P3 is the most prominent of the electrical potentials of the human electroencephalogram that are sensitive to psychological variables. According to the most influential current hypothesis about its psychological significance [E. Donchin's], the “context updating” hypothesis, P3 reflects the updating of working memory. This hypothesis cannot account for relevant portions of the available evidence and it entails some basic contradictions. A more general formulation of this hypothesis is that P3 reflects the updating of expectancies. This version implies that P3-evoking stimuli (...) are initially unexpected but later become expected. This contradiction cannot be resolved within this formulation. The alternative “context closure” hypothesis retains the concept of “strategic information processing” emphasized by the context updating hypothesis. P3s are evoked by events that are awaited when subjects deal with repetitive, highly structured tasks; P3s arise from subjects' combining successive stimuli into larger units. The tasks in which P3s are elicited can accordingly be classified in terms of their respective formal sequences of stimuli. P3 may be a physiological indicator of excess activation being released from perceptual control areas. (shrink)

The present study applies a new method for investigating dynamic unconscious processes. The method consists of selection of words from patient interview and test protocols that in the clinicians' judgments capture the patients' conscious symptom experience and the hypothetical unconscious conflict related to the symptom, subliminal and supraliminal presentation of these words, signal analysis of event-related potentials obtained to the word presentations. Eight phobics and three patients suffering from pathological grief reactions served as subjects. A time-frequency ERP (...) analysis revealed that subjects' ERPs classified the unconscious conflict words better subliminally than supraliminally, while the reverse was true for the conscious symptom words = 2.82, p = .011). The relationship between frequency and latency revealed a similar mirror image pattern for the unconscious conflict and conscious symptom words . This method demonstrated that objective, brain-based evidence for unconscious conflict can be obtained. (shrink)

The current work investigated whether differences in phonological overlap between the past- and present-tense forms of regular and irregular verbs can account for the graded neurophysiological effects of verb regularity observed in past-tense priming designs. Event-related potentials were recorded from 16 healthy participants who performed a lexical-decision task in which past-tense primes immediately preceded present-tense targets. To minimize intra-modal phonological priming effects, cross-modal presentation between auditory primes and visual targets was employed, and results were compared to a companion (...) intra-modal auditory study (Justus, T., Larsen, J., de Mornay Davies, P., Swick, D. (2008). Interpreting dissociations between regular and irregular past-tense morphology: evidence from event-related potentials. Cognitive, Affective, Behavioral Neuroscience, 8, 178–194.). For both regular and irregular verbs, faster response times and reduced N400 components were observed for present-tense forms when primed by the corresponding past-tense forms. Although behavioral facilitation was observed with a pseudopast phonological control condition, neither this condition nor an orthographic-phonological control produced significant N400 priming effects. Instead, these two types of priming were associated with a post-lexical anterior negativity (PLAN). Results are discussed with regard to dual- and single-system theories of inflectional morphology, as well as intra- and cross-modal prelexical priming. (shrink)

ERPs (event-related potentials) correlates are largely used in cognitive psychology and specifically for analysis of semantic information processing. Previous research has underlined a strong correlation between a negative-ongoing wave (N400), more frontally distributed, and semantic linguistic or extra-linguistic anomalies. With reference to the extra-linguistic domain, our experiment analyzed ERP variation in a semantic task of comprehension of emotional facial expressions. The experiment explored the effect of expectancy violation when subjects observed congruous or incongruous emotional facial patterns. Four prototypical (...) (anger, sadness, happiness and surprise) and four morphed faces were presented. Moreover, two distinct cognitive tasks (an implicit vs an explicit elaboration) were analyzed in order to evaluate the influence of spontaneous decoding in N400-like effects. An automatic, high-order cognitive process was found, elicited by a negative ERP variation similar to the linguistic N400 effect, which allows us to explain the congruous/incongruous decoding in semantic extra-linguistic comprehension. (shrink)

