Interrupted actions affect output monitoring and event-related potentials (ERPs)

Memory for performed and interrupted actions was measured on source recognition and source recall tests in order to investigate output monitoring (i.e., memory for actions). Event-related potentials (ERPs) were recorded during the source recognition test to provide insight into the neural basis of output monitoring (OM). Source identification and recall of performed actions was greater than interrupted actions, thereby replicating the enactment effect. Examination of memory errors revealed that interrupted actions were more often mistaken as performed actions. The ERP data indicated that brain activity elicited by performed actions differed from interrupted and new actions. A clear difference in temporal onset of two ERP effects (i.e., a central-parietal and a frontal ERP difference) was observed, and it supports the previous hypothesis that two distinct processes support OM and source monitoring judgements. The pattern of frontal ERP differences suggested that interrupted actions prompted people to use more systematic decision processes overall to make OM judgements. Central-parietal ERP effects suggested that sensori-motor information was not recollected for interrupted actions--rather OM judgements were based on cognitive operations in this case.     

Interrupted actions affect output monitoring and event-related potentials (ERPs)

Memory for performed and interrupted actions was measured on source recognition and source recall tests in order to investigate output monitoring (i.e., memory for actions). Event-related potentials (ERPs) were recorded during the source recognition test to provide insight into the neural basis of output monitoring (OM). Source identification and recall of performed actions was greater than interrupted actions, thereby replicating the enactment effect. Examination of memory errors revealed that interrupted actions were more often mistaken as performed actions. The ERP data indicated that brain activity elicited by performed actions differed from interrupted and new actions. A clear difference in temporal onset of two ERP effects (i.e., a central-parietal and a frontal ERP difference) was observed, and it supports the previous hypothesis that two distinct processes support OM and source monitoring judgements. The pattern of frontal ERP differences suggested that interrupted actions prompted people to use more systematic decision processes overall to make OM judgements. Central-parietal ERP effects suggested that sensori-motor information was not recollected for interrupted actions—rather OM judgements were based on cognitive operations in this case.     

Methodological issues in event-related brain potential research

Event-related brain potential (ERP) measures have become increasingly popular in experimental psychology and are often employed by researchers who are not formally trained in electrophysiology. A proper application of these measures requires knowledge about the methodological principles and practical issues that are relevant to ERP measurement, analysis, and interpretation. A brief introductory survey of different aspects of ERP methodology (recording, data processing and signal extraction, statistical analysis and interpretation of ERP effects) is presented, and the contributions collected in this special issue on ERP methodology are introduced.     

Event-related potentials indicate that reality monitoring differs from external source monitoring

This experiment investigated differences in event-related potentials (ERPs) observed in 2 types of source monitoring decisions. Participants discriminated between self-generated, heard, and new words (reality monitoring) in one condition; in another they discriminated between words heard in a male or female voice and new items (external source monitoring). The data support the source monitoring framework, which argues that reality monitoring discriminations differ from external source monitoring discriminations. Analysis revealed better overall source accuracy during reality monitoring than during external source monitoring. In the external source monitoring task, an early old-new ERP difference was observed at parietal electrodes followed by frontal old-new effect that persisted longer, replicating previous ERP results. However, early ERP amplitude differences between sources were observed at parietal electrode sites during reality monitoring, suggesting that self-generated items activate more differentiated information during remembering. Furthermore, there were no frontal old-new ERP differences during reality monitoring, suggesting that different decision processes are used in these types of source monitoring decisions.     

Localized measures for nonstationary time-series of physiological data

We will discuss localized measures related to the concepts of dimension, Lyapunove exponents (entropy), and recurrence diagrams. We stress the relevance of localized events and coincidences in physiological time series that often are lost when statistical averaging methods are applied. We suggest event-based statistics as an alternative to spectral or averaged-based statistics. The use of wavelets bases for characterizing localized structures is discussed as a potential alternative to Fourier-based analysis. Finally we mention how local domains in state space could be applied as triggers for external stimuli and thereby improve the statistics of ERP recordings.     

A Brief Motivational Intervention for Treatment‐Refusing OCD Patients

Cognitive behavioral therapy involving exposure and response prevention (ERP) is the psychosocial treatment of choice for obsessive‐compulsive disorder (OCD). Despite this, ERP is not widely used by mental health practitioners, and so dissemination of ERP and other empirically supported treatment (ESTs) has become a priority. Even so, utilization of ESTs such as ERP remains below 50% even among therapists who self‐identify as having a cognitive behavioral orientation. Barriers to the acceptance of ERP include practical obstacles such as lack of training and the cost of treatment, but also patient variables such as treatment refusal. It has been estimated that approximately 25% of OCD patients refuse ERP. This paper describes a brief, 4‐session readiness intervention (RI) designed to decrease ERP refusal among patients with OCD. In this study, 12 patients with OCD who had refused ERP were randomized to RI or wait‐list (WL). 86% of participants in the RI condition and 20% of participants in WL condition agreed to begin ERP following the 4‐week period. ERP following RI, but not WL, was associated with a decrease in OCD symptoms comparable to that observed in OCD patients who did not refuse ERP. However, ERP following RI was associated with a high drop‐out rate (50%), a figure that exceeds that typically seen in OCD treatment studies. Techniques to reduce drop‐out as well as directions for future research are discussed.     

