Bayesian inference for psychology. Part II: Example applications with JASP

Bayesian hypothesis testing presents an attractive alternative to p value hypothesis testing. Part I of this series outlined several advantages of Bayesian hypothesis testing, including the ability to quantify evidence and the ability to monitor and update this evidence as data come in, without the need to know the intention with which the data were collected. Despite these and other practical advantages, Bayesian hypothesis tests are still reported relatively rarely. An important impediment to the widespread adoption of Bayesian tests is arguably the lack of user-friendly software for the run-of-the-mill statistical problems that confront psychologists for the analysis of almost every experiment: the t-test, ANOVA, correlation, regression, and contingency tables. In Part II of this series we introduce JASP (http://www.jasp-stats.org), an open-source, cross-platform, user-friendly graphical software package that allows users to carry out Bayesian hypothesis tests for standard statistical problems. JASP is based in part on the Bayesian analyses implemented in Morey and Rouder’s BayesFactor package for R. Armed with JASP, the practical advantages of Bayesian hypothesis testing are only a mouse click away.     

Mindfulness Based Flourishing Program: A Cross-Cultural Study of Hong Kong Chinese and British Participants

The Mindfulness Based Flourishing Program (MBFP) is an online 8-week intervention developed for enhancing wellbeing with the use of mindfulness practices, through targeting a range of positive variables. The efficacy of the MBFP has been demonstrated in a randomized controlled trial, and in order to further establish it as an intervention with widespread application, cross-cultural validation is warranted. The current study was conducted with the primary aim of testing the validity of the MBFP with a Hong Kong Chinese population, as well as verifying its positive effects. A randomized wait-list controlled design was adopted with 115 participants (92 females, mean age = 31.50). Intervention outcomes were compared between Hong Kong Chinese and British participants. Five positive variables were examined (self-compassion, meaning in life, positive and negative emotions, gratitude, and mindfulness), and measures were taken pre- and post-intervention. Significant gains in wellbeing measures were observed in both the Hong Kong Chinese and the British experimental groups. Levels of wellbeing post-intervention were also higher for the two experimental groups as compared to their control counterparts. The current study provides preliminary evidence for the MBFP’s cross-cultural validity, and strengthens previous claims for its efficacy as a new, accessible alternative for enhancing wellbeing.     

What to expect from your remote eye-tracker when participants are unrestrained

The marketing materials of remote eye-trackers suggest that data quality is invariant to the position and orientation of the participant as long as the eyes of the participant are within the eye-tracker’s headbox, the area where tracking is possible. As such, remote eye-trackers are marketed as allowing the reliable recording of gaze from participant groups that cannot be restrained, such as infants, schoolchildren and patients with muscular or brain disorders. Practical experience and previous research, however, tells us that eye-tracking data quality, e.g. the accuracy of the recorded gaze position and the amount of data loss, deteriorates (compared to well-trained participants in chinrests) when the participant is unrestrained and assumes a non-optimal pose in front of the eye-tracker. How then can researchers working with unrestrained participants choose an eye-tracker? Here we investigated the performance of five popular remote eye-trackers from EyeTribe, SMI, SR Research, and Tobii in a series of tasks where participants took on non-optimal poses. We report that the tested systems varied in the amount of data loss and systematic offsets observed during our tasks. The EyeLink and EyeTribe in particular had large problems. Furthermore, the Tobii eye-trackers reported data for two eyes when only one eye was visible to the eye-tracker. This study provides practical insight into how popular remote eye-trackers perform when recording from unrestrained participants. It furthermore provides a testing method for evaluating whether a tracker is suitable for studying a certain target population, and that manufacturers can use during the development of new eye-trackers.     

Rise time and formant transition duration in the discrimination of speech sounds: the Ba-Wa distinction in developmental dyslexia

Across languages, children with developmental dyslexia have a specific difficulty with the neural representation of the sound structure (phonological structure) of speech. One likely cause of their difficulties with phonology is a perceptual difficulty in auditory temporal processing (Tallal, 1980). Tallal (1980) proposed that basic auditory processing of brief, rapidly successive acoustic changes is compromised in dyslexia, thereby affecting phonetic discrimination (e.g. discriminating /b/ from /d/) via impaired discrimination of formant transitions (rapid acoustic changes in frequency and intensity). However, an alternative auditory temporal hypothesis is that the basic auditory processing of the slower amplitude modulation cues in speech is compromised (Goswami et al., 2002). Here, we contrast children's perception of a synthetic speech contrast (ba/wa) when it is based on the speed of the rate of change of frequency information (formant transition duration) versus the speed of the rate of change of amplitude modulation (rise time). We show that children with dyslexia have excellent phonetic discrimination based on formant transition duration, but poor phonetic discrimination based on envelope cues. The results explain why phonetic discrimination may be allophonic in developmental dyslexia (Serniclaes et al., 2004), and suggest new avenues for the remediation of developmental dyslexia.     

