Search

There is an ongoing debate on how different components of the event‐related potential (ERP) to threat‐related facial expressions are modulated by attentional conditions and interindividual differences in trait anxiety. In the current study (N = 80), we examined ERPs to centrally presented, task‐irrelevant fearful and neutral faces, while participants had to solve a face‐unrelated visual task, which differed in difficulty and spatial position. Critically, we used a fixation‐controlled experimental design and ensured the spatial attention manipulation by spectral analysis of the EEG. Besides the factors emotion, spatial attention, and perceptual load, we also investigated correlations between trait anxiety and ERPs. While P1 emotion effects were insignificant, the N170 was increased to fearful faces regardless of load and spatial attention conditions. During the EPN time window, a significantly increased negativity for fearful faces was observed only during low load and spatial attention to the face. We found no significant relationship between ERPs and trait anxiety, questioning the hypothesis of a general hypersensitivity toward fearful expressions in anxious individuals. These results show a high resistance of the N170 amplitude increase for fearful faces to spatial attention and task load manipulations. By contrast, the EPN modulation by fearful faces index a resource‐dependent stage of the ERP, requiring both spatial attention at the location of faces and low load of the face‐irrelevant task. The human brain responds differentially to fearful expressions. It remains unclear how and when attentional constraints attenuate differential processing. We systematically tested how spatial attention, task load, and trait anxiety affect neuronal processing to resolve this question. We found that early (N170) ERP responses to fearful faces were independent of attention task manipulations, in contrast to a subsequent resource‐dependent processing stage (EPN). Further, we found no significant relationship between ERP responses and trait anxiety, questioning the hypothesis of a general hypersensitivity toward fearful expressions in anxious individuals. [ABSTRACT FROM AUTHOR]

Response conflict evoked by a distractor stimulus object in interference tasks is associated with longer reaction times and a pronounced ERP component referred to as the fronto‐central N2. Increasing the proportion congruency (PC, i.e., the proportion of trials in which target and distractor are associated with the same response) is assumed to enhance distractor‐evoked conflict via defocusing of attention. Findings concerning the effect of the PC on the N2 in Eriksen flanker task experiments have been inconsistent, however, lending little support to the notion that the N2 reflects a conflict monitoring process. Here, we analyze the N2 in a temporal flanker task, in which the distractor stimuli, presented in advance of the target, elicit pronounced activation of the associated responses (as inferred from the lateralized readiness potential) when the PC is high. Consistent with result pattern obtained in other tasks involving successive presentation of the distractor and the target, conflict trials in a high‐PC condition evoked a particularly large N2. These findings accord with the assumption that the N2 reflects either conflict monitoring or conflict‐induced regulatory measures (i.e., reactive control). In light of the discrepancy of results obtained under conditions of simultaneous and successive distractor–target presentation, we speculate that the N2 is pronounced in situations that offer strong hints for classifying dominating response activation as incorrect, possibly reflecting particular control to counter this activation. Additional properties of the temporal flanker task, related to ERP investigations, are discussed. We present novel evidence concerning the role of the fronto‐central N2 in conflict tasks. Although our results meet the predictions of a conflict monitoring account, they suggest particular sensitivity of the N2 to dominance of (discernibly) incorrect response activation. This may be helpful in reconciling discrepant findings of proportion congruency modulations obtained with different types of conflict tasks. [ABSTRACT FROM AUTHOR]

Visual search is speeded when a target item is positioned consistently within an invariant (repeatedly encountered) configuration of distractor items ("contextual cueing"). Contextual cueing is also observed in cross‐modal search, when the location of the—visual—target is predicted by distractors from another—tactile—sensory modality. Previous studies examining lateralized waveforms of the event‐related potential (ERP) with millisecond precision have shown that learned visual contexts improve a whole cascade of search‐processing stages. Drawing on ERPs, the present study tested alternative accounts of contextual cueing in tasks in which distractor‐target contextual associations are established across, as compared to, within sensory modalities. To this end, we devised a novel, cross‐modal search task: search for a visual feature singleton, with repeated (and nonrepeated) distractor configurations presented either within the same (visual) or a different (tactile) modality. We found reaction times (RTs) to be faster for repeated versus nonrepeated configurations, with comparable facilitation effects between visual (unimodal) and tactile (crossmodal) context cues. Further, for repeated configurations, there were enhanced amplitudes (and reduced latencies) of ERPs indexing attentional allocation (PCN) and postselective analysis of the target (CDA), respectively; both components correlated positively with the RT facilitation. These effects were again comparable between uni‐ and crossmodal cueing conditions. In contrast, motor‐related processes indexed by the response‐locked LRP contributed little to the RT effects. These results indicate that both uni‐ and crossmodal context cues benefit the same, visual processing stages related to the selection and subsequent analysis of the search target. Current theories of the memory‐guided search almost entirely draw on findings from unisensory visual search tasks. By tracking preattentive and postselective attentional processes in milliseconds precisions in uni‐ and cross‐modal search, our results provide new evidence that both visual and tactile context cues benefit the same, visual processing stages related to the selection and subsequent analysis of the search target, supporting a single, supramodal mechanism underlying contextual cueing. [ABSTRACT FROM AUTHOR]

We examined the effect of combined top‐down and bottom‐up attentional control sources, using known attention‐related EEG components that are thought to reflect target selection (N2pc) and distractor suppression (PD). We used endogenous cues (valid vs. neutral) for top‐down attentional control, and salience in the form of color singletons (either the target or a distractor) for bottom‐up attentional control in visual search. Crucially, in two experiments, the task was of increasing difficulty, reporting the orientation of a tilted target (Experiment 1), or the position of a small gap within the target among tilted non‐targets (Experiment 2). Our results showed strong cueing effects on RT and accuracy in both experiments, demonstrating a general facilitation of responses to validly cued targets. Whereas the processing of salient targets was not improved compared with non‐salient targets, the presence of a salient distractor consistently worsened performance. The N2pc and PD were only observed in trials where targets were preceded by neutral cues in Experiment 1, and for validly cued targets and salient neutrally cued targets in Experiment 2. A cueing effect was found on the PD in Experiment 1, showing an amplitude reduction in trials where the target was validly cued. These results support the idea that bottom‐up attentional allocation occurs only when top‐down allocation of attention is absent or inefficient. Therefore, these results indicate that attentional selection and suppression during visual search are both influenced by top‐down cueing and give support to theories that focus on the interaction between the two types of attention. Our study provides an extensive examination of the combination of top‐down attentional guidance via endogenous cues and bottom‐up attentional allocation by salience. Our findings demonstrate the interaction between these sources as reflected in EEG markers related to selection (N2pc) and distractor suppression (PD). Critically, we demonstrate that bottom‐up capture of attention is enabled when top‐down guidance is inefficient as a result of task difficulty. [ABSTRACT FROM AUTHOR]