This study investigated the effect of obstructive sleep apnea on the neural mechanism of visual perception. A preliminary case-control study was conducted. Seventeen patients with moderate to severe OSA in the sleep center of Civil Aviation General Hospital and 20 healthy controls matched for age, sex, and education were recruited. The participants accepted the perceptual contour integration task, compared the differences in behavioral indicators between the two groups, and compared the differences in electroencephalography data between the two groups through (...) class='Hi'>event-related potential technology. The groups did not differ significantly in age and gender, but they differed significantly in body mass index. The groups were not statistically different in terms of sleep structure and total sleep time. AHI, sleep efficiency, and minimal SaO2 value in the OSA group were significantly different from those of the control group. The results showed that the average reaction time of the OSA group was significantly longer than that of the healthy control group in the contour integration task. There was no significant difference in the accuracy rate. The results of EEG showed that the amplitudes of N100 of the OSA group were significantly higher than those of the control group at O1, Oz, and O2 electrodes. There was no significant difference in latency between the two groups. At the FCz electrode, the amplitudes of N200 of the OSA group were significantly higher than those of the control group. Therefore, we concluded that in the early stage of the perceptual integration task, although the neural response activity of patients with moderate and severe OSA was not accelerated, they need to call on more psychological resources, activate more neurons in the contour global recognition processing stage, and the compensatory effect of frontal lobe appeared in the stage of visual perception. (shrink)

This study explored the syntactic transfer effect of the non-local subject-verb agreement structure with plural head noun after two intensive phases of input training with event-related potentials (ERP). The non-local subject-verb agreement stimuli with the plural head nouns, which never appeared in training phases, were used for the stimuli. A total of 26 late L1-Chinese L2-English learners, who began to learn English after a critical period and participated in our previous experiments, were asked back to take part in (...) this syntactic transfer experiment. Results indicated that a significant ERP component P600 occurred in the key region (the verb) of the sentences with syntactic violations in the experimental group, but none occurred in the control group. This demonstrated that there was a significant transfer effect of the input training. The possible theoretical explanation was provided and also the malleability of the late L2 learners was discussed. (shrink)

Easy of learning judgments occur before active learning begins, and it is a prediction of how difficult it will be to learn new material in future learning. This study compared the amplitude of event-related potential components and brain activation regions between high and low EOL judgments by adopting ERPs with a classical EOL judgment paradigm, aiming to confirm the ease-of-processing hypothesis. The results showed that the magnitudes of EOL judgments are affected by encoding fluency cues, and the (...) judgment magnitude increases with encoding fluency; low EOL judgments are associated with higher N400 amplitude at the left superior frontal gyrus and left middle frontal gyrus. High EOL judgments showed enlarged slow-wave potentials than low EOL judgments at the left medial temporal lobe, right ventromedial prefrontal cortex, and dorsolateral prefrontal cortex. Our results support the ease-of-processing hypothesis, particularly, by affirming that EOL judgments are affected by encoding fluency in two processing stages. N400 reflects the process of acquiring encoding fluency cues, while slow-wave indicates that individuals use encoding fluency cues for metacognitive monitoring. (shrink)

The present study is the first to measure event-related potentials associated with the processing of the emotional Stroop task with the use of an orthogonal factorial manipulation for emotional valence, arousal, and subjective significance. The current study aimed to investigate concurrently the role of the three dimensions describing the emotion-laden words for interference control measured in the classical version of the EST paradigm. The results showed that reaction times were affected by the emotional valence of presented words and (...) the interactive effect of valence and arousal. The expected emotional arousal effect was only found in behavioral results for neutrally valenced words. Electrophysiological results showed valence and subjective significance correlated with the amplitude differences in the P2 component. Moreover, the amplitude of the N450 component varied with the level of subjective significance. This study also demonstrated that exploratory event-related potential analysis provides additional information beyond the classical component-based analysis. The obtained results show that cognitive control effects in the EST may be altered by manipulation in the subjective significance dimension. (shrink)

