奖励驱动的双任务加工过程中的分离脑机制：来自ERP的证据

运用事件相关电位技术, 采用分支双任务范式, 探讨在奖励驱动的双任务加工过程中, 第一任务奖励编码和第二任务奖励编码的时间进程及其脑机制。结果发现：双任务的反应时显著大于单任务的反应时; 单任务的N2波幅显著大于双任务条件; 双任务的P3波幅显著大于单任务条件。双任务加工过程中奖励编码的半球效应主要体现在P3上, 且右半球参与第一任务奖励信息的编码, 驱动第一任务; 两半球协同参与第二任务奖励信息的编码, 驱动第二任务。结果表明：双任务所耗费的心理资源更多, 同时双任务加工过程中第一任务奖励信息编码的半球优势效应与任务的性质有关。     

Brain responses to lexical-semantic priming in children at-risk for dyslexia

Deviances in early event-related potential (ERP) components reflecting auditory and phonological processing are well-documented in children at familial risk for dyslexia. However, little is known about brain responses which index processing in other linguistic domains such as lexicon, semantics and syntax in this group. The present study investigated effects of lexical-semantic priming in 20- and 24-month-olds at-risk for dyslexia and typically developing controls in two ERP experiments. In both experiments an early component assumed to reflect facilitated lexical processing for primed words was enhanced in the at-risk group compared to the control group. Moreover, an N400-like response which was prominent in the control group was attenuated or absent in at-risk children. Results suggest that deficiencies in young children at-risk for dyslexia are not restricted to perceptual and lower-level phonological abilities, but also affect higher order linguistic skills such as lexical and semantic processing.     

海洛因戒断者吸毒及情绪注意偏向的ERP研究

海洛因戒断组对吸毒、正、负性线索注意偏向是理解戒断者复吸脑机制的重要手段之一。研究采用dot-probe实验范式,海洛因戒断组及正常被试各10名,分别记录64个电极点脑电数据。结果表明,戒断者吸毒线索注意偏向P200振幅显著高于正负性情绪线索,也显著高于正常组,提示戒断者存在吸毒线索注意偏向;N300振幅显著低于正常组,说明戒断者具有较低的情绪评价;吸毒线索诱发P300振幅显著高于正常组,表明戒断组对吸毒线索可能附加情绪加工。     

空间-数字反应编码联合效应下冲突适应过程的ERP研究

为了考察被试在不能意识到任务中包含冲突的情况下的认知控制过程,将产生SNARC效应的奇偶判断任务看作是一种潜在的冲突任务。大小与反应手一致的视为一致的试次,大小与反应手不一致的视为不一致的试次。根据不一致试次之前一个试次的类型将其划分为iI(不一致—不一致,incongruent-incongruent)试次和cI(一致—不一致,congruent-incongruent)试次两种类型。对冲突适应过程的分析表明iI试次的反应时显著快于cI试次,iI试次和cI试次相比,两者的脑电在大约260~300ms的时间段内在FCz位置上差异最大。偶极子分析表明差异波的产生源定位于背侧前扣带回(dorsal anterior cingulate cortex),这些结果与前扣带回的意识监测理论并不一致。最后结合冲突监测理论和其他解释前扣带回功能的理论对研究结果做了相应的解释,认为冲突适应可以是一个无意识的过程     

Evaluative priming from subliminal emotional words: Insights from event-related potentials and individual differences related to anxiety

The present ERP study investigated effects of subliminal emotional words on preference judgments about subsequent visual target stimuli (paintings, portraits). Each target was preceded by a masked 17-ms emotional adjective. Four classes of prime words were distinguished according to the combinations of positive/negative valence and high/low arousal. Targets were liked significantly more after positive-arousing primes (e.g., happy), relative to negative-arousing (brutal), positive-nonarousing (mild), and negative-nonarousing primes (lazy). In the target ERP, amplitude of right-hemisphere positive slow wave was increased after positive-arousing compared to negative-arousing primes. Evaluative priming effects on judgments and ERPs were more pronounced in high state-anxious participants. The results suggest that (1) there is indeed affective/semantic processing of unconscious words, (2) evaluative priming operates relatively late during target processing, (3) to be effective, prime words need to score high on the arousal dimension, and (4) individual differences in state anxiety modulate the susceptibility to subliminal evaluative priming.     

