Current ERP Study Research Articles

Electrophysiological hallmarks for event relations and event roles in working memory.

The ability to maintain events (i.e., interactions between/among objects) in working memory is crucial for our everyday cognition, yet the format of this representation is poorly understood. The current ERP study was designed to answer two questions: How is maintaining events (e.g., the tiger hit the lion) neurally different from maintaining item coordinations (e.g., the tiger and the lion)? That is, how is the event relation (present in events but not coordinations) represented? And how is the agent, or initiator of the event encoded differently from the patient, or receiver of the event during maintenance? We used a novel picture-sentence match-across-delay approach in which the working memory representation was "pinged" during the delay, replicated across two ERP experiments with Chinese and English materials. We found that maintenance of events elicited a long-lasting late sustained difference in posterior-occipital electrodes relative to non-events. This effect resembled the negative slow wave reported in previous studies of working memory, suggesting that the maintenance of events in working memory may impose a higher cost compared to coordinations. Although we did not observe significant ERP differences associated with pinging the agent vs. the patient during the delay, we did find that the ping appeared to dampen the ongoing sustained difference, suggesting a shift from sustained activity to activity silent mechanisms. These results suggest a new method by which ERPs can be used to elucidate the format of neural representation for events in working memory.

Frame-shifting instead of incongruity is necessary for pun comprehension: evidence from an ERP study on Chinese homophone puns

ABSTRACT Recent psycholinguistic research has made significant progress in understanding the meaning-access process during pun comprehension. However, to date, little research has directly investigated how the two retrieved meanings are integrated into the pun context afterwards. In the current ERP study, we examined this process by comparing homophone puns with two control conditions. Different from previous ERP studies on jokes, we did not observe significantly enhanced N400 amplitudes (300-500 ms) in the pun condition, indicating no apparent detection of incongruity. However, we observed a sustained positivity around the left anterior regions (500-900 ms) and enhanced LPC amplitudes around the central-parietal regions (600-900 ms). These two components could index the sudden access to the second meaning and the additional integration operations to establish a new cognitive model respectively. These findings were compatible with the Space Structure Model, which emphasises the frame-shifting process as a crucial element for understanding verbal humour.

Degree of incrementality is modulated by experimental context – ERP evidence from German quantifier restriction

ABSTRACT The current ERP study investigates the role of non-linguistic context in incremental semantic comprehension. Using picture-sentence verification, we examined the neurophysiological correlates of contextual adaptation effects. We manipulated experiment-inherent frequency and tested whether a relatively high ratio of experimental to filler sentences constrains the contextual restriction of the German quantifier alle (“all”). While previous results indicate that the truth evaluation may be postponed when the experimental setting is completely ambiguous with respect to a potentially following restriction, the current study used a higher ratio of non-restricted vs. restricted sentences than the previous one (4:1 vs. 1:1) and thereby tested whether a low restriction probability increases the likelihood of an immediate truth evaluation. Our results show that experiment-inherent frequency distributions immediately modulate the N400 amplitude, analogous to previous studies on speaker reliability.

Non-Symbolic Numerosity and Symbolic Numbers are not Processed Intuitively in Children: Evidence From an Event-Related Potential Study

The approximate number system (ANS) theory and the ANS mapping account have been the most prominent theories on non-symbolic numerosity processing and symbolic number processing respectively, over the last 20 years. Recently, there is a growing debate about these theories, mainly based on research in adults. However, whether the ANS theory and ANS mapping account explain the processing of non-symbolic numerosity and symbolic number in childhood has received little attention. In the current ERP study, we first examined whether non-symbolic numerosity processing in 9-to-12-year-old children (N = 34) is intuitive, as proposed by the ANS theory. Second, we examined whether symbolic number processing is rooted in non-symbolic numerosity processing, as proposed the ANS mapping account. ERPs were measured during four same-different match-to-sample tasks with non-symbolic numerosities, symbolic numbers, and combinations of both. We found no evidence for intuitive processing of non-symbolic numerosity. Instead, children processed the visual features of non-symbolic stimuli more automatically than the numerosity itself. Moreover, children do not seem to automatically activate non-symbolic numerosity when processing symbolic numbers. These results challenge the ANS theory and ANS mapping account in 9-to-12-year-old children.