Asking people to discover the identity of a recognition test probe immediately before making a recognition judgment increases the probability of an old judgment. To inform theories of this “revelation effect,” event-related potentials were recorded for revealed and intact test items across two experiments. In Experiment 1, we used a revelation effect paradigm where half of the test probes were presented as anagrams and the other items were presented intact. The pattern of ERP results from this experiment suggested (...) that revealing an item decreases initial familiarity levels and caused the revealed items to elicit similar levels of activity. In Experiment 2, half of the probes were preceded by an addition task . The pattern of ERP effects in this study were distinct from those observed in Experiment 1. More specifically, revealed item ERPs were more negative than intact ERPs at frontal electrodes and more positive at parietal electrodes early in the interval. Later in the epoch, revealed item ERPs were more negative than intact items. These data suggest that related tasks decrease familiarity and alter the signal-to-noise ratio of old and new items, whereas unrelated tasks affect processing in a different way that also results in the revelation effect. The implications for current theories of the revelation effect are discussed. (shrink)

BackgroundPrevious findings indicated that breast cancer patients often have dysfunction in empathy and other cognitive functions during or after chemotherapy. However, the manifestations and possible neuro-electrophysiological mechanisms of pain empathy impairment in breast cancer patients after chemotherapy were still unknown.ObjectiveThe current study aimed to investigate the potential correlations between pain empathy impairment and event-related potentials in breast cancer patients undergoing chemotherapy.MethodsTwenty-two breast cancer patients were evaluated on a neuropsychological test and pain empathy paradigm before and after chemotherapy, (...) containing the Chinese version of the Interpersonal Reactivity Index, while recording ERP data.ResultsThe empathic concern scores were lower and personal distress scores were higher on IRI-C task compared with those before chemotherapy. Meanwhile, the accuracy rates were lower than those before chemotherapy for both pain and laterality tasks on the pain empathy paradigm. However, the response time was no significant differences before and after chemotherapy. Further, the amplitude of the N1 component was significantly increased, and the amplitude of the P2 component was significantly decreased in the subsequent ERP study. A linear mixed effect model was used to analyze the correlation, the average amplitude of N1 and P2 were positively correlated with the accuracy rates in laterality tasks.ConclusionThe results indicated that pain empathy impairment was performed in chemotherapeutic breast cancer patients, which was possibly correlated to the changes of N1 and P2 components in ERP. These findings provide neuro-electrophysiological information about chemo-brain in breast cancer patients. (shrink)

The tendency of customers’ preference to their local brands over the foreign ones is known as the consumer ethnocentrism, and it is one of the important issues in international marketing. This study aims at identifying the behavioral and neural correlates of Consumer Ethnocentrism in the field of brand preference by using Event-Related Potential (ERP). We sampled subjects from two ethnic groups, the Chinese ethnic group and the sub-Sahara black Africans group from the Zhejiang University. The subjects faced (...) two sequential stimuli, S1 followed by S2. The S1 consisted of 40 pictures of 20 Chinese and 20 Africans black peoples wearing traditional clothes, and S2 consisted of 40 fake brand-logos which were divided randomly into two groups of 20 each. The subjects were informed that the people in the S1 purchased and recommended the products with the brand-logos presented in S2, and the subjects were asked to rate their preference degree toward these logos. The brand-logos were called the “in-group recommended logos” if the recommender in S1 were the same race as the subjects, otherwise, the “out-group recommended logos”.The results revealed that the race of the brand-logo recommender highly impacted the Chinese subjects’ preference for the brand-logos. The N200 component elicited by in-group recommended logos were significantly lower than those elicited by out-group recommended logos. Besides, there was evidence that being familiar with foreign cultures reduces consumer ethnocentrism. The African subjects were familiar with Chinese people and adopted Chinese culture, as a result, they did not differ in showing preferences between in-group and out-group recommended logos. (shrink)