Sensitivity to the temporal structure of rapid sound sequences - An MEG study
Sensitivity to the temporal structure of rapid sound sequences - An MEG study
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DOI：
10.1016/j.neuroimage.2015.01.052
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发表时间：
2015-04-15
期刊：
影响因子：
5.7
通讯作者：
Chait, Maria
中科院分区：
文献类型：
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作者：
Andreou, Lefkothea-Vasiliki;Griffiths, Timothy D.;Chait, Maria
为了探测正在进行的声音序列的时间结构的敏感性，我们测量了MEG的反应，在人类的听众，长音调的pip序列包含各种形式的时间规律性的偏移。如果听众学习序列的时间属性，并形成对即将到来的音调的到达时间的预期，序列偏移应该是可检测的，只要预期的音调未能到达。因此，偏移响应的延迟指示已经获取时间模式的程度。在实验1中，序列是等长的，音调发病间隔（IOI）设置为75，125或225 ms。实验2由非等长的，时间上规则的序列组成，由上述IOI组成。实验3使用与实验2相同的序列，但要求听众监测它们的偶尔频率偏差。偏移响应的延迟的分析表明，（甚至相当简单的）定期序列的时间结构是不精确的序列被忽略时，学习。当信号与行为相关时，由颞叶、顶叶和额叶来源组成的网络支持的模式编码得到了相当大的改善。因此，与在“预警系统”框架的背景下可能预期的相反，时间结构的学习不是自动的，而是受信号的行为相关性的影响。(C)2015作者爱思唯尔公司出版
To probe sensitivity to the time structure of ongoing sound sequences, we measured MEG responses, in human listeners, to the offset of long tone-pip sequences containing various forms of temporal regularity. If listeners learn sequence temporal properties and form expectancies about the arrival time of an upcoming tone, sequence offset should be detectable as soon as an expected tone fails to arrive. Therefore, latencies of offset responses are indicative of the extent to which the temporal pattern has been acquired. In Exp1, sequences were isochronous with tone inter-onset-interval (IOI) set to 75, 125 or 225 ms. Exp2 comprised of non-isochronous, temporally regular sequences, comprised of the IOIs above. Exp3 used the same sequences as Exp2 but listeners were required to monitor them for occasional frequency deviants. Analysis of the latency of offset responses revealed that the temporal structure of (even rather simple) regular sequences is not learnt precisely when the sequences are ignored. Pattern coding, supported by a network of temporal, parietal and frontal sources, improved considerably when the signals were made behaviourally pertinent. Thus, contrary to what might be expected in the context of an 'earlywarning system' framework, learning of temporal structure is not automatic, but affected by the signal's behavioural relevance. (C) 2015 The Authors. Published by Elsevier Inc.