Age- and performance-related differences in encoding during early childhood: insights from event-related potentials

Previous studies have found that children show rapid and significant improvements in their ability to remember individual items and the contextual details that surround these items (i.e., episodic memory) during early childhood. Encoding processes have been suggested to contribute to the development of episodic memory; however, few studies have investigated encoding processes. The goal of the current study was to examine age- and performance-related effects on encoding in children between 4 and 8 years of age using event-related potentials (ERPs). Results revealed effects of both age and performance on encoding, as indexed by the ERPs response. However, the nature of these effects differed between subsequent recognition and subsequent recollection, as well as for the two ERP components (i.e., Nc and LSW) examined. These findings are important as they contribute empirical evidence that encoding processes show developmental change across early childhood. In addition, these findings highlight the importance of controlling for performance differences in future studies examining developmental changes in episodic memory.     

海洛因戒治者执行控制功能异常的电生理证据

执行控制障碍是成瘾的核心特征之一,对成瘾者的复发与康复治疗有重要影响。采用事件相关电位(ERP)技术分析海洛因戒治者和健康成年人在经典色-词Stroop任务中执行控制的大脑皮层时程动态变化。行为结果发现,两组被试的反应时均有显著的Stroop干扰效应,但无显著组间差异。ERP结果显示,戒治组不一致条件的平均波幅显著小于对照组;戒治组Stroop任务相关的N2效应和SP消失及N450效应衰减。研究结果表明,海洛因戒治者可能存在早期冲突监控加工障碍和晚期反应冲突解决加工异常。     

Neural underpinnings of the relationships between sensation seeking and emotion regulation in adolescents

There is little neurological evidence linking sensation seeking and emotion regulation in adolescence, which is characterised as an emotionally fluctuant period. The present study examined the relationship between sensation seeking and emotion regulation in adolescents. Electroencephalograms were recorded from 22 high sensation-seeking adolescents (HSSs, M_age = 12.36) and 24 low sensation-seeking adolescents (LSSs, M_age = 12.84) during the reactivity and regulation-image task. Group differences in event-related brain potentials (ERPs) associated with the regulation of negative and neutral stimuli were analysed. The results showed that (a) the P2 of HSSs were larger than LSSs during emotion regulation; (b) in down-regulation conditions, the LPP in all time windows were smaller than no-regulation in LSSs. However, there was no significant difference in HSSs; (c) the LPP 300–600 and LPP 1000–1500 of down-regulation were smaller in LSSs than HSSs; (d) for LPP 600–1000, HSSs induced larger LPP than LSSs in the negative down-regulation and negative no-regulation conditions. The results provide neurological evidence that higher sensation seeking is related to the high reactivity to emotional stimuli and poor cognitive control during the regulation of emotions.     

Brain electrical activity from encoding to retrieval while maintaining and manipulating information in working memory

ABSTRACT

Differences between working memory maintenance (Mt) and manipulation (Mp) have been studied, mostly in the absence of stimuli (delay period); encoding and retrieval phases have been less explored. The present study assessed differences between Mt and Mp, by means of event-related potentials (ERPs) and event-related synchronisation (ERS) and desynchronisation (ERD) for theta, alpha and beta bands at: encoding, delay period and retrieval; using a delayed-match to sample task (DMST). Twenty-six young volunteers solved two DMST conditions (one for Mt and one for Mp). Higher behavioural accuracy for Mt than for Mp was observed. At encoding, higher amplitude for Mt at posterior regions to N1, P2 and P3 components were observed. In the delay period, differences in ERP components and frontal theta ERD were observed. Meanwhile, at retrieval, P3 amplitude and latency, as well as the theta band were modulated by both process (Mt or Mp) and type of trial (target or non-target stimuli). These findings mainly suggest different attentional implications at encoding, differences at the delay period related with task difficulty, and differential retrieval for Mt or Mp dependent on the process which the information comes from, suggesting that Mt and Mp differ at the very beginning of the processing.     

This is your brain on violent video games: Neural desensitization to violence predicts increased aggression following violent video game exposure

Previous research has shown that media violence exposure can cause desensitization to violence, which in theory can increase aggression. However, no study to date has demonstrated this association. In the present experiment, participants played a violent or nonviolent video game, viewed violent and nonviolent photos while their brain activity was measured, and then gave an ostensible opponent unpleasant noise blasts. Participants low in previous exposure to video game violence who played a violent (relative to a nonviolent) game showed a reduction in the P3 component of the event-related brain potential (ERP) to violent images (indicating physiological desensitization), and this brain response mediated the effect of video game content on subsequent aggressive behavior. These data provide the first experimental evidence linking violence desensitization with increased aggression, and show that a neural marker of this process can at least partially account for the causal link between violent game exposure and aggression.     

