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)

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)

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)

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 (EST) with the use of an orthogonal factorial manipulation for emotional valence, arousal, and subjective significance (the importance of the current experience for goals and plans for the future). 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)

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)

Although the word-frequency effect is one of the most established findings in spoken-word recognition, the precise processing locus of this effect is still a topic of debate. In this study, we used event-related potentials (ERPs) to track the time course of the word-frequency effect. In addition, the neighborhood density effect, which is known to reflect mechanisms involved in word identification, was also examined. The ERP data showed a clear frequency effect as early as 350 ms from word (...) onset on the P350, followed by a later effect at word offset on the late N400. A neighborhood density effect was also found at an early stage of spoken-word processing on the PMN, and at word offset on the late N400. Overall, our ERP differences for word frequency suggest that frequency affects the core processes of word identification starting from the initial phase of lexical activation and including target word selection. They thus rule out any interpretation of the word frequency effect that is limited to a purely decisional locus after word identification has been completed. (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)

Event-related potential studies have attempted to discover the processes that underlie conscious visual perception by contrasting ERPs produced by stimuli that are consciously perceived with those that are not. Variability of the proposed ERP correlates of consciousness is considerable: the earliest proposed ERP correlate of consciousness coincides with sensory processes and the last one marks postperceptual processes. A negative difference wave called visual awareness negativity , typically observed around 200 ms after stimulus onset in occipitotemporal sites, gains strong (...) support for reflecting the processes that correlate with, and possibly enable, aware visual perception. Research suggests that the early parts of conscious processing can proceed independently of top-down attention, although top-down attention may modulate visual processing even before consciousness. Evidence implies that the contents of consciousness are provided by interactions in the ventral stream, but indispensable contributions from dorsal regions influence already low-level visual responses. (shrink)

Humans are fast and accurate in categorizing complex natural images. It is, however, unclear what features of visual information are exploited by brain to perceive the images with such speed and accuracy. It has been shown that low-level contrast statistics of natural scenes can explain the variance of amplitude of event-related potentials (ERP) in response to rapidly presented images. In this study, we investigated the effect of these statistics on frequency content of ERPs. We recorded ERPs from (...) human subjects, while they viewed natural images each presented for 70 ms. Our results showed that Weibull contrast statistics, as a biologically plausible model, explained the variance of ERPs the best, compared to other image statistics that we assessed. Our time-frequency analysis revealed a significant correlation between these statistics and ERPs’ power within theta frequency band (~3-7 Hz). This is interesting, as theta band is believed to be involved in context updating and semantic encoding. This correlation became significant at ~110 ms after stimulus onset, and peaked at 138 ms. Our results show that not only the amplitude but also the frequency of neural responses can be modulated with low-level contrast statistics of natural images and highlights their potential role in scene perception. (shrink)

The study of instabilities in perception has attracted much interest in recent decades. The presented investigations focus on electrophysiological correlates of orientation reversals of both ambiguous visual stimuli and alternating non-ambiguous stimuli, representing the two options of the ambiguous version. Based on a refined experimental setup, significant features in the event-related potentials associated with the perception of orientation reversal were found in both cases. Their occipital location, their early occurence (200–250 ms), and their latency difference (50 ms) (...) offer interesting perspectives for an understanding of unstable brain states in terms of basic concepts of dynamical systems. (shrink)

Linguistic predictions may be generated from and evaluated against a representation of events and referents described in the discourse. Compatible with this idea, recent work shows that predictions about novel noun phrases include their definiteness. In the current follow-up study, we ask whether people engage similar prediction-related processes for definite and indefinite referents. This question is relevant for linguistic theories that imply a processing difference between definite and indefinite noun phrases, typically because definiteness is thought to require a uniquely (...) identifiable referent in the discourse. We addressed this question in an event-related potential (ERP) study (N = 48) with preregistration of data acquisition, preprocessing, and Bayesian analysis. Participants read Dutch mini-stories with a definite or indefinite novel noun phrase (e.g., “het/een huis,” the/a house), wherein (in)definiteness of the article was either expected or unexpected and the noun was always strongly expected. Unexpected articles elicited enhanced N400s, but unexpectedly indefinite articles also elicited a positive ERP effect at frontal channels compared to expectedly indefinite articles. We tentatively link this effect to an antiuniqueness violation, which may force people to introduce a new referent over and above the already anticipated one. Interestingly, expectedly definite nouns elicited larger N400s than unexpectedly definite nouns (replicating a previous surprising finding) and indefinite nouns. Although the exact nature of these noun effects remains unknown, expectedly definite nouns may have triggered the strongest semantic activation because they alone refer to specific and concrete referents. In sum, results from both the articles and nouns clearly demonstrate that definiteness marking has a rapid effect on processing, counter to recent claims regarding definiteness processing. (shrink)