Saved by the blush: being trusted despite defecting

This study examined whether blushing after a sociomoral transgression remediates trustworthiness in an interdependent context. Participants (N = 196) played a computerized prisoner's dilemma game with a virtual opponent who defected in the second round of the game. After the defection, a photograph of the opponent was shown, displaying a blushing or a nonblushing face. In a subsequent Trust Task, the blushing opponent was entrusted with more money than the nonblushing opponent. In further support of the alleged remedial properties of the blush, participants also indicated that they trusted the blushing opponent more, expected a lower probability that she would defect again, and judged the blushing opponent more positively.     

The effect of foregone outcomes on choices from experience

We examined the relative weight given to obtained and foregone outcomes (i.e., outcomes from the non-chosen options) in repeated choices using cognitive modeling. Previous modeling studies have yielded mixed results. When participants' choices are analyzed by models that predict the next choice ahead in a sequence of decisions, the results imply that people give less weight to foregone than to obtained outcomes. In contrast, in simulation models of n trials ahead, the results imply that, on average, people give equal weight to foregone and obtained outcomes. Using datasets of experience-based binary choices with fixed (stationary) payoff distributions (Erev & Haruvy, in press) and dynamic (nonstationary) payoff distributions (Rakow & Miler, 2009), we employed generalization tests at the individual level to examine whether the findings derived from the one-step-ahead method are due to overfitting. The results of trial-ahead model fitting implied that for the nonstationary tasks only, foregone outcomes received lower weight. However, when this dataset was assessed via generalization criteria at the individual level, equal weighting of foregone and obtained outcomes was the best assumption. This implies that overfitting is implicated in the superior fit of models that assume discounting of foregone outcomes.     

Nostalgia as a Resource for Psychological Health and Well‐Being

Historically, nostalgia has been viewed as a disease of the brain or the mind. However, in recent years, nostalgia has received a conceptual rehabilitation due to a revival of scholarly interest accompanied by the use of contemporary empirical methods. Drawing upon this recent work, we propose that nostalgia is an important resource for psychological health and well‐being. We begin by detailing the characteristics of the nostalgic experience and then discuss a wide range of studies demonstrating that psychological threat triggers nostalgia, nostalgia enhances psychological health and well‐being, and nostalgia promotes adaptive psychological functioning among individuals at risk for poor mental health. We also highlight the need for future research on nostalgia's relation to psychological health.     

Answering to Future People: Responsibility for Climate Change in a Breaking World

Our everyday notions of responsibility are often driven by our need to justify ourselves to specific others – especially those we harm, wrong, or otherwise affect. One challenge for contemporary ethics is to extend this interpersonal urgency to our relations with those future people who are harmed or affected by our actions. In this article, I explore our responsibility for climate change by imagining a possible ‘broken future’, damaged by the carbon emissions of previous generations (including ourselves), and then asking what its inhabitants might think of our current behaviour, our moral thinking, and our excuses. In particular, I will focus on a simplified scenario where present people can only avoid a broken future by sacrificing Rawlsian favourable conditions. Suppose we refuse to avoid a broken future, on the grounds that we cannot be expected to make such great sacrifices. If the broken future lacks favourable conditions, will its inhabitants accept our excuses? Will they hold us responsible for things we regard as excusable? If so, should we be guided by their judgements or by our own?     

Child,parent, and peer predictors of early-onset substance use: a multisite longitudinal study

The purpose of this study was to identify kindergarten-age predictors of early-onset substance use from demographic, environmental, parenting, child psychological, behavioral, and social functioning domains. Data from a longitudinal study of 295 children were gathered using multiple-assessment methods and multiple informants in kindergarten and 1st grade. Annual assessments at ages 10, 11, and 12 reflected that 21% of children reported having initiated substance use by age 12. Results from longitudinal logistic regression models indicated that risk factors at kindergarten include being male, having a parent who abused substances, lower levels of parental verbal reasoning, higher levels of overactivity, more thought problems, and more social problem solving skills deficits. Children with no risk factors had less than a 10% chance of initiating substance use by age 12, whereas children with 2 or more risk factors had greater than a 50% chance of initiating substance use. Implications for typology, etiology, and prevention are discussed.