Word processing deficits in children with isolated and combined reading and spelling deficits: An ERP-study

Dissociations between reading and spelling deficits are likely to be associated with distinct deficits in orthographic word processing. To specify differences in automatic visual word recognition, the current ERP-study compared children with isolated reading fluency deficits (iRD), isolated spelling deficits (iSD), and combined reading fluency and spelling deficits (cRSD) as well as typically developing (TD) 10-year-olds while performing a variant of the Reicher-Wheeler paradigm: children had to indicate which of two letters occurred at a given position in a previously presented word, legal pseudoword, illegal pseudoword or nonword. Event-related potentials (N200 and N400) associated with sublexical orthographic and lexical orthographic processing as well as phonological word processing were analyzed. All groups showed a word superiority effect, both on the behavioral and the neurophysiological level. Group differences occurred for phonological word processing. TD and iRD groups showed a higher N400 activation for illegal pseudowords than for nonwords, while the two spelling deficit groups showed no activation differences between these two stimuli conditions. The findings suggest that differences in phonological word processing are associated with spelling problems: children with iSD showed reduced sensitivity for phonological word processing, while these deficits were not evident in children with iRD.

Abnormal performance monitoring but intact response inhibition in sensation seeking.

The sensation-seeking trait is a potential endophenotype for various addictive behaviors. Using a nonclinical sample, the current ERP study examined the effects of sensation seeking on performance monitoring and response inhibition. Twenty high sensation seekers and 21 low sensation seekers were selected from a large sample based on their sensation-seeking score and performed a stop-signal task while their EEG was recorded. High relative to low sensation seekers displayed similar response inhibition in terms of performance measure and stop-P3 amplitudes. Compared to low sensation seekers, however, high sensation seekers exhibited a reduced stop-N2 for unsuccessful, but not successful, inhibition. Moreover, an enhanced go-N2 in response to go signals was observed for high versus low sensation seekers, irrespective of whether the go signals were followed by a stop signal or not. Together, our findings suggest that sensation seeking in nonclinical populations is related to individual variability in performance monitoring rather than response inhibition, which provides important implications for the prevention and intervention of addictive behaviors that are driven by trait sensation seeking.

When senses meet functions: an amodal stage in conceptual processing

ABSTRACTResearch has shown that concepts are associated with modality-specific features widely distributed in the brain and that semantic hubs or convergence zones may exist to mediate or integrate distributed representations. Although much neuropsychological and neuroimaging literature has provided support for the existence of hubs/convergence zones from the spatial perspective, opinions differ as to whether the representations in the hubs/convergence zones are modality-specific or amodal. The current ERP study aimed to explore whether there is an amodal stage in conceptual processing from the temporal perspective. Participants were presented with prime-target pairs and were asked to judge whether the prime (a sensory or functional feature) could be an attribute of the target (a noun in a natural or artifactual category). The results revealed that a semantic hub or convergence zone may be reached no later than 350–450 ms in conceptual processing and that the representations in the hub may be amodal.

Temporal and spectral profiles of conflict processing among multiple frames of reference.

Individuals rely on various frames of reference (FORs), such as an egocentric FOR (EFOR) and intrinsic FOR (IFOR), to represent spatial information. Previous behavioral studies have shown different IFOR-IFOR (II) and EFOR-IFOR (EI) conflict effects and an effect of their interaction. However, the neural mechanism of conflict processing between two FOR-based conflicts is unclear. In the current ERP study, two FOR-based conflicts were manipulated using a two-cannon task to elucidate common and distinct brain mechanisms that underlie FOR-based conflict processing. The behavioral results showed that both conflicts exhibited longer reaction times and larger error rates in the II (180° cannon angle) and EI (target cannon pointed down) incongruent conditions than in the II (0° cannon angle) and EI (target cannon pointed up) congruent conditions and that an interaction existed between the two conflicts. The ERP results indicated that, for both conflicts, more negative N2 amplitudes and less positive P3 amplitudes occurred in the incongruent conditions than in the congruent conditions, and the interactions between the two conflicts during later P3 amplitudes were significant. Time-frequency analysis further indicated that, in the early time window, the II conflict and the EI conflict specifically modulated power in the theta bands and beta bands, respectively. In contrast, in the later time window, both conflicts modulated power in the alpha and beta bands. In summary, our findings provide insights into the potential existence of two specific early conflict monitoring systems and a general late executive control system for FOR-based conflicts.

