Attention Orienting And Executive Control Respectively Studied With Event-related Electroencephalography And A Multi-modality Optical-electrophysiology Method

Attention is an important cognitive function for humans. It is critical for study, life, work and any cognitive process of human beings. Abnormal attention is closely related with many diseases. Thus, it has great significance to investigate the neural correlates of attention.This study focused on two components of attention:orienting and executive control. As to orienting, the influence of visuospatial attention orienting on stimulus processing and the influence of threatening emotion on orienting were investigated with event-related electroencephalography (EEG). Regarding executive control, the neural correlates of executive control was investigated with a multi-modality optical-electrophysiology method combining near-infrared spectroscopy (NIRS) and event-related EEG in a Stroop task. The main research contents and innovation are as follows:(1) The influence of visuospatial attention orienting on stimulus processing was investigated by combining event-related potential (ERP) and event-related oscillation (ERO) analyses. The mean amplitude of P1was more positive for valid stimuli than invalid stimuli. Valid stimuli led to significant power increase in theta, alpha and beta. The power increase in theta for valid stimuli was significantly larger than that for invalid stimuli, which indicates that theta might reflect how much visuospatial attention is allocated. Alpha power increase in the posterior region ipsilateral to the attended position reflects an active suppression mechanism. The attention modulation on beta was similar to alpha, which indicates that beta might reflect a similar mechanism to alpha. These results indicate that visuospatial attention influences the stimulus processing by both facilitating the attended stimuli and inhibiting the unattended stimuli under sustained attention.(2) The attentional bias of threatening emotion relative to pleasant emotion was investigated in an emotional dot probe task by using both ERP and ERO analyses. Emotional cues showed for500ms. The mean amplitude of N1was greater negative for threatening cues than pleasant cues with the most significant effect in the fronto-central region, indicating a processing bias for threat related to the early attention processing. The theta synchronization was stronger for threatening cues than pleasant cues with significant effect in posterior regions, suggesting that the posterior theta synchronization reflects the evaluation of emotional significance of stimuli. Taken together, these results indicate that attention is more oriented toward threatening information and ERP and ERO analyses provide some independent insights into the attentional bias for threatening emotion.(3) The hemodynamic and electrophysiological responses in a color-word matching Stroop task were simultaneously measured by combining NIRS and ERP to study the neural correlates of executive control. There were gender differences in the Stroop effects of response time (Stroop_RT) and late positive complex (Stroop_LPC). The Stroop_LPC was only significant in females. The results show that LPC is associated with additional processing of word meaning, and females conduct more elaborate semantic processing which might contribute to their larger Stroop_RT. The significant N450Stroop effect occurred before the behavioral response to incongruent stimuli, and it was negatively correlated with the oxy-hemoglobin (HbO2) Stroop effect. More specifically, the HbO2Stroop effect in the left prefrontal cortex (PFC) was negatively correlated with the N450Stroop effect during the early phase (440-580ms), while the HbO2Stroop effect in the bilateral PFC was negatively correlated with the N450Stroop effect during the later phase (600-680ms). The results indicate that:(1) there are two stages in N450:conflict detection and resolution;(2) left PFC may be involved in conflict detection and bilateral PFC is engaged in conflict resolution.This study provides insights into the neural correlates of attention orienting and executive control, and gives practical guidance for studying the abnormal attention of diseases.