Losses usually have greater subjective value (SV) than gains of equal nominal value but often cause a relative deterioration in effortful performance. Since losses and gains induce differing approach/avoidance behavioral tendencies, we explored whether incentive type interacted with approach/avoidance motor‐sets. Alpha‐ and beta‐band event‐related desynchronization (ERD) was hypothesized to be weakest when participants expected a loss and prepared an inhibitory motor‐set, and strongest when participants expected a gain and prepared an active motor‐set. It was also hypothesized that effort would modulate reward and motor‐set–related cortical activation patterns. Participants completed a cued Go/NoGo task while expecting a reward (+10p), avoiding a loss (−10p), or receiving no incentive (0p); and while expecting a NoGo cue with a probability of either.75 or.25. Pre‐movement alpha‐ and beta‐band EEG power was analyzed using the ERD method, and the SV of effort was evaluated using a cognitive effort discounting task. Gains incentivized faster RTs and stronger preparatory alpha band ERD compared to loss and no incentive conditions, while inhibitory motor‐sets resulted in significantly weaker alpha‐band ERD. However, there was no interaction between incentive and motor‐sets. Participants were more willing to expend effort in losses compared to gain trials, although the SV of effort was not associated with ERD patterns or RTs. Results suggest that incentive and approach/avoidance motor tendencies modulate cortical activations prior to a speeded RT movement independently, and are not associated with the economic value of effort. The present results favor attentional explanations of the effect of incentive modality on effort. This study investigates the effect of gains and losses on cognitive effort using pre‐movement event‐related desynchronization to measure attention and approach/avoidance motor tendencies. The results showed, for the first time, that approach/avoidance motor tendencies act independently of incentive modality, and that monetary gains contributed to improved effortful performance through increased attentional engagement. [ABSTRACT FROM AUTHOR]

Previous event‐related potential (ERP) studies have suggested that self‐related and non‐self‐related outcomes are processed simultaneously. However, the studies investigated situations in which individuals had sufficient attentional/cognitive resources to process both of the outcomes. It is unknown whether self‐related and non‐self‐unrelated outcomes could still be processed simultaneously when resources are limited. To address this issue, 32 female participants in the present study were asked to perform a working memory task. To manipulate the amount of available attentional/cognitive resources, participants were asked to memorize a letter in the low load condition and five letters in the high load condition. During letter consolidation, participants were informed that they and another player each performed a gambling task and were subsequently presented with both of the outcomes. ERP results showed that others' monetary loss elicited larger P200 and late positive potential amplitudes than others' monetary gain under a low working memory load, whereas a high load reduced these effects. However, working memory load did not influence the effect of self‐outcome on ERP responses. Therefore, the findings suggest that the amount of available attentional/cognitive resources alters the evaluation of non‐self‐related but not self‐related outcomes. The current results are consistent with theories and literatures regarding outcome evaluations, in which the valence of the outcome can be evaluated irrespective of whether the outcome is self‐related or not. More importantly, we complement previous theories and literatures by demonstrating that the amount of attentional/cognitive resources alters the evaluations involving non‐self‐related outcomes but not self‐related outcomes. [ABSTRACT FROM AUTHOR]

Error‐related negativity (ERN), an electroencephalogram (EEG) component following an erroneous response, has been associated with the subjective motivational relevance of error commission. A smaller EEG event, the correct response negativity (CRN), occurs after a correct response. It is unclear why correct behavior evokes a neural response similar to error commission. CRN might reflect suboptimal performance: in tasks where speed is motivationally relevant (i.e., incentivized), a correct but slow response may be experienced as a minor error. The literature is mixed on the relationship between CRN and response time (RT), possibly due to different motivational structures, tasks, or individual traits. We examined ERN and CRN in a go/no‐go task where correctness and speed were encouraged using a points‐based feedback system. A key individual trait, regulatory focus, describes a person's tendency to seek gains (promotion focus) and avoid losses (prevention focus). Trait regulatory focus was measured, and participants were randomly assigned to one of three conditions: points gain, points loss, and informative‐only feedback. Participants committed too few errors to reliably model ERN effects. CRN amplitude related to RT in all feedback conditions, with slower responses having larger CRN. Participants with stronger promotion focus had a more exaggerated RT/CRN relationship in the point gain condition, suggesting that regulatory fit influences the motivational relevance of speed and thus the negative subjective experience and CRN for slower responses. These findings are consistent with the claim that CRN reflects RT when RT is motivationally relevant and that the CRN/RT relationship reflects the degree of subjective motivational relevance. Our findings show that larger correct response negativities are associated with slower responses in a task with explicit response time feedback. Using regulatory fit theory, we further show that the correct response negativity reflects subjective motivational value from regulatory fit between promotion orientation strength and feedback framed as point gains. These findings suggest that correct response negativity reflects response time when response time is motivationally relevant. [ABSTRACT FROM AUTHOR]