Neurophysiological evidence for diminished monitoring of own, but intact monitoring of other's errors in schizophrenia

Schizophrenia is characterized by social deficits. Correctly monitoring own and others’ performance is crucial for efficient social behavior. Deficits in monitoring own performance as reflected in reduced error-related negativity (rERN) amplitudes, have been demonstrated repeatedly in schizophrenia. A similar ERP component (observed ERN; oERN) is elicited when observing others' mistakes. However, possible deficits in monitoring others' performance have never been investigated in schizophrenia. The current ERP-study compared a group of schizophrenia patients (N=22) and healthy controls (N=21) while performing a Simon task and the social Simon task, enabling the investigation of own (rERN) and others' (oERN) performance monitoring. Patients showed slower reaction times, but comparable accuracy and compatibility effects in both tasks. As expected, patients' rERN amplitudes were reduced. Importantly however, oERN amplitudes were comparable between both groups. While monitoring own performance is compromised in schizophrenia, monitoring others' performance seems intact. This divergence between internal and external performance monitoring in patients is in line with studies showing normal neurophysiological responses to negative feedback. The presently found dissociation may improve our understanding of cognitive and neural mechanisms underlying monitoring of own and others’ performance and may stimulate treatment development aimed at learning from external rather than internal error information in schizophrenia.

Priming with threatening faces modulates the self-face advantage by enhancing the other-face processing rather than suppressing the self-face processing

Social emotional information influences self-processing in everyday activities, but few researchers have investigated this process. The current ERP study adopted a prime paradigm to investigate how socially threatening faces impact on the self-face processing advantage. After being primed with emotional faces (happy, angry or neutral), participants judged whether the target face (self, friend, and stranger) was familiar or unfamiliar. Results showed an interaction effect between the prime face and the target face at posterior P3, suggesting that after priming with happy and neutral faces, self-faces elicited larger P3 amplitudes than friend-faces and stranger-faces; however, after priming with angry faces, the P3 amplitudes were not significantly different between self-face and friend-face. Moreover, the P3 amplitudes of self-faces did not differ between priming with angry and neutral faces; however, the P3 amplitude of both friend-faces and stranger-faces showed enhanced responses after priming with angry faces compared to priming with neutral faces. We suggest that the self-face processing advantage (self vs. friend) could be weakened by priming with threatening faces, through enhancement of the other-faces processing rather than suppression of self-faces processing in angry vs. neutral face prime.

The whole is more than the sum of its parts – Audiovisual processing of phonemes investigated with ERPs

In the current ERP study, an active oddball task was carried out, testing pure tones and auditory, visual and audiovisual syllables. For pure tones, an MMN, an N2b, and a P3 were found, confirming traditional findings. Auditory syllables evoked an N2 and a P3. We found that the amplitude of the P3 depended on the distance between standard and deviant. A smaller distance required more attention, which was reflected in a larger amplitude. An analysis of audiovisual material, after correction for visual activity, showed that McGurk type stimuli evoked brain responses that differed from both the standard and the congruent deviants. Finally, we found that congruent audiovisual stimuli elicited an N2 with a shorter latency and a P3 with a smaller amplitude than auditory stimuli. The current ERP study, thus, shows that for audiovisual processing the whole is more than the sum of its parts.

Exploring modality switching effects in negated sentences: further evidence for grounded representations.

