School of Psychology, University of Newcastle Callaghan, NSW, Australia ; Priority Research Centre for Translational Neuroscience and Mental Health Research, University of Newcastle Callaghan, NSW, Australia ; Schizophrenia Research Institute Darlinghurst, NSW, Australia.
School of Psychology, University of Newcastle Callaghan, NSW, Australia ; Priority Research Centre for Translational Neuroscience and Mental Health Research, University of Newcastle Callaghan, NSW, Australia.
Front Neurosci. 2014 Jun 25;8:180. doi: 10.3389/fnins.2014.00180. eCollection 2014.
Pattern learning facilitates prediction about upcoming events. Within the auditory system such predictions can be studied by examining effects on a component of the auditory-evoked potential known as mismatch negativity (MMN). MMN is elicited when sound does not conform to the characteristics inferred from statistical probabilities derived from the recent past. Stable patterning in sequences elevates confidence in automatically generated perceptual inferences about what sound should come next and when. MMN amplitude should be larger when sequence is highly stable compared to when it is more volatile. This expectation has been tested using a multi-timescale paradigm. In this study, two sounds of different duration alternate roles as a predictable repetitive "standard" and rare MMN-eliciting "deviation." The paradigm consists of sound sequences that differ in the rate at which the roles of two tones alternate, varying from slowly changing (high stability) to rapidly alternating (low stability). Previous studies using this paradigm discovered a "primacy bias" affecting how stability in patterning impacts MMN amplitude. The primacy bias refers to the observation that the effect of longer-term stability within sequences only appears to impact MMN to the sound first encountered as deviant (the sound that is rare when the sequence commences). This study determines whether this order-driven bias generalizes to sequences that contain two tones differing in pitch. By manipulating (within-subjects) the order in which sounds are encountered as deviants the data demonstrate the two defining characteristics of primacy bias: (1) sequence stability only ever impacts MMN amplitude to the first-deviant sound; and (2) within higher stability sequences, MMN is significantly larger when a sound is the first compared to when it is the second deviant. The results are consistent with a general order-driven bias exerting modulating effects on MMN amplitude over a longer timescale.
模式学习有助于预测即将发生的事件。在听觉系统中，可以通过检查称为失匹配负波（MMN）的听觉诱发电位成分的影响来研究这种预测。当声音不符合从最近过去的统计概率中推断出的特征时，就会产生 MMN。序列中的稳定模式会提高对自动生成的关于下一个声音及其出现时间的感知推断的信心。与序列更不稳定时相比，序列更稳定时 MMN 幅度应该更大。这一期望已通过多时间尺度范式进行了测试。在这项研究中，两种不同持续时间的声音交替作为可预测的重复“标准”和罕见的 MMN 诱发“偏差”。该范式由声音序列组成，这些序列在两种音调的角色交替的速度上有所不同，从缓慢变化（高稳定性）到快速交替（低稳定性）。使用这种范式的先前研究发现了一种“优先偏见”，影响了模式稳定性对 MMN 幅度的影响。优先偏见是指这样一种观察结果，即在序列中较长时间稳定性的影响似乎仅对作为偏差首次遇到的声音（即序列开始时罕见的声音）的 MMN 产生影响。本研究确定这种顺序驱动的偏差是否适用于包含两个音调不同的音调的序列。通过（在被试内）操纵声音作为偏差出现的顺序，数据证明了优先偏见的两个定义特征：（1）序列稳定性仅对第一个偏差声音的 MMN 幅度产生影响；（2）在较高稳定性序列中，当声音是第一个偏差时，MMN 明显大于第二个偏差时。结果与一般的顺序驱动偏差一致，该偏差在较长的时间尺度上对 MMN 幅度产生调制作用。
Zotero 插件