A brief motivational intervention for treatment-refusing OCD patients

Cognitive behavioral therapy involving exposure and response prevention (ERP) is the psychosocial treatment of choice for obsessive-compulsive disorder (OCD). Despite this, ERP is not widely used by mental health practitioners, and so dissemination of ERP and other empirically supported treatment (ESTs) has become a priority. Even so, utilization of ESTs such as ERP remains below 50% even among therapists who self-identify as having a cognitive behavioral orientation. Barriers to the acceptance of ERP include practical obstacles such as lack of training and the cost of treatment, but also patient variables such as treatment refusal. It has been estimated that approximately 25% of OCD patients refuse ERP. This paper describes a brief, 4-session readiness intervention (RI) designed to decrease ERP refusal among patients with OCD. In this study, 12 patients with OCD who had refused ERP were randomized to RI or wait-list (WL). 86% of participants in the RI condition and 20% of participants in WL condition agreed to begin ERP following the 4-week period. ERP following RI, but not WL, was associated with a decrease in OCD symptoms comparable to that observed in OCD patients who did not refuse ERP. However, ERP following RI was associated with a high drop-out rate (50%), a figure that exceeds that typically seen in OCD treatment studies. Techniques to reduce drop-out as well as directions for future research are discussed.     

Testing reciprocity in social interactions: A comparison between the directional consistency and skew-symmetry statistics

In the present article, we focus on two indices that quantify directionality and skew-symmetrical patterns in social interactions as measures of social reciprocity: the directional consistency (DC) and skew-symmetry indices. Although both indices enable researchers to describe social groups, most studies require statistical inferential tests. The main aims of the present study are first, to propose an overall statistical technique for testing null hypotheses regarding social reciprocity in behavioral studies, using the DC and skew-symmetry statistics (Phi) at group level; and second, to compare both statistics in order to allow researchers to choose the optimal measure depending on the conditions. In order to allow researchers to make statistical decisions, statistical significance for both statistics has been estimated by means of a Monte Carlo simulation. Furthermore, this study will enable researchers to choose the optimal observational conditions for carrying out their research, since the power of the statistical tests has been estimated.     

测验范式对位置来源提取的影响—— 事件相关电位研究

采用事件相关电位方法, 通过两个实验分别考察不同测验范式(排除范式和三键范式)对图形位置来源提取头皮分布特性的影响, 以检验前人得出的测验范式对颜色来源提取ERPs影响较小的结论是否适用于其他来源类型这一问题。结果显示, 相比于项目再认, 实验一中与图形位置来源提取关联的正走向新/旧效应的头皮分布更广; 实验二则得出反映位置来源提取的晚期负走向新/旧效应。可见, 两类测验范式条件下与位置来源提取关联新/旧效应的头皮分布时空特征有所不同。上述结果表明：与颜色来源研究不同, 测验范式对位置来源提取关联的神经机制具有明显调节作用。     

An overall statistic for testing symmetry in social interactions

The present work focuses on the skew-symmetry index as a measure of social reciprocity. This index is based on the correspondence between the amount of behaviour that individuals address toward their partners and what they receive in return. Although the skew-symmetry index enables researchers to describe social groups, statistical inferential tests are required. This study proposes an overall statistical technique for testing symmetry in experimental conditions, calculating the skew-symmetry statistic (Phi) at group level. Sampling distributions for the skew-symmetry statistic were estimated by means of a Monte Carlo simulation to allow researchers to make statistical decisions. Furthermore, this study will allow researchers to choose the optimal experimental conditions for carrying out their research, as the power of the statistical test was estimated. This statistical test could be used in experimental social psychology studies in which researchers may control the group size and the number of interactions within dyads.     