When comparing the digits of different physical sizes, the processing of numerical value interacts with the processing of physical size. Given the universal use of Arabic numbers in mathematics and daily life, this study aims to elucidate the cognitive processes involved in the interactions of task‐relevant and task‐irrelevant features during information processing. We investigated this question by examining event‐related potential (ERP) using a modified version of the size congruity comparison, which is a Stroop‐like task. Numerical value and physical size were varied independently under task‐relevant and task‐irrelevant conditions. To better examine how the task‐irrelevant features modulated the processing of the task‐relevant attributes, a neutral condition was included in both tasks. For the physical task, congruent trials showed a less negative N200 response than neutral trials (indicating a facilitation effect), and incongruent trials elicited a larger N450 and smaller late positive complex (LPC) response than neutral trials (indicating an interference effect). For the numerical task, congruent trials showed a larger LPC response than neutral trials (indicating a facilitation effect). These ERP findings indicate that the sources of the facilitation and interference effects appear in different cognitive processes for each task. We further suggest that language characteristics may be a factor in the superior numerical processing exhibited in this study. When comparing the digits of different physical sizes, the processing of numerical value interacts with the processing of physical size. However, how the above two types of quantity interact during information processing remains unclear. In this study, we investigated how number and size interact in a numerical Stroop paradigm with native Chinese speakers. Our ERP findings indicate that the sources of the facilitation and interference effects appear at multiple stages of perceptual and response processing in both numerical and physical tasks. We further suggest that language characteristics may be a factor in the superior numerical processing exhibited in this study. [ABSTRACT FROM AUTHOR]

Previous event‐related potential (ERP) studies mainly from the present research group showed a novel component, that is, the prefrontal negativity (pN), recorded in visual‐motor discriminative tasks during the pre‐stimulus phase. This component is concomitant to activity related to motor preparation, that is, the Bereitschaftspotential (BP). The pN component has been reported in experiments based on the visual modality only; for other modalities (acoustic and/or somatosensory) the presence of the pN warrants further investigation. This study represents a first step toward this direction; indeed, we aimed at describing the pN and the BP components in discriminative response tasks (DRTs) for three sensory modalities. In experiment 1 ERPs were recorded in 29 adults in visual and auditory DRT; an additional group of 15 adults participated to a somatosensory DRT (experiment 2). In line with previous results both the pN and the BP were clearly detectable in the visual modality. In the auditory modality the prefrontal pN was not detectable directly; however, the pN could be derived by subtraction of separate EEG traces recorded in a "passive" version of the same auditory task, in which motor responses were not required. In the somatosensory modality both the pN and the BP were detectable, although with lower amplitudes with respect to other two sensory modalities. Overall, regardless of the sensory modality, anticipatory task‐related pN and BP components could be detected (or derived by subtraction) over both the prefrontal and motor cortices. These results support the view that anticipatory processes share common components among sensory modalities. The novelty of this ERP study is represented by evidence of similar anticipatory brain activities supporting the decision to either act or inhibit in tasks involving target and no‐target stimuli among different sensory modalities. Findings are relevant in light of the interactions between modality‐specific and modality‐independent components of the brain's preparation to optimize upcoming performance and are consistent with Bayesian predictive models of cognition. [ABSTRACT FROM AUTHOR]

Interindividual variations in the ability to perform visuospatial mental transformations have been investigated extensively, in particular through mental rotation tasks. However, the impact of early visual processes on performance has been largely ignored. To clarify this issue, we explored the time‐course of early visual processing (from 0 to 450 ms poststimulus) using event‐related potentials topographic analyses. The main findings demonstrated a significant link between early attentional processes and accuracy scores occurring more than five seconds later, as well as a strong association between spatial covariance and microstate topographies exhibiting substantial gender differences. More specifically, the results indicated that, in a classical mental rotation task, the male brain expends more time processing visual‐spatial information resulting in a longer bilateral positive potential at posterior‐occipital sites. In comparison, the female brain initiates earlier processing of non‐spatial information resulting in a faster transition from a bilateral positive potential of posterior‐occipital sites to a negative potential at central‐frontal sites. These findings illustrate how a more complete utilization of the spatiotemporal information contained in EEG recordings can provide important insights about the impact of early visual processes on interindividual differences, particularly across gender, and thus shed new light on alternate cognitive strategies. Our research complements previous studies exploring interindividual variability in visuospatial transformations by examining the early stages of perceptual and attentional processes between men and women during mental rotation. Using event‐related potentials topographic analyses, we provide important insights about the electrical dynamics underpinning interindividual differences in demonstrating a significant link between early attentional processes and performance scores. [ABSTRACT FROM AUTHOR]

This study investigates the neural correlates underpinning response inhibition using a parametric ex‐Gaussian model of stop‐signal task performance, fit with hierarchical Bayesian methods, in a large healthy sample (N = 156). The parametric model accounted for both stop‐signal reaction time (SSRT) and trigger failure (i.e., failures to initiate the inhibition process). The returned SSRT estimate (SSRTEXG3) was attenuated by ≈65 ms compared to traditional nonparametric SSRT estimates (SSRTint). The amplitude and latency of the N1 and P3 event‐related potential components were derived for both stop‐success and stop‐failure trials and compared to behavioral estimates derived from traditional (SSRTint) and parametric (SSRTEXG3, trigger failure) models. Both the fronto‐central N1 and P3 peaked earlier and were larger for stop‐success than stop‐failure trials. For stop‐failure trials only, N1 peak latency correlated with both SSRT estimates as well as trigger failure and temporally coincided with SSRTEXG3, but not SSRTint. In contrast, P3 peak and onset latency were not associated with any behavioral estimates of inhibition for either trial type. While the N1 peaked earlier for stop‐success than stop‐failure trials, this effect was not found in poor task performers (i.e., high trigger failure/slow SSRT). These findings are consistent with attentional modulation of both the speed and reliability of the inhibition process, but not for poor performers. Together with the absence of any P3 onset latency effect, our findings suggest that attentional mechanisms are important in supporting speeded and reliable inhibition processes required in the stop‐signal task. This is the first study to examine the relationship between stop‐signal ERPs and estimates of stop‐signal task performance derived using a parametric ex‐Gaussian model fit with hierarchical Bayesian methods. In 156 adolescents and young adults, trigger failure and stop‐signal reaction time were associated with the latency and the amplitude of the stop‐N1—an early attentionally sensitive component. In contrast, model parameters were not associated with variability in P3 peak or onset latency. These findings highlight the importance of early attention processes for response inhibition. [ABSTRACT FROM AUTHOR]

