Positive Slow Wave Research Articles

Neuroelectric Evidence for Cognitive Association Formation: An Event-Related Potential Investigation

Although many types of learning require associations to be formed, little is known about the brain mechanisms engaged in association formation. In the present study, we measured event-related potentials (ERPs) while participants studied pairs of semantically related words, with each word of a pair presented sequentially. To narrow in on the associative component of the signal, the ERP difference between the first and second words of a pair (Word2-Word1) was derived separately for subsequently recalled and subsequently not-recalled pairs. When the resulting difference waveforms were contrasted, a parietal positivity was observed for subsequently recalled pairs around 460 ms after the word presentation onset, followed by a positive slow wave that lasted until around 845 ms. Together these results suggest that associations formed between semantically related words are correlated with a specific neural signature that is reflected in scalp recordings over the parietal region.

RETRACTED: Simple mental arithmetic is not so simple: An ERP study of the split and odd–even effects in mental arithmetic

This study aimed to investigate the effects of split size (small vs. large splits) and odd-even congruency (parity congruency vs. parity incongruency) of answers on arithmetical equation processing. Event-related potentials were recorded from 18 students in a first-answer-then-equation presentation mode. The ERP results showed that the odd-even congruency had a significant effect on the late positive wave in the small, but not the large split, with a late positive slow wave elicited by the small-split and the odd-even congruent conditions. This result suggests that the split effect has priority over parity congruency when both split and parity are at play simultaneously. Specifically, in non-retrieval arithmetic verification tasks, parity is modulated in cases where a direct judgment cannot be reached simply by depending on the split information.

Effects of eye gaze cues provided by the caregiver compared to a stranger on infants’ object processing

Previous research has shown that eye gaze affects infants’ processing of novel objects. In the current study we address the question whether presenting a highly familiar face vs. a stranger enhances the effects of gaze cues on object processing in 4-month-olds. Infants were presented pictures of the infant's caregiver and another infant's caregiver (stranger) either turning eye gaze toward an object next to the face or looking away from the object. Then objects were presented again without the face and event-related potentials (ERP) were recorded. An enhanced positive slow wave (PSW) was found for objects that were not cued by the caregiver's eye gaze, indicating that these objects required increased encoding compared to objects that were cued by the caregiver's gaze. When a stranger was presented, a PSW was observed in response to objects regardless of whether the objects were gaze-cued or not. Thus, the caregiver's eye gaze had a larger effect on infants’ object processing than the stranger's gaze. This suggests that at 4 months of age the caregiver's eye gaze is easier to process for infants, more salient, or both. The findings are discussed in terms of early social cognitive development and face processing models.

Assessing the way people look to judge their intentions.

Faces of unknown persons are processed to infer the intentions of these persons not only when they depict full-blown emotions, but also at rest, or when these faces do not signal any strong feelings. We explored the brain processes involved in these inferences to test whether they are similar to those found when judging full-blown emotions. We recorded the event-related brain potentials (ERPs) elicited by faces of unknown persons who, when they were photographed, were not asked to adopt any particular expression. During the ERP recording, participants had to decide whether each face appeared to be that of a positively, negatively, ambiguously, or neutrally intentioned person. The early posterior negativity, the EPN, was found smaller for neutrally categorized faces than for the other faces, suggesting that the automatic processes it indexes are similar to those evoked by full-blown expressions and thus that these processes might be involved in the decoding of intentions. In contrast, in the same 200-400 ms time window, ERPs were not more negative at anterior sites for neutrally intentioned faces. Second, the peaks of the late positive potentials (LPPs) maximal at parietal sites around 700 ms postonset were not significantly smaller for neutrally intentioned faces. Third, the slow positive waves that followed the LPP were larger for faces that took more time to categorize, that is, for ambiguously intentioned faces. These three series of unexpected results may indicate processes similar to those triggered by full-blown emotions studies, but they question the characteristics of these processes.

Brain activity elicited by positive and negative feedback in preschool-aged children.

