Event-related Potential Results Research Articles

The Roles of Segments and Tone in Mandarin Lexical Processing: An ERP Study.

Segments and tone are important sub-syllabic units that play large roles in lexical processing in tonal languages. However, their roles in lexical processing remain unclear, and the event-related potential (ERP) technique will benefit the exploration of the cognitive mechanism in lexical processing. The high temporal resolution of ERP enables the technique to interpret rapidly changing spoken language performances. The present ERP study examined the different roles of segments and tone in Mandarin Chinese lexical processing. An auditory priming experiment was designed that included five types of priming stimuli: consonant mismatch, vowel mismatch, tone mismatch, unrelated mismatch, and identity. Participants were asked to judge whether the target of the prime-target pair was a real Mandarin disyllabic word or not. Behavioral results including reaction time and response accuracy and ERP results were collected. Results were different from those of previous studies that showed the dominant role of consonants in lexical access in mainly non-tonal languages like English. Our results showed that consonants and vowels play comparable roles, whereas tone plays a less important role than do consonants and vowels in lexical processing in Mandarin. These results have implications for understanding the brain mechanisms in lexical processing of tonal languages.

Attentional resource consumption of verbal-humor processing: An ERP study

As a high-demanding mental activity with both cognitive and emotional factors, verbal-humor processing consumes more attentional resources than non-humor processing, which has been demonstrated by behavioral studies, but little has been examined at a real-time scale. Based on the three-stage model (incongruity detection, incongruity resolution, and mirth), the current study used event-related potential (ERP) and event-related oscillation (ERO) to explore the attentional resource consumption of verbal-humor processing by employing a dual-task paradigm in which sentence comprehension (humorous, positive, neutral) was the primary task and arithmetical calculation (simple, difficult) was the secondary task.Participants’ (N=38) behavioral performance and ERP/ERO measures in two tasks were analyzed. ERP results of verbal-humor processing revealed significantly larger LAN, LLAN, and LPP activation, which indexed three stages. ERO results showed significant beta power changes in the detection stage and theta changes in the resolution and mirth stages. The behavioral data indicated that the Reaction Times (RTs) of the arithmetical task following verbal-humor processing were longer than those following non-humorous positive and neutral ones. The ERP results of arithmetical calculation found that the calculations following verbal-humor processing elicited significantly greater P2, P3b, and positive slow wave amplitudes than those following the other two processings, which reflected more resource allocation in the calculation to compensate for the resource preemption of verbal-humor processing. In addition, the calculation following positive sentence exhibited a greater ERP amplitude in the relatively early P2 time intervals than that following the neutral sentences. Collectively, the behavioral, ERP, and ERO results concurrently confirmed that verbal-humor processing consumed more attentional resources compared with non-humorous counterparts, and moreover, the comparison of ERP following humorous and positive sentences suggested that the processing of the cognitive factor consumes more attentional resources than the emotional factor although both factors play a role in the process.

Developments of possible clinical diagnostic methods for parkinson’s disease: event-related potentials

ABSTRACT In this study, Event-Related Potential (ERP) analyzes were performed to detect cognitive impairments in PD with Deep Brain Stimulation (DBS). A total of 85 volunteers underwent ERP analysis and neuropsychological testing (NPT) to determine cognitive level. In ERP analyses, prolonged latencies were observed in PD groups. However, patients implanted with DBS showed a decrease in latencies, a decrease in symptoms and statistical improvements in both cognitive and attention skills. Considering all these data, ERP results are promising as a noninvasive method that can be used in both disease status and diagnosis of PD.

Choice overload interferes with early processing and necessitates late compensation: Evidence from electroencephalogram.

Having a multitude of choices can be advantageous, yet an abundance of options can be detrimental to the decision-making process. Based on existing research, the present study combined electroencephalogram and self-reported methodologies to investigate the neural mechanisms underlying the phenomenon of choice overload. Behavioural data suggested that an increase in the number of options led to negative evaluations and avoidance of choice tendencies, even in the absence of time pressure. Event-related potential results indicated that the large choice set interfered with the early visual process, as evidenced by the small P1 amplitude, and failed to attract more attentional resources in the early stage, as evidenced by the small amplitude of P2 and N2. However, the LPC amplitude was increased in the late stage, suggesting greater investment of attentional resources and higher emotional arousal. Multivariate pattern analysis revealed that the difference between small and large choice set began at around 120 ms, and the early and late stages were characterised by opposite activation patterns. This suggested that too many options interfered with early processing and necessitate continued processing at a later stage. In summary, both behavioural and event-related potential (ERP) results confirm the choice overload effect, and it was observed that individuals tend to subjectively exaggerate the choice overload effect.