Recent event‐related potential (ERP) studies have suggested that the N140cc component reflects target selection mechanisms in tactile search tasks in which the target is presented simultaneously with homogeneous distractors. To investigate if and how the attentional selection of the tactile target is affected by the presence of a singleton distractor, we presented a four‐item search array (two stimuli to the middle and index fingers of the left and right hand) which included a singleton distractor in addition to the target and two other homogenous distractors. Participants had to localize the target (top or bottom finger on either hand), while ignoring all distractors. Behavioral results revealed that the target localization was hindered by the presence of the singleton distractor as demonstrated by distractor‐presence costs for both speed and accuracy. ERP results confirmed that attention was directed to the singleton distractor when this was the only singleton item in the array as suggested by the presence of a distractor‐related N140cc component on distractor only trials. Furthermore, when target and singleton distractor were presented to opposite hands (contralateral distractor trials) the target‐related N140cc amplitude was reduced as compared to target only trials, suggesting reduced attentional resources to the target. However, when target and singleton distractor were presented to the same hand (ipsilateral distractor trials), the N140cc amplitude was comparable to that observed on target only trials. These findings suggest that the N140cc reflects the attentional selection of the target side rather than the competition between stimuli presented to the same hand. The N140cc component has been recently characterized as the electrophysiological correlate of target selection in tactile search tasks and the functional equivalent of the visual N2pc. Our results provide initial evidence that, unlike the N2pc, the N140cc components reflects primarily the allocation of attention to the side of relevant stimuli, rather than the resolution of competitive target‐distractor interactions within that side. [ABSTRACT FROM AUTHOR]

Laboratory tasks used to elicit a cardiovascular stress response in the laboratory can involve either active or passive coping. However, in previous work, passive stress tasks often incorporate a distinct physical stress element, such as the handgrip or cold pressor task, meaning observed changes in cardiovascular parameters may be the result of the physical element of the stressor rather than truly reflecting psychological stress. The present study aimed to establish the validity of a psychological passive stressor; one more analogous to active tasks than those previously employed in laboratory studies. Twenty‐six young, healthy adults completed a speech task in the laboratory following a resting baseline period. Twelve months later, they were invited back to the laboratory and watched the video recording of their speech. Analyses confirmed that while both tasks elicited significant SBP and DBP change (all ps <.001), only the active task was associated with HR and CO reactivity (both ps <.001), while only the passive task was associated with TPR reactivity (p =.028). Furthermore, the passive stressor was associated with a mixed hemodynamic profile, whereas the active stressor was associated with a clear myocardial profile. This study confirms that watching a video recording of oneself complete a speech task is associated with a more vascular response profile, a response associated with passive coping contexts. This paper reports on a laboratory study investigating the validity of a psychological passive stressor, following a traditional cardiovascular reactivity protocol. The results establish the validity of this task to invoke passive coping. This task overcomes limitations inherent in previous passive stress tasks. [ABSTRACT FROM AUTHOR]

Mind wandering during ongoing tasks can impede task performance and increase the risk of failure in the laboratory as well as in daily‐life tasks and work environments. Neurocognitive measures like the electroencephalography (EEG) offer the opportunity to assess mind wandering non‐invasively without interfering with the primary task. However, the literature on electrophysiological correlates of mind wandering is rather inconsistent. The present study aims toward clarifying this picture by breaking down the temporal dynamics of mind wandering encounters using a cluster‐based permutation approach. Participants performed a switching task during which mind wandering was occasionally assessed via thought probes applied after trial completion at random time points. In line with previous studies, response accuracy was reduced during mind wandering. Moreover, alpha power during the inter‐trial interval was a significantly increased on those trials on which participants reported that they had been mind‐wandering. This spatially widely distributed effect is theoretically well in line with recent findings linking an increased alpha power to an internally oriented state of attention. Measurements of alpha power may, therefore, be used to detect mind wandering online during critical tasks in traffic and industry in order to prevent failures. Mind wandering is highly prevalent in our daily lives and may impede task performance. In this EEG study, participants performed a switching task during which mind wandering was assessed via thought probes. A cluster‐based permutation test revealed a spatially distributed effect in terms of an increased alpha power during the inter‐trial interval when mind wandering. [ABSTRACT FROM AUTHOR]

This study examined associations of performance‐monitoring event‐related potentials (ERPs) from go/no‐go and flanker tasks with one another, and with psychopathy‐related traits of disinhibition, meanness, and boldness. A task‐dependent relationship was evident between the error‐related negativity (ERN) and trait disinhibition, with high‐disinhibited participants showing reduced no‐go ERN but not flanker ERN. Disinhibition was also inversely related to variants of the P3 and the error positivity (Pe) from these two tasks. A factor analysis of the ERPs revealed two distinct factors, one reflecting shared variance among the P3 and Pe measures from the two tasks, and the other covariance among the N2 and ERN measures. Scores on the P3/Pe factor, but not the N2/ERN factor, were inversely related to disinhibition, and accounted for associations of this trait with variants of the P3 and Pe across tasks. The implication is that high trait disinhibition relates mainly to reductions in brain responses associated with later elaborative stages in the processing of motivationally significant events across different tasks. Importantly, no‐go ERN predicted disinhibition scores beyond N2/ERN factor scores, indicating that high disinhibition is not generally related to diminished early preresponse conflict and error processing, but rather to processing impairments in conditions calling for inhibition of prepotent response tendencies. This study examined how psychopathy‐related biobehavioral traits of disinhibition, boldness, and meanness relate to performance monitoring ERPs in both a go/no‐go and a flanker task. Disinhibition showed selective associations with P3 and Pe in both tasks, and with ERN in the go/no‐go task. Findings have implications for understanding processing deviations in psychopathy. [ABSTRACT FROM AUTHOR]