Theories of embodied cognition (e.g., Perceptual Symbol Systems Theory; Barsalou, 1999, 2009) suggest that modality specific simulations underlie the representation of concepts. Supporting evidence comes from modality switch costs: participants are slower to verify a property in one modality (e.g., auditory, BLENDER-loud) after verifying a property in a different modality (e.g., gustatory, CRANBERRIES-tart) compared to the same modality (e.g., LEAVES-rustling, Pecher et al., 2003). Similarly, modality switching costs lead to a modulation of the N400 effect in event-related potentials (ERPs; Collins et al., 2011; Hald et al., 2011). This effect of modality switching has also been shown to interact with the veracity of the sentence (Hald et al., 2011). The current ERP study further explores the role of modality match/mismatch on the processing of veracity as well as negation (sentences containing “not”). Our results indicate a modulation in the ERP based on modality and veracity, plus an interaction. The evidence supports the idea that modality specific simulations occur during language processing, and furthermore suggest that these simulations alter the processing of negation.

The neural time course of art perception: An ERP study on the processing of style versus content in art

A central prerequisite to understand the phenomenon of art in psychological terms is to investigate the nature of the underlying perceptual and cognitive processes. Building on a study by Augustin, Leder, Hutzler, and Carbon (2008) the current ERP study examined the neural time course of two central aspects of representational art, one of which is closely related to object- and scene perception, the other of which is art-specific: content and style. We adapted a paradigm that has repeatedly been employed in psycholinguistics and that allows one to examine the neural time course of two processes in terms of when sufficient information is available to allow successful classification. Twenty-two participants viewed pictures that systematically varied in style and content and conducted a combined go/nogo dual choice task. The dependent variables of interest were the Lateralised Readiness Potential (LRP) and the N200 effect. Analyses of both measures support the notion that in the processing of art style follows content, with style-related information being available at around 224ms or between 40 and 94ms later than content-related information. The paradigm used here offers a promising approach to further explore the time course of art perception, thus helping to unravel the perceptual and cognitive processes that underlie the phenomenon of art and the fascination it exerts.

Pauses and Intonational Phrasing: ERP Studies in 5-month-old German Infants and Adults

In language learning, infants are faced with the challenge of decomposing continuous speech into relevant units, such as syntactic clauses and words. Within the framework of prosodic bootstrapping, behavioral studies suggest infants approach this segmentation problem by relying on prosodic information, especially on acoustically marked intonational phrase boundaries (IPBs). In the current ERP study, we investigate processing of IPBs in 5-month-old infants by varying the acoustic cues signaling the IPB. In an experiment in which pitch variation, vowel lengthening, and pause cues are present (Experiment 1), 5-month-old German infants show an ERP obligatory response. This obligatory response signals lower level perceptual processing of acoustic cues that, however, disappear when no pause cue is present (Experiment 2). This suggests that infants are sensitive to sentence internal pause, a cue that is relevant for the processing of IPBs. Given that German adults show both the obligatory components and the closure positive shift, a particular ERP component known to reflect the perception of IPBs, independent of the presence of a pause cue, the results of the current ERP study indicate clear developmental differences in intonational phrase processing. The comparison of our neurophysiological data from German-learning infants with behavioral data from English-learning infants furthermore suggests cross-linguistic differences in intonational phrase processing during infancy. These findings are discussed in the light of differences between the German and the English intonation systems.

Dissociable pitch processing mechanisms in lexical and melodic contexts revealed by ERPs

The current ERP study examined the neural substrates for pitch processing in music and in tonal language with phrases ending in either congruous or incongruous pitches. In a tonal language, like Chinese, pitch is lexically relevant as it can change the meaning of words, and it could therefore be hypothesized that pitch information under this condition is processed differently from musical pitch. Female Chinese musicians were chosen as listeners for their ample exposure to music and a tonal language. Pitch violations in both domains were associated with a frontally distributed late positive component (LPC). In addition to evoking an N400 for language condition, pitch processing as revealed by the LPCs is left lateralized for tonal language and right lateralized for music. We propose that our data may imply different brain resources engaging in pitch processing depending on whether its function is lexical, as in a tonal language like Chinese, or musical in nature.