Does artistic training affect color perception? A study of ERPs and EROs in experiencing colors of different brightness

Color is a visual cue that can convey emotions and attract attention, and there is no doubt that brightness is an important element of color differentiation. To examine the impact of art training on color perception, 44 participants were assigned to two groups—one for those with and one for those without art training—in an EEG experiment. While the participants had their electroencephalographic data recorded, they scored their emotional responses to color stimuli of different brightness levels based on the Munsell color system. The behavioral results revealed that in both groups, high-brightness colors were rated more positively than low-brightness colors. Furthermore, event-related potential results for the artist group showed that high-brightness colors enhanced P2 and P3 amplitudes. Moreover, non-artists had longer N2 latency than artists, and there was a significant Group × Brightness interaction separately for the N2 and P3 components. Simple effect analysis showed that N2 and P3 amplitudes were substantially higher for high-brightness stimuli than for lower-brightness stimuli in the artistic group, but this was not the case in the non-artist group. Additionally, evoked event-related oscillation results showed that in both groups, high-brightness stimuli also elicited large delta, theta, and alpha as well as low gamma responses. These results indicate that high-brightness color stimuli elicit more positive emotions and stronger neurological reactions and that artistic training may have a positive effect on top-down visual perception.

Alexithymia modulates emotion concept activation during facial expression processing.

Alexithymia is characterized by difficulties in emotional information processing. However, the underlying reasons for emotional processing deficits in alexithymia are not fully understood. The present study aimed to investigate the mechanism underlying emotional deficits in alexithymia. Using the Toronto Alexithymia Scale-20, we recruited college students with high alexithymia (n = 24) or low alexithymia (n = 24) in this study. Participants judged the emotional consistency of facial expressions and contextual sentences while recording their event-related potentials. Behaviorally, the high alexithymia group showed longer response times versus the low alexithymia group in processing facial expressions. The event-related potential results showed that the high alexithymia group had more negative-going N400 amplitudes compared with the low alexithymia group in the incongruent condition. More negative N400 amplitudes are also associated with slower responses to facial expressions. Furthermore, machine learning analyses based on N400 amplitudes could distinguish the high alexithymia group from the low alexithymia group in the incongruent condition. Overall, these findings suggest worse facial emotion perception for the high alexithymia group, potentially due to difficulty in spontaneously activating emotion concepts. Our findings have important implications for the affective science and clinical intervention of alexithymia-related affective disorders.

Beneficial effects of communicating intentions when delivering moral criticism: Cognitive and neural responses

People often do not accept criticism on their morality, especially when delivered by outgroup members. In two preregistered studies, we investigated whether people become more receptive to such negative feedback when feedback senders communicate their intention to help. Participants received negative feedback from ostensible others on their selfish (rather than altruistic) decisions in a donation task. We manipulated the identity of a feedback sender (ingroup vs. outgroup) and the intention that they provided for giving feedback. A sender either did not communicate any intentions, indicated the intention to help the feedback receiver improve, or communicated the intention to show moral superiority. We measured participants’ self-reported responses to the feedback (Study 1, N = 44) and additionally recorded an EEG in Study 2 (N = 34). Results showed that when no intentions were communicated, participants assumed worse intentions from outgroup senders than ingroup senders (Study 1). However, group membership had no significant effect once feedback senders made their intentions explicit. Moreover, across studies, when feedback senders communicated their intention to help, participants perceived feedback as less unfair compared with when senders tried to convey their moral superiority. Complementing these results, exploratory event-related potential results of Study 2 suggested that communicating the intention to help reduced participants’ attentional vigilance toward negative feedback messages on their morality (i.e., decreased P200 amplitudes). These results demonstrate the beneficial effects of communicating the intention to help when one tries to encourage others’ moral growth through criticism.

Cognition-Emotion Interaction during L2 Sentence Comprehension: The Correlation of ERP and GSR Responses to Sense Combinations.