Attention can be involuntarily attracted by a distractor that matches the current attentional control settings (ACSs). However, it remains unclear whether two category‐specific ACSs can operate independently. By defining a target as a combination of two prototype‐based categories, the present event‐related potential (ERP) study investigated how color‐category and shape‐category ACSs operate within a search task paradigm and the effects of temporal task demands on these ACSs. The matching level between target and distractor was manipulated to separate the effects of each ACS. The relative position between target and distractor was employed to isolate the attentional processing of the distractor from the target. Furthermore, two display durations were used to manipulate the temporal task demands, including a short fixed window (800 ms) and a dynamic window extended until the user responded. Our results support a two‐stage selection scenario. In early stage, the color‐ and shape‐ACS independently guided attention to task‐relevant property (N2pc components) and suppressed attention toward task‐irrelevant properties (PD components). In late stage, these two independent ACSs were integrated into a holistic ACS to interfere with the consolidation (contralateral delay activity components) and behavioral performance (accuracy and RTs) of target identification. Moreover, an early N1/P1 component might reflect a preattentive enhancement of relevant information or a preattentive suppression of irrelevant objects. These two category‐specific ACSs weights differently in varied temporal task demands. These findings support the idea that independent early processing is followed by integrated late processing, which can be applied to category‐based attentional capture with different temporal task demands. Although some recent research has suggested a critical role of top‐down processing for attentional capture, the current ERP study investigated how two category‐specific top‐down settings operate within a conjunction search task. The results support a two‐stage selection scenario, in demonstrating that an independent early processing (N2pc, PD) is followed by an integrated late processing (CDA, ACC, RTs). Moreover, we also found different effects of temporal task demands on the two category‐specific top‐down settings. [ABSTRACT FROM AUTHOR]

Individuals with current depression show reduced amplitude of the P300 component of the stimulus‐locked event‐related potential (ERP)—an effect most often examined in oddball tasks. Although imperative stimuli in response‐monitoring paradigms (e.g., the flanker task), also elicit a P300, it is unclear whether a blunted P300 can be observed in depression in these tasks. Moreover, the P300 overlaps with the correct‐response negativity (CRN) and error‐related negativity (ERN), and is similar to the error positivity (Pe)—response‐locked ERPs frequently examined in flanker tasks. The current study examined the stimulus‐locked P300 and response‐monitoring ERPs on error (i.e., ERN, Pe) and correct responses (i.e., CRN) during an arrowhead flanker task in 72 individuals with a current depressive disorder and 42 never depressed healthy individuals. Consistent with findings from oddball tasks, P300 amplitude was reduced among participants with depression. Further, results indicated increased ERN and CRN, and decreased Pe, in depression. However, when the blunted P300 was included in analyses, group differences in response‐monitoring ERPs were no longer evident. Accordingly, P300 amplitudes were correlated negatively with the ERN/CRN and positively with Pe in both groups. A blunted P300 in depression can be observed in speeded response tasks, and can produce apparent increases in ERN and CRN due to ERP component overlap. Further, reduced Pe in participants with depression may reflect a reduced P300 to error commission. These data highlight the central role of reduced P300 in clinical depression, and demonstrate that this effect can be observed across both stimulus‐ and response‐locked ERPs in speeded response tasks. The present study presents novel evidence regarding a significant reduction of the stimulus‐locked P300 as elicited from an Eriksen flanker task in depression. Findings suggest that a blunted P300 in depression can be observed in speeded response tasks across symptom subtypes and can produce apparent increases in ERN and CRN due to ERP component overlap. Further, reduced Pe in participants with depression may reflect a reduced P300 to error commission. [ABSTRACT FROM AUTHOR]

In order to compare processing across operations, we recorded event-related potentials ( ERPs) elicited by both problems and solutions in addition, subtraction, multiplication, and division conditions in a delayed answer verification task. Amplitudes of an early negativity, P300, and late positive component ( LPC) elicited by solutions were sensitive to the correctness of the presented answers within operations and differed across operations only for incorrect solutions. The early negativity resembled an N270 rather than an N400. The amplitude of an N300 elicited by problem presentations also differed across operations. Our results indicate that ERPs are sensitive to differences in processing across arithmetic operations in an answer verification task both during presentation of the problems, when production/retrieval processes occur, and during comparison of incorrect presented solutions with expected solutions. [ABSTRACT FROM AUTHOR]

Memory-guided decision making is dynamic and context-dependent, even though many studies describe an enhancement of the P3 for recognized items in memory tasks ('old-new effect'). This study utilized a delay-dependent working memory task during which decision making could be optimized by focusing attention on detected changes instead of recognized similarities. Mean P3 amplitude and delta activity were analyzed from participants who classified probe stimuli as identical or modified. The P3 amplitudes were larger for modified than for identical probes, even when the probe occurred 4,000 ms after the primary stimulus. Enhanced single-trial amplitude, trial-by-trial consistency, and frontoparietal phase coherence of delta activity contributed to the larger P3 for the modified probe. Thus, context-dependent attentional resource allocation supporting memory-guided decisions might explain the enhancement of the P3 for specific probe types. [ABSTRACT FROM AUTHOR]

In his seminal paper, Donders proposed that Choice reaction time (RT) tasks differ from Go/No-go RT tasks only by the insertion of a response decision operation. We evaluated this possibility by comparing the time course of Laplacian-transformed ERPs, recorded over the primary (M1s) and supplementary motor areas (SMAs) in a Choice and in a Go/No-go task. Laplacian-transformed ERPs showed that a component that develops over the SMAs during the RT of Choice tasks vanishes in our Go/No-go task. This indicates that a process, absent in the Go/No-go task, was 'inserted' in the Choice task. The Choice versus Go/No-go manipulation also modified the motor command: the activity recorded over M1s and the delay separating EMG onset from response completion depended on the nature of the task. This indicates that, although a process was inserted in the Choice task, it was not 'purely' inserted, contrary to Donders' initial assumption. [ABSTRACT FROM AUTHOR]

Event-related brain potentials were used to examine the neural correlates of task switching directed by task cues and transition cues. Task cues signal both a change of task set and the task to implement; in contrast, transition cues signal a change of task set but do not indicate the required task. The data from two experiments revealed that the frontal P2 and reconfiguration slow wave were elicited by task and transition cues and may reflect processes associated with the change detector and task set configuration. Experiment 2 revealed that the frontal positivity and transition parietal slow wave are associated with the retrieval of the prior task set from memory. These data indicate that distinct neural processes that are related to the change detector, task set configuration, and the retrieval of a recently utilized task set from memory support task switching that is guided by task and transition cues. [ABSTRACT FROM AUTHOR]

