 2006 Feb 20.
Evidence of abnormalities in the perception of rapidly presented sounds in dyslexia has been interpreted as evidence of a prolonged time window within which sounds can influence the perception of temporally surrounding sounds. We recorded the magnetic mismatch negativity (MMNm) to infrequent tone omissions in a group of six dyslexic adults and six IQ and age-matched controls. An MMNm is only elicited in response to a complete stimulus omission when successive inputs fall within the temporal window of integration (stimulus onset asynchrony (SOA) approximately 160 ms). No MMNm responses were recorded in either experimental group when stimuli were presented at SOAs falling just outside the temporal window of integration (SOA = 175 ms). However, while presentation rates of 100 ms resulted in MMNm responses for all control participants, the same stimulus omissions elicited an MMNm response in only one of the six dyslexic participants. These results cannot support the hypothesis of a prolonged time window of integration, but rather indicate auditory grouping deficits in the dyslexic population.
阅读障碍患者对快速呈现声音的感知异常证据，被解释为存在一个延长的时间窗口，在此窗口内声音能够影响对时间上相邻声音的感知。我们记录了一组6名成年阅读障碍患者以及6名智商和年龄匹配的对照组对罕见音调遗漏的磁失配负波（MMNm）。只有当连续输入落在整合时间窗口内（刺激起始异步（SOA）约为160毫秒），对完全刺激遗漏做出反应时才会引出MMNm。当刺激以刚好超出整合时间窗口的SOA（SOA = 175毫秒）呈现时，两个实验组均未记录到MMNm反应。然而，虽然100毫秒的呈现速率使所有对照参与者都出现了MMNm反应，但相同的刺激遗漏仅在6名阅读障碍参与者中的1人身上引出了MMNm反应。这些结果不支持整合时间窗口延长的假设，而是表明阅读障碍人群存在听觉分组缺陷。
