Comparative analysis of event-related potentials during Go/NoGo and CPT: decomposition of electrophysiological markers of response inhibition and sustained attention

Neuropsychological tests target specific cognitive functions; however, numerous cognitive subcomponents are involved in each test. The aim of this study was to decompose the components of two frontal executive function tests, Go/NoGo (GNG) and cued continuous performance task (CPT), by analyzing event-related potentials (ERPs) of 24 subjects both in time and time-frequency domains. In the time domain, P1, N1, P2, N2 and P3 peak amplitudes and latencies and mean amplitudes of 100 ms time windows of the post-P3 time period were measured. For GNG, the N1 amplitude and for both GNG and CPT N2 amplitudes were significantly higher in the NoGo condition compared with the Go condition. P3 had a central maximum in the NoGo conditions of both paradigms in contrast to a parietal maximum in the Go conditions. All peaks except P1 and mean amplitudes of the post-P3 period were more positive in CPT compared to those of GNG. N1, N2 and P3 latencies were longer for the NoGo condition than the Go condition in the CPT. In time-frequency analyses, the NoGo condition evoked higher theta coefficients than the Go condition, whereas the CPT and GNG paradigms differed mainly in the delta band. These results suggest that theta component reflects response inhibition in both GNG and CPT, whereas delta component reflects the more demanding sustained attention requirement of the CPT. The latency prolongation observed with the NoGo condition of the CPT paradigm was thought to be due to perseverance/inhibition conflict enhanced by the primer stimuli in CPT.     

Use of an Instrumented Timed Up and Go (iTUG) for Fall Risk Classification

Abstract

Aim: To determine if an instrumented Timed Up and Go (iTUG) can accurately classify older adult recurrent fallers and non-fallers who are age and sex-matched. Methods: iTUG data from older adult recurrent fallers (n?=?25) and age and sex-matched non-fallers (n?=?25) were selected for comparison from a pool of participants (n?=?148) that were involved in a larger age and mobility related study. Results: All of the iTUG measures demonstrated a low level of accuracy in classifying recurrent fallers from non-fallers (AUC?=?0.49–0.56) and there were no significant differences in any of the iTUG performance measures between groups. Conclusion: The iTUG was unable to appropriately classify or differentiate older adult recurrent fallers from non-fallers who were both age and sex-matched. The role and usefulness of body-worn sensors for assessing mobility and fall risk require further investigation.     

The relationship between poor sleep and inhibitory functions indicated by event-related potentials

The present study focused on the relationship between normal variations of sleep and inhibitory functions as reflected in event-related potentials. For this reason one night of 21 healthy participants was analysed. After waking up all participants completed a visual Go/Nogo task. On the basis of a sleep disturbance index (SDI) the participants were separated into 8 SDI-good and 13 SDI-poor sleepers using a cluster analysis. The results showed that Nogo-N2 amplitude was smaller and Nogo-P3 latency longer in SDI-poor sleepers. Moreover, Go-P3 amplitude was smaller in SDI-poor sleepers. Performance parameters were not influenced by poor sleep. We concluded that poor sleep specifically affects the intensity of pre-motor inhibitory processes (Nogo-N2 amplitude), the speed to inhibit a motor response (Nogo-P3 latency) and the intensity of task-relevant information processing (Go-P3 amplitude). In further studies, it should be explored under which conditions such subliminal deficits also become relevant for overt behaviour.

The Evaluation of Proof-of-Concept Trial Design for Compound Selection

ABSTRACT

Traditionally, clinical proof-of-concept (POC) trials were designed as mini-phase III trials with a lower power and/or an intermediate endpoint. And go/no-go decisions were made based on a specification of the Type I error. This article considers a POC trial a tool to select the compound with a desired efficacy profile and introduces the approach to compute the distribution of the treatment effect given a go decision. The methodology is then applied to three POC design options that range from a direct comparison to indirect comparisons utilizing historical data. Using the tools proposed, we are able to compare the performance of the designs and impact of sample sizes with respect to the probability of meeting the target product profile given a go decision or no-go decision. Furthermore, for given a design we highlight the trade-off for the go/no-go decision and propose an approach to search for the optimal decision criterion that maximizes a utility defined by an economic scale. We illustrate the approach and results with an example for the development of a treatment for rheumatoid arthritis.     

Longitudinal associations between conflict monitoring and emergent academic skills: An event-related potentials study

Identifying the links between specific cognitive functions and emergent academic skills can help determine pathways to support both early academic performance and later academic achievement. Here, we investigated the longitudinal associations between a key aspect of cognitive control, conflict monitoring, and emergent academic skills from preschool through first grade, in a large sample of socioeconomically diverse children (N = 261). We recorded event-related potentials (ERPs) during a Go/No-Go task. The neural index of conflict monitoring, ΔN2, was defined as larger N2 mean amplitudes for No-Go versus Go trials. ΔN2 was observed over the right hemisphere across time points and showed developmental stability. Cross-lagged panel models revealed prospective links from ΔN2 to later math performance, but not reading performance. Specifically, larger ΔN2 at preschool predicted higher kindergarten math performance, and larger ΔN2 at kindergarten predicted higher first-grade math performance, above and beyond the behavioral performance in the Go/No-Go task. Early academic skills did not predict later ΔN2. These findings provided electrophysiological evidence for the contribution of conflict monitoring abilities to emergent math skills. In addition, our findings suggested that neural indices of cognitive control can provide additional information in predicting emergent math skills, above and beyond behavioral task performance.     

内隐职业刻板印象及其信息加工机制的研究

目的 探讨内隐职业刻板印象、内隐职业偏爱及其加工机制,更好地指导大学生和在职人员的职业选择和发展.方法 内隐联想测验和纸笔版反应与不反应联想任务.结果 ①性别主效应不显著(F-0.649,P=0.424),任务主效应显著(F=1141.930,P=0.000),性别和任务的交互作用不显著(F=0.109,P=0.743...     

Conflict and inhibition in the cued-Go/NoGo task

Objective

Current debate centres on the inhibitory and conflict interpretations of the N2 and P3 components of the event-related potential (ERP). We examined behavioural responses and ERPs in a cued-Go/NoGo task.

Methods

Participants were required to inhibit a planned response (NoGo target after Go cue), change a planned response to a different one (Invalid cueing), and activate an unexpected response (Go target after NoGo cue).

Results

Responses were slower when participants had to change a planned response, and execute an unplanned response. N2 was more negative whenever the presented target required a different response to what was expected based on the cue. In contrast, P3 was increased when participants had to change or inhibit a planned response, but not when executing a response where none was planned.

Conclusions

N2 results lend support to the conflict account, while P3 reflects cancellation of a planned response.

Significance

This paper provides the first test of conflict involving activation of an unplanned response in a cued-Go/NoGo task.