In task-switching paradigms, reaction time (RT) switch cost is eliminated on trials after a no-go trial (no-go/go sequence effect). We examined the locus of no-go interference on task-switching performance by comparing the event-related potential (ERP) time course of go/go and no-go/go sequences from cue onset to response execution. We also examined whether noninformative trials (i.e., delayed reconfiguration, no response inhibition) produce similar sequence effects. Participants switched using informative and noninformative cues ( Experiment 2 ) intermixed with no-go trials ( Experiment 1 ). Repeat RT was slower for both no-go/informative (pNG/I) and noninformative/informative (pNI/I) than informative/informative sequences. ERPs linked to anticipatory preparation showed no effect of trial sequence. ERPs indicated that pNG/I sequences reduce response readiness whereas pNI/I sequences reduce repetition benefit for repeat trials. Implications for task-switching models are discussed. [ABSTRACT FROM AUTHOR]

The error (-related) negativity (Ne or ERN) has been related to detecting the mismatch between incorrectly executed and appropriate responses or, alternatively, to the degree of conflict between different response alternatives. In this study different levels of response conflict were generated by manipulating task difficulty in a Simon task. According to the product of incorrect and subsequent correct EMG activation, the amount of conflict in error trials was indeed larger for the easy than for the hard condition. In contrast, Ne/ERN amplitudes did not differ between difficulty conditions, nor was the amount of conflict mirrored by Ne/ERN amplitude. Therefore, the present data are at variance with the hypothesis that the Ne/ERN reflects the degree of response conflict. [ABSTRACT FROM AUTHOR]

A task set may need to be inhibited to facilitate the switch to another task. This event-related potential (ERP) study determined (1) whether backward inhibition (BI) is exerted preferentially in high interference environments, and (2) whether ERPs locked to critical time points reflect BI during cue preparation and/or response stages. High interference (HI) and low interference (LI) were created by manipulating task difficulty. A reaction time (RT) BI effect (i.e., BI>control trials) was shown only during HI tasks. Cue-locked ERPs on LI tasks suggest increased attentional resources were allocated during the reactivation of a recently inhibited task. For HI tasks, BI versus control trial differences were reflected in a response-locked ERP negativity only after response selection (indexed by the response-locked lateralized readiness potential), indicating that BI is a lateral inhibition mechanism exerted during response preparation. [ABSTRACT FROM AUTHOR]

We have recently provided evidence that an error-related negativity (ERN), an ERP component generated within medial-frontal cortex, is elicited by errors made during the performance of a continuous tracking task (O.E. Krigolson & C.B. Holroyd, 2006). In the present study we conducted two experiments to investigate the ability of the medial-frontal error system to evaluate predictive error information. In two experiments participants used a joystick to perform a computer-based continuous tracking task in which some tracking errors were inevitable. In both experiments, half of these errors were preceded by a predictive cue. The results of both experiments indicated that an ERN-like waveform was elicited by tracking errors. Furthermore, in both experiments the predicted error waveforms had an earlier peak latency than the unpredicted error waveforms. These results demonstrate that the medial-frontal error system can evaluate predictive error information. [ABSTRACT FROM AUTHOR]

To elucidate the nature of the processing of visual stimulus changes, ERPs were recorded while 12 participants performed an S1–S2 matching task with multifeature stimuli. Each trial consisted of two sequentially presented stimuli (S1–S2), where S2 was either the same as S1, different from S1 only in color, different only in shape, or different in both color and shape. The four trial types were presented in random order with equal probability, and participants responded to one of these types in separate blocks. Relative to the no-change stimuli, the change stimuli elicited posterior positivity with different topography according to changing features ranging from 100 to 180 ms in all tasks. The amplitude and topography of the positivity in response to the both changes were the respective sums of those to changes in the corresponding single features. These results suggest that a feature-specific change detection system exists in the human visual system. [ABSTRACT FROM AUTHOR]

We examined age differences in event-related potentials (ERPs) associated with attentional control of task-set selection and response interference by means of a cue-based switching paradigm in which participants performed the color or word Stroop task. The results of ERPs in the cue interval indicated that P3 latencies were slowed for older adults, suggesting age-related slowing in updating currently relevant task sets. Older adults also showed a larger CNV under switching than nonswitching conditions, indicating age differences in maintaining task sets over longer periods of time. The results of target-locked ERPs revealed a negativity to incompatible Stroop trials (Ni) that was prolonged for older adults, suggesting age differences in early conflict processing. Response-locked ERPs showed a negative deflection to incompatible Stroop trials (CRN) only for younger adults, suggesting age differences also in response-related conflict processing. [ABSTRACT FROM AUTHOR]

We ran two experiments to investigate whether peripheral arterial tone reflects changes in mental effort. Finger pulse wave amplitude, interpulse interval, and pulse variability in the mid- and high-frequency bands were recorded by means of a newly developed finger plethysmograph during both rest and cognitive performance. Using a modified version of the Sternberg memory task, we selectively manipulated either the difficulty of the task (Experiment 1) or the subjects' level of engagement in the task (Experiment 2). We found a significant difference in finger pulse wave amplitude between rest and task periods, suggesting that the measure reflects changes in sympathetic activity due to task engagement. In addition, our results suggest that reduced pulse wave amplitude, signaling vasoconstriction, occurs when subjects are investing effort. [ABSTRACT FROM AUTHOR]

Four experiments investigated the attentional modulation of acoustic blinks during continuous spatial tracking tasks. Experiment 1 found blink magnitude inhibition in a visual tracking task. Experiment 2 replicated this finding and also found blink latency slowing. Experiment 3 varied the difficulty of the task and found larger blink inhibition in the easy condition. Blink latency slowing did not differ and was significant at both difficulty levels. Experiment 4 employed less difficult visual and acoustic tracking tasks at two levels of task load. Blink magnitude inhibition during the visual and facilitation during the acoustic task was significant during high load in both modality groups. Blink latency was slowed in all visual task conditions and shortened in the difficult acoustic task. These results indicate that attentional blink modulation in a continuous spatial tracking task is modality specific. [ABSTRACT FROM AUTHOR]