Event-related potential correlates of visual identity negative priming unbiased by trial-by-trial effects

Negative priming (NP) refers to slowed reaction times and/or less accurate responses in people responding to a target that was ignored on a previous trial. Although extensive research with behavioral measures has been conducted, little is known about the electrophysiological mechanisms underlying this effect. The few previous studies carried out have led to contradictory results, supporting either episodic-retrieval or inhibition-based theoretical perspectives. In this study, we analyzed the ERP correlates of negative priming by using an experimental global context which, similar to the NP standard context, included Attended repetition trials. In addition, we presented relevant stimuli in separate blocks instead of the more usual randomized design. The NP effect can be biased by strategies adopted by participants when attended and ignored repetition trials are presented randomly. Specifically, we observed an enhanced N2 when a distractor from the previous trial became the target in the next trial. It is supposed that this finding reflects the involvement of additional attentional resources in the selection of a previously inhibited distractor as the new target stimuli.     

ERP and MEG correlates of visual consciousness: The second decade

The first decade of event-related potential (ERP) research had established that the most consistent correlates of the onset of visual consciousness are the early visual awareness negativity (VAN), a posterior negative component in the N2 time range, and the late positivity (LP), an anterior positive component in the P3 time range. Two earlier extensive reviews ten years ago had concluded that VAN is the earliest and most reliable correlate of visual phenomenal consciousness, whereas LP probably reflects later processes associated with reflective/access consciousness. This article provides an update to those earlier reviews. ERP and MEG studies that have appeared since 2010 and directly compared ERPs between aware and unaware conditions are reviewed, and important new developments in the field are discussed. The result corroborates VAN as the earliest and most consistent signature of visual phenomenal consciousness, and casts further doubt on LP as an ERP correlate of phenomenal consciousness.     

Neural underpinnings of the relationships between sensation seeking and emotion regulation in adolescents

There is little neurological evidence linking sensation seeking and emotion regulation in adolescence, which is characterised as an emotionally fluctuant period. The present study examined the relationship between sensation seeking and emotion regulation in adolescents. Electroencephalograms were recorded from 22 high sensation-seeking adolescents (HSSs, M_age = 12.36) and 24 low sensation-seeking adolescents (LSSs, M_age = 12.84) during the reactivity and regulation-image task. Group differences in event-related brain potentials (ERPs) associated with the regulation of negative and neutral stimuli were analysed. The results showed that (a) the P2 of HSSs were larger than LSSs during emotion regulation; (b) in down-regulation conditions, the LPP in all time windows were smaller than no-regulation in LSSs. However, there was no significant difference in HSSs; (c) the LPP 300–600 and LPP 1000–1500 of down-regulation were smaller in LSSs than HSSs; (d) for LPP 600–1000, HSSs induced larger LPP than LSSs in the negative down-regulation and negative no-regulation conditions. The results provide neurological evidence that higher sensation seeking is related to the high reactivity to emotional stimuli and poor cognitive control during the regulation of emotions.     

Psychological refractory period in introverts and extraverts

The present study was designed to explore extraversion-related differences in the psychological refractory period (PRP). PRP refers to a bottleneck of information processing that becomes evident when participants are required to respond to two signals (S1 and S2) presented in rapid succession. If this capacity limit of premotor information processing is essential for differences in speed of information processing between introverts and extraverts, magnitude of the PRP effect should vary as a function of extraversion. Due to the failure of previous attempts to establish extraversion-related differences in the PRP effect, we also obtained lateralized readiness potentials (LRPs). For this purpose, 63 introverted and 63 extraverted female participants were tested with a standard PRP design. Extraverts responded faster to S2 and exhibited shorter stimulus-locked LRP latencies compared to introverts. Although a general PRP effect could be shown at the behavioral and psychophysiological level, there was no indication for any extraversion-related differences in PRP. Thus, extraversion-related differences in speed of information processing at the premotor level appear unlikely to originate from individual differences in the capacity limits underlying the PRP phenomenon. Furthermore, our findings provide converging evidence for the notion that extraversion-related individual differences in processing speed depend on specific task demands.     

Electrophysiological changes during adolescence: A review

While psychological research has long shown that adolescence is a period of major cognitive and affective transition, recent neurophysiological research has shown that adolescence is also accompanied by observable maturational changes in the brain, both in terms of structure and neurotransmitter function. Given this situation, we would expect that there should be observable and perhaps major changes in electrocortical activity and responses. In this review, we discuss developmental reductions in EEG power and alterations in the dominant band of EEG oscillation frequency, moderated by developmental factors such as growth-related changes in grey and white matter, and in the developmental history of cognitive and sociocultural stressors. Similarly, we summarize alterations in event-related potential components reflecting stimulus processing, response monitoring, and response anticipation. We review the literature on such changes in EEG and event-related potentials during the adolescent period and summarize some of the new developments in the field as well as interpretative difficulties.