To investigate the processing of positive vs. negative feedback in children aged 4–5 years, we devised a prize-guessing game that is analogous to gambling tasks used to measure feedback-related brain responses in adult studies. Unlike adult studies, the feedback-related negativity (FRN) elicited by positive feedback was as large as that elicited by negative feedback, suggesting that the neural system underlying the FRN may not process feedback valence in early childhood. In addition, positive feedback, compared with negative feedback, evoked a larger P1 over the occipital scalp area and a larger positive slow wave (PSW) over the right central-parietal scalp area. We believe that the PSW is related to emotional arousal and the intensive focus on positive feedback that is present in the preschool and early school years has adaptive significance for both cognitive and emotional development during this period.

Affective facial expression processing in young children who have experienced maltreatment during the first year of life: An event-related potential study

This study employed event-related potentials (ERPs) to investigate the neural correlates of facial affect processing in maltreated and nonmaltreated children at 42 months of age. ERPs elicited while children passively viewed standardized pictures of female models posing angry, happy, and neutral facial expressions were examined, and differences between maltreated (N = 46) and nonmaltreated (N = 25) children were reported. Three occipital components (P1, N170, and P400) and four frontal-central components (N150, P240, Nc, and a positive slow wave [PSW]) were identified. Findings revealed that maltreated children had greater P1 and P400 amplitude in response to angry facial affect compared to other emotions, and compared to nonmaltreated children. N170 amplitude was greater in response to happy compared to angry in the maltreated group. For the P240 component, maltreated children had greater amplitude in response to angry facial expressions relative to happy, whereas children in the nonmaltreated group had greater P240 amplitude in response to happy relative to angry facial affect. Further, the nonmaltreated group had greater PSW amplitude in response to angry facial affect, whereas those in the maltreated group showed greater PSW amplitude to happy facial expressions. The results provided further support for the hypothesis that the experience of maltreatment and the predominantly negative emotional tone in maltreating families alters the functioning of neural systems associated with the identification and processing of facial emotion. These results exemplify the importance of early preventive interventions focused on emotion for children who have experienced maltreatment early in life.

Individual differences in arithmetic skill reflected in event-related brain potentials

We used event-related brain potentials (ERP) to study the problem-size effect in individuals with high and low arithmetic skill. Participants were presented with a classic equality verification task, and problem size was manipulated by using small (e.g., 3 + 4), medium (e.g., 7 + 8) and large problems (e.g., 16 + 29). ERP analyses were time-locked to the onset of the second operand in order to address brain potentials during the production phase. High-skill individuals showed a positive slow wave when solving large problems and no differences in the ERP pattern when solving small and medium problems. In contrast, low-skill individuals showed a positive slow wave when solving medium and large problems. Given that differences between high and low skill individuals have been related to differences in calculation strategies, these results provide further support to the utility of using ERP as a signature of arithmetic strategy.

Social exclusion in middle childhood: Rejection events, slow-wave neural activity, and ostracism distress

This study examined neural activity with event-related potentials (ERPs) in middle childhood during a computer-simulated ball-toss game, Cyberball. After experiencing fair play initially, children were ultimately excluded by the other players. We focused specifically on “not my turn” events within fair play and rejection events within social exclusion. Dense-array ERPs revealed that rejection events are perceived rapidly. Condition differences (“not my turn” vs. rejection) were evident in a posterior ERP peaking at 420 ms consistent, with a larger P3 effect for rejection events indicating that in middle childhood rejection events are differentiated in <500 ms. Condition differences were evident for slow-wave activity (500–900 ms) in the medial frontal cortical region and the posterior occipital–parietal region, with rejection events more negative frontally and more positive posteriorly. Distress from the rejection experience was associated with a more negative frontal slow wave and a larger late positive slow wave, but only for rejection events. Source modeling with Geosouce software suggested that slow-wave neural activity in cortical regions previously identified in functional imaging studies of ostracism, including subgenual cortex, ventral anterior cingulate cortex, and insula, was greater for rejection events vs. “not my turn” events.