This study mainly examined the role of the combination of three senses (i.e., auditory, visual, and tactile) and five senses (i.e., auditory, visual, tactile, olfactory, and gustatory) in the correlation between electrophysiological and electrodermal responses underlying second language (L2) sentence comprehension. Forty subjects did two acceptability judgment tasks, encompassing congruent and semantically/pragmatically incongruent sentences. The event-related potential (ERP) and galvanic skin response (GSR) data for both the target and final words of the sentences were collected and analyzed. The results revealed that there is an interaction between cognitive and emotional responses in both semantically and pragmatically incongruent sentences, yet the timing of the interaction is longer in sentences with pragmatic incongruity due to their complexity. Based on the ERP and GSR correlation results, it was further found that the five-sense combination approach improves L2 sentence comprehension and interest in learning materials yet reduces the level of excitement or arousal. While this approach might be beneficial for some learners, it might be detrimental for those in favor of stimulating learning environments.

The excessive generalization of fear affected by perceptual bias in experimental pain individuals: Evidence from an event-related potential study.

Excessiv generalization of fear contributes to the development and maintenance of pain. Prior research has demonstrated the importance of perception in fear generalization and found that individuals in painful conditions exhibited perceptual bias. However, the extent to which perceptual bias in pain affects the generalization of pain-related fear and its underlying neural activity remains unclear. Here, we tested whether perceptual bias in experimental pain individuals led to the overgeneralization of pain-related fear by recording behavioral and neural responses. To this end, we established an experimental pain model by spraying capsaicin on the surface of the seventh cervical vertebra of the participant. A total of 23 experimental pain participants and 23 matched nonpain controls learned fear conditioning and then completed the fear generalization paradigm combined with the perceptual categorization task. We found that the novel and safety cues were more likely to be identified as threat cues in the experimental group, resulting in higher US expectancy ratings compared to the control group. The event-related potential results showed that the experimental group exhibited earlier N1 latency and smaller P1 and late positive potential amplitudes than those in the control group. Our findings suggest that the experimental pain individuals exhibited an excessive generalization of fear affected by perceptual bias and reduced their attentional allocation to pain-related fear stimuli.

Active inhibition of the retro-cue effect in visual working memory: Evidence from event-related potential.

This study used the event-related potential (ERP) technique to investigate whether active inhibition exists in retro-cue Effect (RCE) in visual working memory using modified retro-cue tasks. In this modified task, the participants were first asked to memorize six color blocks and then presented with directed remembering or directed forgetting cues; finally, their working memory performance was tested. For behavioral results, due to the extension of the memory interval, this study did not find RCE in accuracy but reflected it in the total reaction time. For ERP results, the frontal late positive potential (LPP) followed by the directed forgetting condition was larger than that followed by directed remembering and baseline conditions, and there was no significant difference between directed remembering and baseline conditions. There was no significant difference in parietal P3 followed by both the directed remembering and directed forgetting conditions, which were significantly larger than the baseline condition. This result reveals that active inhibition plays an important role in directed forgetting RCE. There was a correlation between parietal P3 and frontal LPP with the same time window but different scalp regions in the directed forgetting condition, indicating a potential relationship between active inhibition and retelling in directed forgetting RCE.

Sex Differences in Cognitive-Motor Dual-Task Training Effects and in Brain Processing of Semi-Elite Basketball Players.

In the current study, we aimed at evaluating the possible sex differences in cognitive-motor dual-task training (CMDT) effects on the sport and cognitive performance of semi-elite basketball athletes. Moreover, we investigated the CMDT effects on proactive brain processing using event-related potential (ERP) analysis. Fifty-two young basketball athletes (age 16.3 years) were randomly assigned into an experimental (Exp) group performing the CMDT, and a control (Con) group executing standard motor training. Before and after a 5-week training intervention, participants' motor performance was evaluated using dribbling tests. Cognitive performance was assessed by measuring response time and accuracy in a discrimination response task (DRT). Brain activity related to motor and cognitive preparation was measured through the Bereitschaftspotential (BP) and the prefrontal negativity (pN) ERP components. The CMDT involved the simultaneous execution of dribbling exercises and cognitive tasks which were realized using interactive technologies on the court. Results showed that both groups had some enhancements from pre- to post-tests, but only the Exp group enhanced in the dribbling exercise. In the DRT after the CMDT, females performed faster than males in the Exp group. All groups, except for the Con group of males, performed the DRT more accurately after the training. According to the ERP results, in the Exp group of males and in Exp and Con group of females, we found an increase in pN amplitude (associated with better accuracy); in the Exp group of females and in Exp and Con group of males, we found an increase in BP (associated with better response time). In conclusion, the present study endorsed the efficacy of the proposed CMDT protocol on both the sport and cognitive performance of semi-elite basketball players and showed that the neural basis of these benefits may be interpreted as sex-related compensatory effects.