It was hypothesized that mental tasks that involve program running (RUN tasks) would cause a greater tonic heart rate (HR) increase than tasks that require the search for problem solutions (EDIT tasks). Three experiments using verbal, numeric, and graphic material were run to compare tasks matched for difficulty but differing in qualitative demands (RUN vs. EDIT tasks). As predicted, filling in missing letters in words caused a larger HR increase than finding words that were logical continuations of a series of words (Experiment 1) and performing arithmetic operations caused a greater HR increase than logical completion of a series of digits (Experiment 2). In Experiment 3, two of three tasks that demanded counting of graphic elements caused a larger HR increase than a task that required logical completion of a series of graphic elements. Experiments 1 and 2 also showed that RUN tasks evoked greater phasic HR acceleration than EDIT tasks. [ABSTRACT FROM AUTHOR]

The effects of the sensory modality of the lead stimulus and of task difficulty on attentional modulation of the electrical and acoustic blink reflex were examined. Participants performed a discrimination and counting task with either two acoustic, two visual, or two tactile lead stimuli. In Experiment 1, facilitation of the electrically elicited blink was greater during task-relevant than during task-irrelevant lead stimuli. Increasing task difficulty enhanced magnitude facilitation for acoustic lead stimuli. In Experiment 2, acoustic blink facilitation was greater during task-relevant lead stimuli, but was unaffected by task difficulty. Experiment 3 showed that a further increase in task difficulty did not affect acoustic blink facilitation during visual lead stimuli. The observation that blink reflexes are facilitated by attention in the present task domain is consistent across a range of stimulus modality and task difficulty conditions. [ABSTRACT FROM AUTHOR]

The present study focused on the effects of, and the interactions between, practice and task structure on human performance. The development of automatic processing through consistent stimulus-response mapping (CM) was assessed by means of measures of reaction time and event-related brain potentials. The subjects performed a visual search task in which they responded by pressing a button whenever a probe matched a memory set item. The variables manipulated in the study included the number of memory set items (1 or 4), the task structure (CM or VM), and the probability of occurrence of a memory set item (.2 or .8). Set size had a significant effect on RT in both CM and VM conditions prior to practice and in the VM condition following extensive practice. P300 latency mirrored RT, suggesting that the development of automatic processing substantially reduced stimulus evaluation time. The commonly observed relationship between probability and P300 amplitude, with larger P300s elicited by infrequent events, was found in the VM conditions but not in the CM condition after practice. Two different negative components were affected by stimulus mismatch. The N200 component behaved in a similar manner during automatic and controlled processing. However, a late frontally negative component was sensitive to the degree of mismatch only during controlled processing. [ABSTRACT FROM AUTHOR]

Visual evoked potentials were recorded from each hemisphere of both male and female subjects at a parietal and a central site while concurrent spatial or verbal mental tasks were performed. The data were analyzed by means of an automated procedure for peak identification and each component's latency and amplitude was submitted to analysis of variance. No convincing task-hemisphere interactions were found, although several components, particularly the later ones, showed either task or hemisphere related effects. At both sites, females showed greater amplitude of the N2 component for both hemispheres and both cognitive tasks. Sex differences also emerged on components P6 and N6 which were consistent with the idea that females show differential hemisphere involvement in spatial tasks. [ABSTRACT FROM AUTHOR]

The influence of task complexity upon the relationship between electrodermal activity and reaction time was studied. Subjects performed either a simple or complex fixed foreperiod reaction time task. Various measures of skin resistance were taken before and during performance of the task. Only on the more complex task were electrodermal measures related to reaction time. However, the sign of the relationship was opposite to that found in other investigations; subjects with many spontaneous fluctuations and orienting responses reacted slowly. The results were interpreted in terms of the influence of both task complexity and foreperiod characteristics. [ABSTRACT FROM AUTHOR]

Both pay out for all the trials (pay‐all) and pay out for only one randomly selected trial (pay‐one), are widely used in economics experiments to elicit choices from study participants. However, whether pay‐all and pay‐one payments modulate risk‐taking and decision‐making in the same manner remains controversial. In the present study, we used event‐related potentials (ERPs) with the Balloon Analogue Risk Task (BART) to investigate the effects of the pay‐all and pay‐one payments on dynamic sequential decision‐making behavior under uncertainty and brain activity. Behavioral data showed an increased uncertainty aversion, especially after negative feedback (balloon explosion) during the BART in the pay‐all condition, as compared to those in the pay‐one condition. The ERP data demonstrated a larger feedback‐related negativity (FRN) in response to the balloons that exploded during decision‐making in the pay‐all condition, as compared to those in the pay‐one condition. In addition, in the pay‐all condition, the FRN amplitude elicited by the explosion of the balloon correlated with the future decision‐making behavior, although this correlation was not observed in the pay‐one condition. In contrast, the P300 component was unresponsive to payment method manipulation. These findings demonstrate the differential effects of the pay‐all versus the pay‐one payments on decision‐making behavior under uncertainty and brain activity, suggesting that the payment method plays an important role in dynamic decision‐making studies. Monetary reward is widely used in experimental studies. In this study, we used event‐related potentials with the Balloon Analogue Risk Task to investigate the effects of the pay‐all versus the pay‐one payments on dynamic decision‐making behavior and brain activity. To our knowledge, this is the first exploration of how payment method influences individuals' sensitivity to outcomes in a sequential decision‐making task using both behavioral and event‐related potential data. The findings demonstrate the differential effects of the pay‐all versus the pay‐one payments on decision‐making behavior and brain activity, suggesting that the payment method plays an important role in dynamic decision‐making studies. [ABSTRACT FROM AUTHOR]