Spatial cueing in time–space synesthetes: An event-related brain potential study

Some people report that they consistently and involuntarily associate time events, such as months of the year, with specific spatial locations; a condition referred to as time–space synesthesia. The present study investigated the manner in which such synesthetic time–space associations affect visuo-spatial attention via an endogenous cuing paradigm. Reaction times and ERPs were recorded as 12 time–space synesthetes and 12 control participants did a peripheral target detection task, cued by three different types of centrally presented cues: arrows pointing left or right, direction words “left” or “right”, and month names associated with either the left or the right side of the synesthete’s mental calendar (e.g., “October” or “May”). Cues were followed by probes on the left or right side of the screen, and participants responded to the probes with button presses. Behavioral and ERP data suggested that for synesthetes, month words functioned more effectively as cues to direct attention in space. In synesthetes but not controls, a comparison of ERPs to probes cued by months revealed effects of cue validity on the P3b component peaking 370 ms post-onset and on the subsequent positive slow wave (pSW) observed 600–900 ms post-onset (both larger for invalid probes). No effects of cue validity were observed on early visual potentials (N1) for probes cued by months. The findings suggest that in these time–space synesthetes cue validity influenced post-perceptual processes, such as stimulus evaluation and categorization, with no evidence for enhanced visual processing.

Unexpected action effects elicit deviance-related brain potentials and cause behavioral delay

To examine how people deal with perceivable consequences of their voluntary actions, we recorded event-related potentials (ERPs) during a self-paced, two-choice random generation task. Sixteen participants were asked to press one of two buttons randomly at a regular but self-selected interval of once per 1-2 s. Each button press produced either a 1000-Hz or 2000-Hz tone, but participants were told that the tones were irrelevant to the task. The button-tone combinations were initially fixed, but in subsequent blocks, a button press infrequently produced the tone associated with the opposite button (p=.15). This cognitively mismatched tone elicited N2, P3, and late positive potential (or positive slow wave) of the ERP and delayed the timing of the next button press. These results suggest that action effects are difficult to ignore and that an action effect that is different from a performer's expectation may cause task disruption.

Event-related brain potentials during the standard autonomic-based concealed information test

The concealed information test (CIT) has been used to detect information that examinees possess by means of their autonomic responses. However, the central activities related to these autonomic responses remain unclear. In this study, we simultaneously recorded 128-ch event-related potentials (ERPs) and various autonomic responses (heart rate, respiratory rate, respiratory amplitude, cutaneous blood flow, and skin conductance response) to a critical item (i.e., the item that participants memorized) and to non-critical items (i.e., items other than the critical item) using the standard protocol of the autonomic-based CIT. A topographic analysis of variance and a temporal–spatial principal component analysis revealed that the critical item elicited a larger negative potential (N2b, 205–298 ms) at central regions and a larger positive potential (positive slow wave, 502–744 ms) at parieto-occipital regions, compared to the non-critical items. Correlation analysis across 21 participants showed a significant correlation between N2b increase and heart rate deceleration in response to critical items compared to non-critical items, but there were no autonomic correlates of the positive slow wave. The results suggest that at least two brain processes are involved in the autonomic-based CIT: The first is an attentional-orienting process that facilitates the processing of critical items, to which heart rate deceleration was linked, and the second is an additional process after the identification of critical items.

Neural Representation of Transposed Melody in Infants at 6 Months of Age

We examined adults' and 6-month-old infants' event-related potentials in response to occasional changes (deviants) in a 4-note melody presented at different pitch levels from trial to trial. In both groups, responses to standard and deviant stimuli differed significantly; however, adults produced a typical mismatch negativity (MMN), whereas 6-month-old infants exhibited a slow positive wave. We conclude that 6-month-old infants, like adults, encode melodic information in terms of relative pitch distances, but that the underlying cortical activity differs significantly from that of adults.

Electrophysiological responses to auditory novelty in temperamentally different 9‐month‐old infants

Behavioral reactivity to novel stimuli in the first half-year of life has been identified as a key aspect of early temperament and a significant precursor of approach and withdrawal tendencies to novelty in later infancy and early childhood. The current study examines the neural signatures of reactivity to novel auditory stimuli in 9-month-old infants in relation to prior temperamental reactivity. On the basis of the assessment of behavioral reactivity scores at 4 months of age, infants were classified into groups of high negatively reactive and high positively reactive infants. Along with an unselected control group, these groups of temperamentally different infants were given a three-stimulus auditory oddball task at 9 months of age which employed frequent standard and infrequent deviant tones as well as a set of complex novel sounds. In comparison to high positively reactive and control infants, high negatively reactive infants displayed increased amplitude of a positive slow wave in the ERP response to deviant tones compared to standard tones. In contrast, high positively reactive infants showed a larger novelty P3 to the complex novel sounds. Results are discussed in terms of optimal levels of novelty for temperamentally different infants.