Event-related potential patterns of selective attention modulated by perceptual load.

A high perceptual load can effectively prevent attention from being drawn to irrelevant stimuli; however, the neural pattern underlying this process remains unclear. This study adopted a perceptual load paradigm to examine the temporal processes of attentional modulation by incorporating conditions of perceptual load, distractor-target compatibility, and eccentricity. The behavioral results showed that a high perceptual load significantly reduced attentional distraction caused by peripheral distractors. The event-related potential results further revealed that shorter P2 latencies were observed for peripheral distractors than for central distractors under a high perceptual load and that a suppressed compatibility effect with increasing load was reflected by the P3 component. These findings suggested that (1) P2 and P3 components effectively captured different sides of attentional processing modulated by load (i.e., the filter processing of the object and the overall attentional resource allocation) and (2) response patterns of selective attention modulated by perceptual load were influenced by eccentricity. Our electrophysiological evidence confirmed the behavioral findings, indicating the neural mechanisms of attentional modulation.

The influence of job burnout on the attention ability of army soldiers and officers: Evidence from ERP.

Job burnout is one of the most widespread mental problems in today's society and seriously affects the mental health and combat effectiveness of soldiers and officers. Herein, the effect of burnout on individual attention is studied from the perspective of neuroelectrophysiology. A total of 1,155 army soldiers and officers were included in this investigation and completed the Job Burnout Scale for Military Personnel. A total of 42 soldiers and officers were randomly selected from those with and without burnout to participate in an event-related potential (ERP) study using a visual oddball task. The characteristics of visual P3a and P3b at Fz, FCz, Cz, CPz, and Pz were recorded and analyzed by repeated-measures analysis of variance (ANOVA). P < 0.05 was the criterion for a significant difference. The total average score on the Job Burnout Scale for Military Personnel among the participants was 0.74 ± 0.46, and the detection rate of job burnout was 29.85%. In the Oddball task, the average number of target stimuli counted in the burnout group was lower than that in the control group, but no significant difference was found. For P3a, the Fz, FCz, Cz, CPz, and Pz amplitudes in the burnout group were significantly lower than those in the control group. The average amplitude of P3a evoked in the central parietal area was larger than that in the prefrontal area. For P3b, the amplitudes of the five electrodes in the burnout group were significantly lower than those in the control group. The average amplitude of P3b evoked in the parietal region was larger than those in the prefrontal and central parietal regions. A certain degree of job burnout is evident in army soldiers and officers. The voluntary attention and involuntary attention of individuals with burnout are both affected to some extent, as reflected by the lower amplitudes of P3a and P3b. The results suggest that P3a and P3b can be used as indicators to monitor cognitive neural function in soldiers and officers with burnout and can also be used as references for evaluating the effects of cognitive training and screening methods. In this study, ERP was used to research the attention ability of soldiers and officers with job burnout, and related issues were discussed from the aspects of the burnout results, behavioral results, ERP results, compensation effect of cognitive resources, application in the military field, limitations, and prospects.

Perceived gaze direction affects recollection processes in recognition of concrete and abstract words: electrophysiological evidence.

Studies have revealed that memory performance can be affected by perceived gaze direction. However, it remains unclear whether direct gaze promotes or hinders word memory, and the effect of gaze direction on memory of words with different concreteness requires investigation. In the study phase, concrete and abstract words were presented on direct- or averted-gaze faces, and participants were instructed to judge gaze direction and memorize words. In the test phase, participants were asked to discriminate whether a word was old or new. Electroencephalogram recordings were taken in both phases. Behavioral and time-frequency results verified the direct-gaze memory advantage, showing that memory performance was better in the direct-gaze condition than the averted-gaze condition for both concrete and abstract words. Event-related potential results showed that in both direct- and averted-gaze conditions, the early old/new effects (FN400) associated with familiarity were only elicited for concrete words but not abstract words. The late old/new effects (LPC) associated with recollection were elicited in all conditions. More importantly, concrete words elicited greater LPC than abstract words in the direct-gaze condition, whereas there was no such significant LPC difference in the averted-gaze condition. Topographic map analysis found that neural generators between concrete and abstract words differed in the direct-gaze condition but not in the averted-gaze condition. The study supports the hypothesis that direct-gaze promotes memory performance. Furthermore, it is mainly in memory recollection that gaze direction affects words with different concreteness.