Localizing cortical sources of event-related potentials in infants' covert orienting

This study used cortical source analysis to locate potential cortical sources of event-related potentials (ERPs) during covert orienting in infants aged 14 and 20 weeks. The infants were tested in a spatial cueing procedure. The reaction time to localize the target showed response facilitation for valid trials relative to invalid or neutral trials. High-density EEG (126 channels) was recorded during the task, and independent component analysis and equivalent current dipole analysis was used to estimate the cortical sources of the EEG during the task. There was a larger P1 ERP component on the valid trials than the other trials (P1 validity effect). The cortical source analysis suggested that this occurred due to activity in Brodmann's areas 18 and 19. A presaccadic ERP component occurred over the frontal scalp areas (-65 ms) and was larger to a target in a cued location than in uncued locations. A potential cortical source for this ERP component was the superior frontal gyrus on the inferior portion of the prefrontal cortex. Increases from 14 to 20 weeks in amplitude of the P1 validity effect and the presaccadic ERP could be modeled by an increase in activation in the corresponding cortical areas.     

项目间多维测验作答时间数据分析：潜在特质速度间效应建模

随着计算机测验使用的普及化,被试在心理与教育测验上的作答反应时的获取也越发便利。为了充分利用项目反应时信息,单维与多维的反应时模型相继被提出。然后,在项目间多维反应时数据中,潜在特质速度之间可能存在共同关系（比如,层阶关系）,此时现有的反应时模型并不能适用。基于此,本研究提出了高阶对数正态反应时模型与双因子对数正态反应时模型。在模拟研究中,高阶对数正态反应时模型与双因子对数正态反应时模型的各参数都能被准确估计。在瑞文标准推理测验的三组测验项目的反应时数据中,双因子对数正态反应时模型表现出更为优秀的拟合效果,同时基于多个统计量说明了局部与全局潜在特质速度同时存在的必要性。因此,在项目间多维测验反应时数据分析中,非常有必要考虑多维潜在特质速度之间的共同效应。     

Functional characterisation of the extrastriate body area based on the N1 ERP component

Electrophysiological and functional neuroimaging evidence points to the existence of neural populations that respond strongly and selectively to the appearance of the human body and its parts. However, the relationship between ERP and fMRI markers of these populations remains unclear. Here we used a previously identified functional dissociation between two body-selective regions identified with fMRI (extrastriate body area or EBA; fusiform body area or FBA) in order to better understand the source of a body-selective N1 ERP component. Specifically, we compared the magnitude of the N1 elicited by images of fingers, hands, arms and bodies to that obtained for hierarchically-matched control stimuli. We found close agreement between the pattern of body-part selectivity exhibited by N1, and the pattern of BOLD selectivity elicited in a previous study by the same type of stimuli in EBA (in contrast to FBA). We interpret these findings as evidence for EBA as the primary generator of the body-selective N1 component. Our results are an example of the use of functional criteria to distinguish among the possible neural sources of ERP markers.     

Examining the role of feedback in TMS-induced visual suppression: A cautionary tale

Visual suppression by single-pulse transcranial magnetic stimulation (sTMS) has been attributed to interruptions of either feedforward or feedback activity in the visual stream. The relative timing of the C1 event related potential (ERP) and of the TMS suppression, taken from separate studies, supports an interruption of feedback. Here we probe the validity of such cross-study comparisons, both by conducting a literature survey and by measuring each time window within participants for the same stimuli. Cortical transmission time was estimated using the C1. We then suppressed the same stimuli that elicited the C1 using sTMS of variable post-stimulus lags. Results do not conclusively discriminate between interruption of feedback or feedforward mechanisms as the source of the visual suppression. We suggest that more evidence is needed to distinguish between feedback and feedforward interference in TMS suppression effects and we advise caution in making inferences derived from separate literatures, using different stimuli.     

Source Monitoring: ERP Evidence for Greater Reactivity to Nontarget Information in Older Adults

Event-Related Potentials (ERPs) were collected concurrently with stimulus presentation during a source monitoring task. Younger adults were less likely than older adults to make source monitoring errors and their ERP records showed far greater discrimination between target stimuli and familiar but nontarget foils. Older adults not only made more source errors but produced high amplitude late positivities to the nontarget foils even when these foils were correctly rejected. Under divided attention conditions, younger adults performance was similar to that of the older adults both behaviorally and electrophysiologically. These data illustrate the role that attentional resources play in the ability to inhibit response tendencies and suggest that age differences in source monitoring may be more related to attentional control than inefficiencies in the encoding of contextual information. As well, they suggest that the ERP late positivity may represent a more general response to item salience rather than serve as an index of recollection as is the current view.     