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

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

Duration Magnitude and Memory Resource Demand

Whether duration magnitude modulates the cognitive resources required to represent that duration in memory is a fundamental question about the cognitive architecture of interval timing. The amplitudes of the Event-Related Potential (ERP) Slow Waves (SWs) elicited when participants maintain representations of different durations (e.g., 1500 versus 3000 ms) in memory may provide an answer to this question because increased positive SWs have been associated with increased working memory demands in studies of verbal and spatial memory. Here, participants judged whether a probe stimulus (S2) was the same duration as the preceding sample stimulus (S1). SWs recorded during a 2 s delay interval between S1 and S2 presentation were significantly more positive in the 3000 ms condition than in the 1500 ms condition, particularly at frontal-central electrode locations. This result suggests that the magnitude of the duration to be remembered influences the cognitive resources required to represent that duration in working memory.

Development of infant mismatch responses to auditory pattern changes between 2 and 4 months old

In order to process speech and music, the auditory cortex must learn to process patterns of sounds. Our previous studies showed that with a stream consisting of a repeating (standard) sound, younger infants show an increase in the amplitude of a positive slow wave in response to occasional changes (deviants) in pitch or duration, whereas older infants show a faster negative response that resembles mismatch negativity (MMN) in adults (Trainor et al., 2001, 2003; He et al., 2007). MMN reflects an automatic change-detection process that does not require attention, conscious awareness or behavioural response for its elicitation (Picton et al., 2000; Näätänen et al., 2007). It is an important tool for understanding auditory perception because MMN reflects a change-detection mechanism, and not simply that repetition of a stimulus results in a refractory state of sensory neural circuits while occasional changes to a new sound activate new non-refractory neural circuits (Näätänen et al., 2005). For example, MMN is elicited by a change in the pattern of a repeating note sequence, even when no new notes are introduced that could activate new sensory circuits (Alain et al., 1994, 1999;Schröger et al., 1996). In the present study, we show that in response to a change in the pattern of two repeating tones, MMN in 4-month-olds remains robust whereas the 2-month-old response does not. This indicates that the MMN response to a change in pattern at 4 months reflects the activation of a change-detection mechanism similarly as in adults.

Effects of training on the arithmetic problem-size effect: an event-related potential study

This study uses event-related brain potentials to examine the extent to which training in arithmetic calculation increases problem-solution associative strength and reduces the problem-size effect. Participants were presented with a classic equality verification task in two sessions. The problem size was manipulated by using small, medium and large problems. Since the problem-size effect has been related to a modulation of a late positive slow wave and explained in terms of differential frequency of use with problems, practice was expected to modify the amplitude of this positive component. Results showed that the amplitude of the positive slow wave increased with problem size and decreased with practice, suggesting that practice is an important determinant of the problem-size effect.

The effect of visual sexual content on the event-related potential

In the present study we investigated the effect of emotional valence and arousal value of non-erotic visual stimuli on event-related potentials. We also directly compared the effects of erotic and non-erotic stimuli of comparable valence and arousal levels. Sixteen sexually functional heterosexual males rated 150 computer screen pictures, selected from the International Affective Picture System, representing five stimulus types differing along dimensions of emotional valence and arousal, and erotic vs. non-erotic content. A positive deflection of the ERP between 300 and 500ms after stimulus onset (P300) was found to be sensitive to stimulus differences, with positive valence and high arousal resulting in larger P300. Furthermore, the positive slow wave (PSW) between 500 and 750ms revealed additive effects of valence and arousal value. High arousal and positive valence of the stimuli resulted in larger PSW. Importantly, an interaction effect was absent here. In addition, sexual content led to a larger P300 and PSW than expected on the basis of a mere additive contribution of high arousal and positive valence.