Green Product Types Modulate Green Consumption in the Gain and Loss Framings: An Event-Related Potential Study.

People show a separation of intention and behavior in green consumption, and promoting actual green purchase behavior is more important than purchase intention. This study adopted a conflicting environmental decision paradigm to investigate behavioral and neural processes during actual green consumption decision-making involving different types of green products and message framing, according to construal level theory. Participants were instructed to make green consumption decisions involving green products with different psychological distances (self-interested green products vs. other-interested green products) under gain (e.g., buying green products brings positive results) or loss framing (e.g., not buying green products brings negative effects) while electroencephalograms were recorded. The behavioral results demonstrated that participants tended to purchase green products under loss framing more than under gain framing. The event-related potential results showed that under gain framing, decision-making for self-interested green products was associated with larger P3 than decision-making for other-interested green products. While under loss framing, decision-making for other-interested green products has a larger P260 than for self-interested green products. These findings suggest that under gain framing, self-interested green products elicit more cognitive resources than other-interested green products, while under loss framing, other-interested green products elicit stronger negative emotions than self-interested green products. The research has managerial implications for promoting consumers’ actual purchase behavior.

Decoding the Specificity of Post-Error Adjustments Using EEG-Based Multivariate Pattern Analysis.

Errors can elicit post-error adjustments that serve to optimize performance by preventing further errors. An essential but unsolved issue is that whether post-error adjustments are domain-general or domain-specific, which was investigated in the present study through eliciting different types of errors. Behavioral and electrophysiological data were recorded when male and female subjects performed the Eriksen flanker task. For this study, we examined the aforementioned issue by combining event-related potential and multivariate pattern analysis. The results indicated that post-error slowing, error-related negativity, and error positivity were comparable between congruent and incongruent errors, indicating that errors triggered domain-general interference mechanisms, whereas post-error accuracy and late positive potential elicited by incongruent errors were larger than those elicited by congruent errors, exhibiting domain-specific control adjustment mechanisms. Importantly, no successful decoding soon after errors was found between congruent and incongruent errors, but above-chance decoding was observed between these two types of errors with increasing time, which further support that domain-general adjustments occurred in the early stage, whereas domain-specific adjustments appeared in the late stage. Furthermore, brain-behavior correlation results suggested that the late post-error adjustments predicted subsequent behavior performance. Together, this study revealed that early domain-general interference adjustments induced by errors are reflected in error detection and error awareness, which are independent of error types; on the contrary, late domain-specific control adjustments are reflected in attentional adjustments, which are modulated by error types.SIGNIFICANCE STATEMENT To date, clear evidence on the specificity of post-error adjustments is lacking. The present study provides neurophysiological evidence that post-error adjustments simultaneously rely on both domain-general and domain-specific mechanisms. Event-related potential results indicated that domain-general adjustments were accompanied by the interference of error detection and error awareness. In contrast, domain-specific adjustments were associated with attentional adjustments. Multivariate pattern analysis further decoded the two features of post-error adjustments in the early stage matching the time patterns of error-related negativity and error positivity and in the late stage corresponding to the late positive potential. Temporal generalization analysis showed that domain-specific processing appeared stably in late post-error adjustments. Hence, we propose that post-error different stages may determine the specificity of post-error adjustments.

Bring a map when exploring the ERP data processing multiverse: A commentary on Clayson et al. 2021

Clayson et al. (2021) describe an innovative multiverse analysis to evaluate effects of data processing choices on event-related potential (ERP) measures. Based on their results, they provide data processing recommendations for studies measuring the error-related negativity and error positivity components. We argue that, although their data-driven approach is useful for identifying how data processing choices influence ERP results, it is not sufficient for devising optimal data processing pipelines. As an example, we focus on the inappropriate use of pre-response ERP baselines in their analyses, which leads to biased error positivity amplitude measures. Results of multiverse analyses should be supplemented with further investigation into why differences in ERP results occur across data processing choices before devising general recommendations.

Electrophysiological correlates of the effect of set size on object switching in working memory.