Stuttering treatment control using P300 event-related potentials

Positron emission tomography studies during speech have indicated a failure to show the normal activation of auditory cortical areas in stuttering individuals. In the present study, P300 event-related potentials were used to investigate possible effects of behavioral treatment on the pattern of signal amplitude and latency between waves. In order to compare variations in P300 measurements, a control group paired by age and gender to the group of stutterers, was included in the study. Findings suggest that the group of stutterers presented a significant decrease in stuttering severity after the fluency treatment program. Regarding P300 measurements, stutterers and their controls presented results within normal limits in all testing situations and no significant statistical variations between pre and post treatment testing. When comparing individual results between the testing situations, stutterers presented a higher average decrease in wave latency for the right ear following treatment. The results are discussed in light of previous P300 event-related potentials and functional imaging studies with stuttering adults.Educational objectives: The reader will learn about and be able to describe the: (1) use of P300 event-related potentials in the study of stuttering; (2) differences between stuttering and non-stuttering adults; and (3) effects of behavioral fluency treatment on cerebral activity in stuttering speakers.     

Anarchic-hand syndrome: ERP reflections of lost control over the right hemisphere

In patients with the callosal type of anarchic-hand syndrome, the left hand often does not act as intended and counteracts the right hand. Reports are scarce about the underlying neurophysiological mechanisms. We report the case G.H. who developed the syndrome after infarction of the left arteria pericallosa. It has been suggested that the syndrome arises out of lacking inhibition from the dominant left hemisphere on the right hemisphere. Yet, in tests of spatial intelligence G.H. performed much better with his “anarchic” left hand than with his dominant right hand, similar to observations commonly reported in split-brain patients. Left-right manual choice responses and event-related EEG potentials to laterally presented stimuli were measured. Asymmetries were evident in G.H.’s behavior and EEG potentials, different from age-matched healthy participants (n = 11). His right-hand responses were fast and unaffected by incompatibility with stimulus location, whereas his left-hand responses were variable and accompanied by a large negative central-midline EEG potential, probably reflecting efforts in initiating the response. G.H.’s visual N1 component peaked earlier and was larger at the right than the left side of the scalp, and the P3 component was distinctly reduced at the right side. Both features occurred independent of side of stimulus presentation and side of responding hand. The effort indicated by the midline negativity and the asymmetrically reduced P3 might directly reflect G.H.’s lack of control on his right hemisphere’s processing. The faster visual processing of the right hemisphere suggested by the N1 asymmetry might contribute to “anarchic” processing, making the right hemisphere process stimuli before control impulses exert their effect. These neurophysiological results tend to support the split-brain account which assumes that the syndrome arises by the lack of communication between hemispheres that act according to their respective competences.     

Evidence for specificity of ERP abnormalities during response inhibition in ADHD children: A comparison with reading disorder children without ADHD

Executive function and working memory deficits are not only present in ADHD, but also in reading disorder (RD). Here, high-density ERPs were recorded during the Stop Signal Task in 53 children and adolescents: An ADHD-combined type group, a group with RD, and a healthy control group. The ADHD-C group displayed unique abnormalities of the frontal N200. Both healthy controls and RD groups showed a success-related right frontal N200 modulation, which was absent in the ADHD group. Second, for Success Inhibition trials, the ADHD-C had smaller right frontal N200 waves relative to healthy controls, while the RD group did not. In contrast, NoGo-P3 abnormalities were present both in the ADHD-C and RD groups. Impaired early response inhibition mechanisms, indexed by the frontal N200, appear to be limited to ADHD-C. In contrast, deficits in later cognitive control and error monitoring mechanisms, indexed by the NoGo-P3, appear to be present in both conditions.     

Electrophysiological changes during adolescence: A review

While psychological research has long shown that adolescence is a period of major cognitive and affective transition, recent neurophysiological research has shown that adolescence is also accompanied by observable maturational changes in the brain, both in terms of structure and neurotransmitter function. Given this situation, we would expect that there should be observable and perhaps major changes in electrocortical activity and responses. In this review, we discuss developmental reductions in EEG power and alterations in the dominant band of EEG oscillation frequency, moderated by developmental factors such as growth-related changes in grey and white matter, and in the developmental history of cognitive and sociocultural stressors. Similarly, we summarize alterations in event-related potential components reflecting stimulus processing, response monitoring, and response anticipation. We review the literature on such changes in EEG and event-related potentials during the adolescent period and summarize some of the new developments in the field as well as interpretative difficulties.     

Protective role of educational level on episodic memory aging: An event-related potential study

The aim of the present experiment was to investigate whether educational level could modulate the effect of aging on episodic memory and on the electrophysiological correlates of retrieval success. Participants were divided into four groups based on age (young vs. older) and educational level (high vs. low), with 14 participants in each group. Event-related potentials (ERP) were recorded while participants performed a word-stem cued-recall task. Age-related memory deficits were greater for the less educated individuals. Age differences in the ERP old/new effects were also modulated by the level of education. This study demonstrated that the effects of age on episodic memory and ERP correlates of retrieval success are smaller in participants with high educational levels than those with lower levels. These findings provide support for the reserve hypothesis and highlight the need to consider individual differences when studying cognitive and cerebral changes in aging.