The Neural Responses to Feedback Information Produced by Self-generated or Other-generated Decision Making: An ERPs Study

Event Abstract Back to Event The Neural Responses to Feedback Information Produced by Self-generated or Other-generated Decision Making: An ERPs Study Atsuhito Toyomaki1*, Y. Takahashi1, I. Kusumi1, N. Hashimoto1 and T. Koyama1 1 Department of Psychiatry, Hokkaido University, Japan Introduction: Schizophrenia is psychosis characterized by delusion and hallucination. In particular delusion of control is that of being controlled, a delusion in which one experiences one's feelings, impulses, thoughts, or actions as not one's own, but as being imposed on by some external force. It is possible that schizophrenia patients show abnormal sensation to not only internal representation but also environmental changes provided by their action. The purpose of this study was to investigate the neural response to feedback information produced by self-generated or other-generated decision making. We compared the ERP waveform associated with self-involvement effect between schizophrenia patients and normal subjects during performing multiplayer game task. Methods: Eleven schizophrenia patients and 11 normal subjects participated in present study. They performed the two-choice gambling task in which feedback information was presented after response by pressing button (figure 1). In self-decision condition, participant himself had to choice and press button one of two options. In other-decision condition, other person sitting next to the participant choice one of two option and later participant was instructed to press button according to decision made by other person. In both conditions, monetary gain or loss indicated by feedback information was attributed to participant. We measured event-related brain potentials to feedback stimulus and examined differences of neural responses in self-decision condition and other-decision condition. Results: In normal subjects, the neural response to feedback stimulus was obviously different between in self-decision and other-decision condition compared to those of schizophrenia patients. The positive slow wave was larger in self-decision condition than in other-decision condition. On the other hand amplitude of positive slow wave in self-decision condition in schizophrenia patients was reduced significantly compared to normal subjects (figure 2). Disscussion: The results demonstrated that schizophrenia patients show reduced neural response to feedback information produced by self-generated action. Our findings suggest that these abnormal neural substrates contribute to deficiency of "sense of agency" accompanying their own action and environmental changed produced by self-generated decision making. toyomaki-1 tn_toyomaki-2 tn_toyomaki-1 toyomaki-2 Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Poster Presentation Topic: Neuropsychiatric Disorders Citation: Toyomaki A, Takahashi Y, Kusumi I, Hashimoto N and Koyama T (2008). The Neural Responses to Feedback Information Produced by Self-generated or Other-generated Decision Making: An ERPs Study. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.366 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Dec 2008; Published Online: 15 Dec 2008. * Correspondence: Atsuhito Toyomaki, Department of Psychiatry, Hokkaido University, Sapporo, Japan, toyomaki@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Atsuhito Toyomaki Y. Takahashi I. Kusumi N. Hashimoto T. Koyama Google Atsuhito Toyomaki Y. Takahashi I. Kusumi N. Hashimoto T. Koyama Google Scholar Atsuhito Toyomaki Y. Takahashi I. Kusumi N. Hashimoto T. Koyama PubMed Atsuhito Toyomaki Y. Takahashi I. Kusumi N. Hashimoto T. Koyama Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Positive slow waves in the EEG of premature infants between 24 and 36 weeks of conceptional age

Objective The aim of this prospective and longitudinal study was to characterize EEG patterns during the first weeks of life in extremely premature infants. Methods Twenty-five extremely premature infants were included and weekly EEG recordings were obtained between 24 and 36 weeks of conceptional age (CA). Results Central (rolandic) positive slow waves (CPSW) were found to be the most reliable and characteristic pattern. CPSWs were frequent at 24 weeks CA and progressively diminished and disappeared around 34 weeks CA. CPSWs appeared isolated or in sequences, they occurred during periods of continuous or discontinuous EEG activity, during bursts or during intervals of discontinuous activity, and unilaterally or bilaterally. Temporal positive slow waves and theta rhythms occurred less often and did not decrease as a function of CA. In addition, the amount of discontinuity progressively decreased until 36 weeks CA. The duration of bursts stayed constant, while inter-burst intervals decreased as a function of CA. Conclusions Central positive slow waves are characteristic features of the EEG in the extremely premature infant. Significance The presence of CPSWs and their progressive disappearance until 34 weeks CA may represent a maturational marker in the EEG.