The aim of the study was to assess the effects of visual aesthetic perception on event-related potentials . Eight subjects assigned an aesthetic judgment and a 10-step beauty estimation to the target stimuli, consisting of famous artistic pictures and geometric shapes. In a further task, the subjects performed a motor response to the previously judged pictures and geometric shapes. ERPs were recorded through 54 scalp electrodes during both tasks. The P3b amplitude was increased during the categorization of (...) the geometric shapes compared to the artistic figures and during the vision of the beautiful targets preceding the motor response. The categorization of the aesthetic qualities of geometrical shapes seems to induce a higher level of attention, while a higher arousal variation was elicited by the recognition of beauty, in any form that was presented. (shrink)

This study examines the event- related brain potential (ERP) of 25 Mexican monolingual Spanish-speakers when reading Spanish sentences with single entity anaphora or complex anaphora. Complex anaphora is an expression that refer to propositions, states, facts or events while, a single entity anaphora is an expression that refers back to a concrete object. Here we compare the cognitive cost in processing a single entity anaphora [éstafeminine; La renuncia (resignation)] from a complex anaphora [estoneuter; La renuncia fue aceptada (The (...) resignation was accepted)].Éstaelicited a larger positive peak at 200 ms, andestoelicited a larger frontal negativity around 400 ms. The positivity resembles the P200 component, and its amplitude is thought to represent an interaction between predictive qualities in sentence processing (i.e., graphical similarity and frequency of occurrence). Unlike parietal negativities (typical N400), frontal negativities are thought to represent the ease by which pronouns are linked with its antecedent, and how easy the information is recovered from short-term memory. Thus, the complex anaphora recruited more cognitive resources than the single entity anaphora. We also included an ungrammatical control sentence [éstemasculine; La renuncia (resignation)] to better understand the unique processes behind complex anaphoric resolution, as opposed to just general difficulty in sentence processing. In this case, event-related potentials (ERPs) elicited byéstemasculineandéstafemininewere compared. Again,éstaelicited a larger P200. However, different from the experimental condition, a left anterior negativity (LAN) effect was observed foréste; the ungrammatical condition. Altogether, the present research provides electrophysiological evidence indicating that demonstrative pronouns with different morphosyntactic features (i.e., gender) and discourse parameters (i.e., single entity or complex referent) interact during the first stage of anaphoric processing of anaphora. This stage initiated as early as 200 milliseconds after the pronoun onset and probably ends around 400 ms. (shrink)

This paper investigated how implicit and explicit knowledge is reflected in event-related potentials in sequence learning. ERPs were recorded during a serial reaction time task. The results showed that there were greater RT benefits for standard compared with deviant stimuli later than early on, indicating sequence learning. After training, more standard triplets were generated under inclusion than exclusion tests and more standard triplets under exclusion than chance level, indicating that participants acquired both explicit and implicit knowledge. However, (...) deviant targets elicited enhanced N2 and P3 components for targets with explicit knowledge but a larger N2 effect for targets with implicit knowledge, revealing that implicit knowledge expresses itself in relatively early components and explicit knowledge in additional P3 components. The results help resolve current debate about the neural substrates supporting implicit and explicit learning. (shrink)

The unwillingness of college students to use recycled water has become a key barrier to sewage recycling on campus, and it is critical to strengthen their inclination to do so. This paper used college students in Xi’an as a case study and adopted event-related potential technology to explore the effect of social norms on the willingness to use recycled water and the neural mechanism of cognitive processing. The results suggested the following: The existence of social norms might influence (...) college students’ willingness to use recycled water. When individuals’ willingness to use recycled water is lower than the social norm, there is a bigger feedback-related negative amplitude. College students pay more attention to social norms in groups with closer social distance. These findings can be used to provide a scientific basis for persuading the public to use recycled water from the perspective of the social norm to drive public acceptability. (shrink)