Issues in the application of the average reference: Review, critiques, and recommendations

In standard event-related potential (ERP) recordings, activity at the reference site affects measurements at all the “active” electrode sites. Analyses of ERP data would be improved if reference site activity could be separated out. Apart from current source density methods, which can miss deep or distributed events, the major alternative to an “indifferent” electrode reference is one that combines all active electrodes, subtracting out the activity common to all of them. The average reference has merits (such as an insensitivity to scalp currents near any single electrode) and limitations (such as a dependence on the number and locations of all the electrodes in the average). This review compares the effects of different references on the scalp topography of the auditory N1 recorded with an array of 128 electrodes. Furthermore, it shows how assumptions associated with each reference affect inferential methods such as analysis of variance and correlation. Finally, it seeks to evaluate the efficacy of the average reference in estimating the true zero potential line.     

The effects of age on the neural correlates of successful episodic retrieval: An ERP study

The neural correlates of successful episodic retrieval (recollection), as reflected in event-related potentials (ERPs), were investigated in young (ca. 20 years; n=18) and older (ca. 70 years; n=16) healthy individuals. Subjects classified a series of pictures according to whether each item was new or had been encountered at study in the context of an animacy or a size judgment task. By manipulating the number of times items were presented for study, subsets of test items were formed for which source accuracy did not differ according to age. Relative to ERPs elicited by unstudied pictures, ERPs elicited by items attracting equivalent levels of source accuracy showed marked age-related differences. Those from younger subjects demonstrated the positive-going left parietal and right frontal old/new effects described in several previous studies of source memory. By contrast, analogous ERPs from older subjects contained a large left-lateralized negative effect that overshadowed the positive-going effects evident in the young. No age-related differences in either parietal or frontal ERP old/new effects were detected at electrode sites overlying the right hemisphere. It is possible that the age-related ERP differences observed in this task primarily reflect the use of different kinds of information as a basis for source judgments.     

Event-related potential (ERP) evidence for varied recollection during source monitoring

The source monitoring framework (SMF; M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993) posits that source monitoring can be supported by varying degrees of recollection. Source judgments were made for words heard at study (male or female voice) followed by remember/know (RK) judgments in order to assess differences in degrees of recollection during source monitoring (J. L. Hicks, R. L. Marsh, & L. Ritschel, 2002). The neural correlate of recollection was examined by contrasting event-related potentials (ERPs) for R and K responses that followed accurate source judgments. The recollection ERP effect was greater for R than K responses but greater for K responses than correct rejections, which reinforces the behavioral evidence that indicates source monitoring can be supported by varying degrees of recollection. A robust late posterior negativity ERP effect was present and began earlier for accurate source judgments given subsequent R than K responses. This is interpreted as reflecting systematic decision processes that are described by the SMF.     

锚定判断中的心理刻度效应：来自ERP的证据

当前主要有两种理论解释锚定效应的发生机制：锚定调整启发模型和选择通达模型。同样,锚值可能是自发产生的,也可能是外部提供的。本研究用两个ERP实验分别探讨了不同精细程度的心理刻度对自发锚定加工和外部锚定加工的影响。结果表明,只有在自发锚引起的锚定加工中才出现心理刻度效应：在目标呈现后250~800ms之间,精细心理刻度比粗糙心理刻度诱发一个更大的波形正走向,支持锚定调整启发模型。在外部锚引起的锚定加工中,没有出现心理刻度效应,却出现了一个与通达有关的N300成分,支持选择通达加工模型。总的结果支持了锚定加工的双重属性：锚定判断是主动调整还是选择通达取决于不同的情境     

Relationships between event‐related potentials and behavioral and scholastic measures of reading ability: A large‐scale,cross‐sectional study

In the cognitive, computational, neuropsychological, and educational literatures, it is established that children approach text in unique ways, and that even adult readers can differ in the strategies they bring to reading. In the developmental event‐related potential (ERP) literature, however, children with differing degrees of reading ability are, the majority of the time, placed in monolithic groups such as ‘normal’ and ‘dyslexic’ (e.g. Araújo et al., 2012) and analyzed only at the group level. This is likely done due to methodological concerns – such as low sample size or a lack of statistical power – that can make it difficult to perform analysis at the individual level. Here, we collected ERPs and behavior from > 100 children in grades pre‐K–7, as they read unconnected text silently to themselves. This large sample, combined with the statistical power of the Linear Mixed Effects Regression (LMER) technique, enables us to address individual differences in ERP component effects due to reading ability at an unprecedented level of detail. Results indicate that it is possible to predict reading‐related report card scores from ERP component amplitudes – especially that of the N250, a component pertaining to sublexical processing (including phonological decoding). Results also reveal relationships between behavioral measures of reading ability and ERP component effects that have previously been elusive, such as the relationship between vocabulary and N400 mean amplitude (cf. Henderson et al., 2011). We conclude that it is possible to meaningfully examine reading‐related ERP effects at the single subject level in developing readers, and that this type of analysis can provide novel insights into both behavior and scholastic achievement.