Mugruza-Vassallo Carlos, Potter Douglas
Grupo de Investigación de Computación y Neurociencia Cognitiva, Facultad de Ingeniería y Gestión, Universidad Nacional Tecnológica de Lima Sur - UNTELS, Lima, Perú.
Neuroscience and Development Group, Arts and Science, University of Dundee, Dundee, United Kingdom.
Front Hum Neurosci. 2019 Feb 26;13:39. doi: 10.3389/fnhum.2019.00039. eCollection 2019.
Typically, in an oddball paradigm with two experimental conditions, the longer the time between novels the greater P3a amplitude. Here the research question is: Does an oddball paradigm maintain the greater P3a amplitude under several experimental conditions? An EEG study was carried out with an oddball number parity decision task having four conditions in control and schizophrenic participants. Contrary to previous findings (Gonsalvez and Polich, 2002; Polich, 2007) in control participants, non-correlation was found between the time of a novel (N) stimulus condition to the next novel condition and P3a amplitude. Moreover, with an innovative method for stimulus properties extraction features and EEG analysis, single trial across-subject averaging of participants' data revealed significant correlations ( > 0.3) of stimulus properties (such as probability, frequency, amplitude, and duration) on P300, and even > 0.5 was found when N was an environmental sound in schizophrenic patients. Therefore, stimulus properties are strong markers of some of the features in the P3a wave. Finally, a context analysis of ERP waves across electrodes revealed a consistent modulation in novel appearance for MisMatch Negativity in schizophrenia. A supplementary analysis running linear modeling (LIMO) in EEG was also provided (see Supplementary Material). Therefore, in a multiple condition task: stimulus properties and their temporal properties are strong markers of some of the features in the P300 wave. An interpretation was done based on differences between controls and schizophrenics relate to differences in the operation of implicit memory for stimulus properties and stronger correlations were observed within groups related contextual and episodic processes.
通常，在具有两种实验条件的oddball范式中，新奇刺激之间的时间间隔越长，P3a波幅越大。这里的研究问题是：在几种实验条件下，oddball范式是否能保持更大的P3a波幅？我们对对照组和精神分裂症患者进行了一项脑电图（EEG）研究，采用了具有四种条件的oddball数字奇偶性判断任务。与之前对对照组参与者的研究结果（Gonsalvez和Polich，2002年；Polich，2007年）相反，我们发现新奇（N）刺激条件到下一个新奇条件的时间与P3a波幅之间不存在相关性。此外，通过一种创新的刺激特性提取特征和EEG分析方法，对参与者数据进行单试次跨个体平均后发现，刺激特性（如概率、频率、波幅和持续时间）与P300之间存在显著相关性（>0.3），在精神分裂症患者中，当N为环境声音时，相关性甚至>0.5。因此，刺激特性是P3a波某些特征的强标记物。最后，对跨电极的事件相关电位（ERP）波进行背景分析，发现精神分裂症患者在新奇刺激出现时，失匹配负波（MMN）存在一致的调制。我们还提供了一项在EEG中运行线性建模（LIMO）的补充分析（见补充材料）。因此，在多条件任务中：刺激特性及其时间特性是P3a波某些特征的强标记物。基于对照组和精神分裂症患者之间的差异进行了解释，这些差异与刺激特性的内隐记忆操作差异有关，并且在与情境和情节过程相关的组内观察到更强的相关性。