Previous studies have revealed the effect of set size (the number of activated items) on object switching in working memory, but the underlying neural mechanism remains unclear. In this study, participants were asked to first remember two (small size) or three (large size) two-digit numbers and the corresponding geometrical figures as different references for numerical comparison and then compare a series of numbers (10-99) to the reference numbers cued by different geometrical figures. The cue repeated or switched across trials. Behavioral results revealed that the switch cost was greater in the large-size condition than in the small-size condition. Event-related potential results showed that in the N2 component, an interaction was observed between set size and transition, with a significant transition effect (switch minus repeat) in the large-size condition and a non-significant transition effect in the small-size condition. The same interaction was observed in the P3 component, with a larger amplitude difference (switch minus repeat) in the large-size condition than in the small-size condition. These results suggested that when set size is increased, the effort to inhibit the irrelevant items increases, resulting in large cost of object switching in working memory.

Influence of reputational concern and social distance on moral decision-making under the harmful dilemma: Evidence from behavioral and ERPs study

<p id="p00005">Reputational concern has been suggested as an important determinant of human cooperative behavior and moral judgment in social interactions. Previous studies have demonstrated that reputational concern influences behavioral and neural responses during prosocial behaviors and decision-making, such as moral decision-making. Moral decision- making is a typical social decision-making process involving trade-offs between the self and others. It refers to the process in which individuals make optimal choices under the guidance of social systems and norms according to their own value orientations when faced with a variety of possible dilemmas and conflicts in behavioral choices. Emerging studies have shown that social distance modulates behavioral and neural responses during moral decision-making. However, little is known about how reputational concern and social distance interact to affect moral decision-making, particularly regarding the underlying cognitive neural mechanism of moral decision-making associated with proscriptive morality (i.e., harmful behavior). <break/>In the present study, we adopted the “shock-benefit dilemma” task and event-related potential (ERP) technology to examine temporal processing of the interactive influence of reputational concern and social distance on moral decision-making when faced with harmful dilemmas. Participants were instructed to complete a series of alternative dilemmas in an anonymous or public context. After being instructed whether their decisions were going to be made public to the target person, participants decided whether to deliver a certain intensity of painful electric shocks toward the targets (i.e., friends, acquaintances, or strangers) to receive money. A choice not to shock the targets meant that they would forego the benefit. Behavioral and neural responses were recorded while the participants made their decisions. The experiment consisted of 360 trials, including two blocks of anonymous and public situations and 120 trials with friends, acquaintances, and strangers. <break/>The results showed that participants administered fewer electric shocks to friends than to acquaintances and strangers, which suggested an obvious “egoistic altruism” decision tendency in anonymous situations. Participants spent more time and experienced greater disgust in dilemmas involving acquaintances relative to those involving friends and strangers, which showed an obvious “acquaintance effect”. However, these differences were weakened in public situations. As for the ERP results, the dilemmas involving acquaintances elicited a larger P260 component, which is associated with emotional responses, and late positive potential (LPP, 300~450 ms), which is associated with cognitive reasoning. However, these differences in ERP indices disappeared in public situations. <break/>The aim of this study was to explore the interaction between reputational concern and social distance in behavioral and neural responses during moral decision-making involving harmful dilemmas. The results supported the hypothesis that individuals follow the egoistic altruism moral principle to conduct moral decision-making involving reputational concern and social distance. These findings suggest that the uncertainty of acquaintance relations induces stronger negative emotions and cognitive load during moral decision-making, and reputational concern effectively weakens the aversion and dilemma conflict brought about by self-interest tendencies and interpersonal uncertainties.

Relational integration predicted numerical inductive reasoning: ERP Evidence from the N400 and LNC.

As relational integration performance can be used to predict reasoning ability, the present study aimed to provide electrophysiological evidence for numerical inductive reasoning. Number series with two levels of relational complexity were utilized, including simple and hierarchical problems (such as "15-16-17" versus "15-16-18"). Two tasks were adopted: a relational integration task that required to determine whether the numerical relations were changed across numbers; a number series task that required to determine whether a hidden rule was acquired (Experiment 1) or to predict the subsequent number (Experiment 2), whose phases were divided as rule searching, rule discovery, and rule following. The event-related potential (ERP) results of both experiments indicated that, in contrast to simple problems, hierarchical problems triggered enhanced N400 and late negative component (LNC), reflecting numerical fact retrieval, and generalizing novel hypotheses about the hidden rules by integrating adjacent numerical relations, respectively; relational integration showed similar N400 and LNC activation patterns to rule discovery (Experiment 1) or rule searching (Experiment 2). Additionally, the N400 and LNC elicited by relational integration showed strong positive correlations and even were able to predict the ones triggered by rule discovery (Experiment 1) or rule searching (Experiment 2). Therefore, the results supported the role of relational integration in numerical inductive reasoning and thereby in intelligence.