Comparison of Common Amplitude Metrics in Event-Related Potential Analysis

Abstract

Waveform data resulting from time-intensive longitudinal designs require careful treatment. In particular, the statistical properties of summary metrics in this area are crucial. We draw on event-related potential (ERP) studies, a field with a relatively long history of collecting and analyzing such data, to illustrate our points. In particular, three summary measures for a component in the average ERP waveform feature prominently in the literature: the maximum (or peak amplitude), the average (or mean amplitude) and a combination (or adaptive mean). We discuss the methodological divide associated with these summary measures. Through both analytic work and simulation study, we explore the properties (e.g., Type I and Type II errors) of these competing metrics for assessing the amplitude of an ERP component across experimental conditions. The theoretical and simulation-based arguments in this article illustrate how design (e.g., number of trials per condition) and analytic (e.g., window location) choices affect the behavior of these amplitude summary measures in statistical tests and highlight the need for transparency in reporting the analytic steps taken. There is an increased need for analytic tools for waveform data. As new analytic methods are developed to address these time-intensive longitudinal data, careful treatment of the statistical properties of summary metrics used for null hypothesis testing is crucial.     

Do 5- and 6-Year-Old Children Attempt to Appear Fair to Others?

Abstract

Children come to prefer fair distributions at the age of 5 to 6?years. But do they actually want to be fair, or do they want to appear fair to others? In three conditions, an experimenter initially distributed chocolates to 5-/6-year-old participants and partners they were paired with. Participants always possessed, through some means, two chocolates when the experimenter returned after a brief absence, and they had to decide whether to take an extra one for themselves. To measure the extent to which children were concerned with actually being fair versus appearing fair, two conditions were created in which children were led to believe that the experimenter did not know that the distributions had become equal. In the windfall condition, a confederate gave one additional chocolate to the participant, and in the partner condition, the partner transferred one chocolate to the participant. Compared to the control condition, participants who passed the false belief task in both of these conditions tried to appear fair in their distribution. Thus 5-/6-year-old children seem to prefer appearing fair to others regardless of the situation.     

Aggregate temperament scores from multiple countries: Associations with aggregate personality traits,cultural dimensions,and allelic frequency

Aggregate temperament scores were calculated across 17 studies for 18 countries. These scores were analyzed in relation to aggregate personality scores, cultural orientation, and allelic distribution reported in prior studies. Cross-culture patterns were largely consistent with those previously reported for personality: countries high on Surgency (SUR) were high on Extraversion, high Negative Affectivity (NEG) was consistent with Neuroticism, and Regulatory Capacity (RC) with Agreeableness. Regarding cultural orientation, aggregate SUR was associated with low Power Distance and Long-Term Orientation; NEG with low Individualism and high Masculinity and Uncertainty Avoidance; and RC with low Power Distance and Masculinity. Higher proportion of MAOA-uVNTR low expression alleles was associated with low SUR and low RC; and A118G G-form allele proportion with low RC.     

The conscious experience of color constancy and neural responses to subliminal deviations – A behavioral and EEG/ERP oddball study

IntroductionColor constancy, a property of conscious color experience, maintains object color appearance across illuminant changes. We investigated the neural correlates of subliminal vs. conscious stimulus deviations of color constancy manipulations.MethodsBehavioral and Oddball EEG/ERP experiments were conducted (n = 20). Psychophysical illuminant variation discrimination thresholds were first estimated, to establish individual perceptual awareness ranges, allowing for simulation of natural daylight spectral and spatial variations on colored surfaces, at different ambiguity levels.ResultsBehavioral results validated illuminant choice. ERPs showed a significant modulation of posterior P1 component specifically for the subliminal global uniform deviation condition, respecting color constancy. Neural correlates of conscious percepts were identified at posterior N2-P3 latencies, parietal (P3b) and frontal regions.ConclusionsWe identified an early subliminal correlate of low-level illuminant change, which reflects automatic unconscious detection of global color constancy deviations. Its suppression under conscious perception is probably due to top-down suppression according to prediction error models.     

Designing and evaluating an intelligent augmented reality system for assisting older adults’ medication management

Intelligent Assistive Systems (IASs) provide personalised support to individuals to increase their autonomy and competence in performing activities. The personalisation of such technology represents a particular challenge, for the individuals abilities typically change over time. The aim of this research was to explore a theory-based, activity-centred framework for the development of IASs that both facilitate the active involvement of caregivers and target users and allow for adaptation to the individual over time.Medication management was focused on as a case study. Three older adults and two caregivers were involved in a co-design process of an IAS prototype system, the MED-AR, which uses projection-based augmented reality as the user interface technology. The theoretical framework for the design and evaluation of the MED-AR was activity theory. For the decision-making process of the MED-AR, formal argumentation theory was used. The major contributions of the study are (i) a formal framework for understanding the level of independence in activities and the way an IAS can tailor support to an individual and a situation, including caregivers; and (ii) a model for involving older adults and caregivers in a co-design process in the first phases of developing IASs.     

Modeling duration of overtaking in two lane highways

The paper attempts to reveal which factors may influence the duration of overtaking in two lane highways. Questions such as what is the duration of young male and female drivers’ overtaking activities and, given that a driver conducts an overtaking maneuver, how long will it take, are addressed using classical survival analysis. Data are collected using a driving simulator. Different models are developed for describing the total overtaking duration, as well as the duration of the acceleration and back-to-lane phases. Results show that the duration of each of the phases of overtaking considered, as well as the total overtaking duration may be best described by a Log–logistic distribution. Analyses point out that, apart from the acceleration phase, the gender is a critical factor to the duration modeling. Other influential factors are the speed difference from the lead vehicle, the speed of opposing traffic, the spacing from the lead and opposing traffic, as well as whether the driver is engaged in multiple overtakes. Finally, the modeling implications to driving assistance systems are discussed.