Visual perception fluctuates in sync with ongoing neural oscillations in the delta, theta, and alpha frequency bands of the human EEG. Supporting the relationship between alpha and perceptual sampling, recent work has demonstrated that variations in individual alpha frequency (IAF) correlate with the ability to discriminate one from two stimuli presented briefly in the same location. Other studies have found that, after being presented with a flickering stimulus at alpha frequencies, perception of near‐threshold stimuli fluctuates for a short time at the same frequency. Motivated by previous work, we were interested in whether this alpha entrainment involves shifts in IAF. While recording EEG, we tested whether two‐flash discrimination (a behavioral correlate of IAF) can be influenced by ~1 s of rhythmic visual stimulation at two different alpha frequencies (8.3 and 12.5 Hz). Speaking against the bottom‐up malleability of IAF, we found no change in IAF during stimulation and no change in two‐flash discrimination immediately afterward. We also found synchronous activity that persisted after 12.5 Hz stimulation, which suggests that a separate source of alpha was entrained. Importantly, we replicated the correlation between IAF and two‐flash discrimination in a no‐stimulation condition, demonstrating the sensitivity of our behavioral measure. We additionally found that IAF increased during the task compared to rest, which demonstrates that IAF is influenced by top‐down factors but is not involved in entrainment. Rhythmic visual stimulation in the alpha band (8–13 Hz) induces subsequent fluctuations in visual sensitivity at the stimulation frequency. We tested the hypothesis that this alpha entrainment operates by shifting individuals' alpha frequency (IAF) and associated perceptual functions. Despite replicating a correlation between IAF and two‐flash discrimination performance, we found no systematic influence of alpha‐band flicker on performance and no evidence of flicker‐induced shifts of IAF in the EEG. We also observed IAF increases during the task compared to rest. Taken together, results suggest that IAF and associated perceptual functions can be shifted by endogenous but not exogenous factors. [ABSTRACT FROM AUTHOR]

This study compared the ERP components and behavior associated with the auditory equiprobable and classic oddball tasks, to relate the cognitive processing stages in those paradigms and continue the development of the sequential processing schema. Target and nontarget ERP data were acquired from 66 healthy young adults (Mage = 20.1, SD = 2.4 years, 14 male) who completed both equiprobable (target p = 0.5) and oddball tasks (target p = 0.3). Separate temporal PCAs were used to decompose the ERP data in each task and condition, and the similarity of the components identified in each condition was examined between tasks. Probability effects on component amplitudes and behavior were also analyzed to identify task differences in cognitive demands. A highly similar series of components was identified in each task, closely matching the schema: targets elicited N1‐3, N1‐1, PN, N2c, P3b, SW1, SW2; whereas nontargets elicited N1‐3, N1‐1, PN, N2b, P3a, SW1, SW2. N1‐1 and PN amplitudes increased as stimulus probability decreased, irrespective of the condition. N2b, P3b, SW1, and SW2 amplitudes also varied between tasks, illustrating task‐specific demands on those processing stages. These findings complemented the behavioral outcomes, which demonstrated greater accuracy and control in the classic oddball task. Overall, this study demonstrated comparable processing in the auditory equiprobable and classic oddball tasks, extending the generalizability of the schema and enabling further integration of the ERP theory associated with these tasks. This study also clarifies stimulus probability effects on the schema, providing important insight into the functionality of common ERP components. [ABSTRACT FROM AUTHOR]

Prior to and during movement, oscillatory alpha activity gates cognitive resources toward motor areas of the cortex by inhibiting neuronal excitability in nonmotor areas. The present study examined the effect of manipulating target variability on this alpha gating phenomenon. Using a baseline‐test‐retention design, we measured EEG alpha power, performance accuracy, and task difficulty in 32 recreational golfers as they putted golf balls (20 per target) to one central target (baseline, retention) and four targets of different directions and extents (manipulation). For participants in the random group (n = 16), target location varied with each repetition in a random fashion, whereas for participants in the blocked group (n = 16), it was kept constant within blocks. Regional analyses revealed a focal pattern of lower central alpha and higher occipital and temporal alpha. This topography was specific to preparation for movement and was associated with performance: smallest performance errors were preceded by decreased central combined with increased occipital alpha. The random group performed worse than the blocked group and found the task more difficult. Importantly, left temporal alpha prior to movement onset was lower for the random group than the blocked group. No group differences were found at baseline or retention. Our study proved that alpha gating can be altered by manipulating intertrial variability and thereby demonstrated the utility of the alpha gating model. Our findings underscore the importance of inhibiting occipital and left temporal areas when performing movements and provide further evidence that alpha gating reflects neural efficiency during motor tasks. [ABSTRACT FROM AUTHOR]

The Bereitschaftspotential (BP) and the P3 are well‐known ERPs usually observed during self‐paced and externally triggered tasks. Recently, the BP was also detected in externally triggered tasks before stimulus onset. However, doubts have been raised about the authenticity of the BP in these tasks due to possible overlaps with the previous trial P3 (hereinafter s‐1 P3). Here, we aim to test the authenticity of the BP in externally triggered tasks by comparing ERPs obtained during two visuomotor response tasks with different interstimulus intervals (ISIs) allowing (short‐ISI; 1,000–2,000 ms) or not (long‐ISI; 2,000–4,000 ms) P3‐BP overlaps. In line with previous research, we hypothesize that BP and the s‐1 P3 contribute independently to the scalp‐detected activities during these tasks. ERPs were recorded from 14 healthy participants during the short‐ISI and long‐ISI visuomotor response tasks. Amplitudes and latencies of pre‐ (BP and pN) and poststimulus ERP components (P1, pN1, pP1, N1, pP2, dpP2, N2, P3) were compared between conditions. No effect of ISI was found on the amplitude of any pre‐ and poststimulus components. In contrast, longer ISI is associated with earlier onsets of the BP and pN components. In visuomotor response tasks, the BP is independent from the P3 elicited by the previous trial (s‐1 P3), even using relatively short ISI. Since the different ISIs did not affect the amplitude of the BP and the P3 components, we conclude that also a short ISI can be adopted safely and conveniently to keep a reasonable duration of the overall experiment. [ABSTRACT FROM AUTHOR]