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Single-trial analysis and its applications in EEG and simultaneous EEG-fMRI studies.

機(jī)譯：單次試驗(yàn)分析及其在腦電圖和同時(shí)進(jìn)行的腦電圖功能磁共振成像研究中的應(yīng)用。

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摘要

Electrophysiological recordings such as human electroencephalogram (EEG) and monkey local field potentials (LFP) are traditionally thought to be comprised of a deterministic event-related potential (ERP) plus a task-irrelevant random noise. However, evidence has long suggested that the ERP waveform can vary from trial to trial. Such trial-to-trial variability often bears important information about the dynamics of the underlying cognitive processes. With recent advancements in single-trial analysis methods, we seek to explore in this dissertation the dynamics of cognitive processes underlying higher-level cognitive functions including visual attention, emotional processing, and classical conditioning.;First, we applied a recently developed single-trial analysis method, Analysis of Single-trial ERP and Ongoing signals (ASEO), to study the trial-to-trial temporal dynamics of sensory facilitation during classical aversive conditioning. Estimating the amplitude of the P1 component elicited by the conditioned stimuli (CSs), we found that P1 amplitude fluctuations within the acquisition session followed three distinct phases. Further, the effects of sensory facilitation toward the CS predicting aversive outcomes, compared to the CS predicting neutral outcomes, were manifested by differences in the rate of P1 amplitude changes within each phase. Second, we investigated brain structures involved in the generation and modulation of the late positive potential (LPP) during emotional processing. Correlating single-trial LPP amplitude with the simultaneously recorded blood-oxygen-level-dependent (BOLD) activity, we found that regions contributing to scalp-recorded LPP included the visual cortices and emotional processing structures. Moreover, the degree of contribution to scalp LPP from these structures was valence specific. Finally, we investigated brain areas contributing to the attentional modulation of alpha (8--12 Hz) in spatial visual attention. Our results suggest that the intraparietal sulcus, a core region within the frontoparietal attention network, modulates the trial-to-trial alpha desynchronization. Further, we found a positive correlation between alpha lateralization and BOLD in dorsal anterior cingulate cortex (dACC), suggesting a role for dACC in facilitating the attentional set via executive influences over attentional control systems.;In conclusion, the results suggest that trial-to-trial variability is an important aspect of the cognitive process. Exploring such variability can gain us valuable insights into the neuronal mechanisms of higher-level cognitive processes.
機(jī)譯：傳統(tǒng)上認(rèn)為，諸如人腦電圖（EEG）和猴子局部場電勢（LFP）的電生理記錄包括確定性事件相關(guān)電勢（ERP）以及與任務(wù)無關(guān)的隨機(jī)噪聲。但是，長期以來有證據(jù)表明，每個(gè)試驗(yàn)的ERP波形可能會有所不同。這種試驗(yàn)間的差異常常帶有有關(guān)潛在認(rèn)知過程動力學(xué)的重要信息。隨著單項(xiàng)試驗(yàn)分析方法的最新發(fā)展，我們試圖在本文中探索基于高級認(rèn)知功能（包括視覺注意力，情緒加工和經(jīng)典條件）的認(rèn)知過程的動力學(xué)。首先，我們應(yīng)用了最近開發(fā)的單項(xiàng)試驗(yàn)。分析方法，單次嘗試ERP和持續(xù)信號分析（ASEO），以研究經(jīng)典厭惡條件下感覺促進(jìn)的試驗(yàn)到試驗(yàn)的時(shí)間動態(tài)。估計(jì)由條件刺激（CSs）引起的P1分量的振幅，我們發(fā)現(xiàn)在采集會話中P1振幅波動遵循三個(gè)不同的階段。此外，與CS預(yù)測中性結(jié)局相比，對CS預(yù)測厭惡結(jié)局的感覺促進(jìn)作用通過每個(gè)階段內(nèi)P1振幅變化率的差異來體現(xiàn)。其次，我們研究了在情緒加工過程中晚期正電位（LPP）的產(chǎn)生和調(diào)節(jié)所涉及的大腦結(jié)構(gòu)。將單次試驗(yàn)的LPP振幅與同時(shí)記錄的血氧水平依賴性（BOLD）活動相關(guān)聯(lián)，我們發(fā)現(xiàn)有助于頭皮記錄的LPP的區(qū)域包括視覺皮層和情緒處理結(jié)構(gòu)。而且，這些結(jié)構(gòu)對頭皮LPP的貢獻(xiàn)程度是價(jià)特異性的。最后，我們研究了大腦區(qū)域在空間視覺注意中對阿爾法（8--12 Hz）的注意調(diào)制做出的貢獻(xiàn)。我們的結(jié)果表明，頂內(nèi)溝是額頂上注意網(wǎng)絡(luò)內(nèi)的核心區(qū)域，可調(diào)節(jié)試驗(yàn)至試驗(yàn)的α失步。此外，我們發(fā)現(xiàn)背側(cè)前扣帶回皮質(zhì)（dACC）中的alpha側(cè)向化和BOLD之間存在正相關(guān)，這表明dACC在通過對注意力控制系統(tǒng)的執(zhí)行影響來促進(jìn)注意力集中方面發(fā)揮了作用。 -試驗(yàn)變異性是認(rèn)知過程的重要方面。探索這種可變性可以使我們獲得對高級認(rèn)知過程的神經(jīng)元機(jī)制的寶貴見解。

著錄項(xiàng)

  • 作者

    Liu, Yuelu.;

  • 作者單位

    University of Florida.;

  • 授予單位 University of Florida.;
  • 學(xué)科 Engineering Biomedical.
  • 學(xué)位 Ph.D.
  • 年度 2013
  • 頁碼 112 p.
  • 總頁數(shù) 112
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類
  • 關(guān)鍵詞

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