Smartphone sensor accuracy varies from device to device in mobile research: The case of spatial orientation.

Smartphone usage is increasing around the globe-in daily life and as a research device in behavioral science. Smartphones offer the possibility to gather longitudinal data at little cost to researchers and participants. They provide the option to verify self-report data with data from sensors built into most smartphones. How accurate this sensor data is when gathered via different smartphone devices, e.g., in a typical experience sampling framework, has not been investigated systematically. With the present study, we investigated the accuracy of orientation data about the spatial position of smartphones via a newly invented measurement device, the RollPitcher. Objective status of pitch (vertical orientation) and roll (horizontal orientation) of the smartphone was compared to data gathered from the sensors via web browsers and native apps. Bayesian ANOVAs confirmed that the deviations in pitch and roll differed between smartphone models, with mean inaccuracies per device of up to 2.1° and 6.6°, respectively. The inaccuracies for measurements of roll were higher than for pitch, d = .28, p < .001. Our results confirm the presence of heterogeneities when gathering orientation data from different smartphone devices. In most cases, measurement via a web browser was identical to measurement via a native app, but this was not true for all smartphone devices. As a solution to lack of sensor accuracy, we recommend the development and implementation of a coherent research framework and also discuss the implications of the heterogeneities in orientation data for different research designs.

Content and source analysis of popular tweets following a recent case of diphtheria in Spain.

Background: Despite major progress in global vaccination coverage, immunization rates are falling, resulting in outbreaks of vaccine-preventable diseases. This study analyses content and source of the most popular tweets related to a recent case in Spain where an unvaccinated child contracted and later died from diphtheria. Understanding the characteristics of these tweets in the context of vaccination could inform efforts by health promotion professionals to increase their reach and impact. Methods: We extracted tweets containing keywords related to the diphtheria case (from 1 May to 15 July 2015). We explored the prevalence of terms relating to policy and misinformation and manually coded the 194 most popular tweets (retweeted 100 or more times) with regard to source, topic, tone and sentiment. Results: A total of 722 974 tweets were collected. Prevalence of terms relating to policy and misinformation increased at the onset of the case and after the death of the child. Popular tweets (194) were either pro-vaccination (58%) or neutral, with none classified as anti-vaccination. Popular topics included criticism towards anti-vaccination groups (35%) and effectiveness of immunization (22%). Popular tweets were informative (47%) or opinions (53%), which mainly expressed frustration (24%) or humour/sarcasm (23%). Popular Twitter accounts were newspaper and TV channels (15%), as well as individual journalists and authors of popular science (13.4%). Conclusions: Healthcare organizations could collaborate with popular journalists or news outlets and employ authors of popular science to disseminate health information on social media, while addressing public concerns and misinformation in accessible ways.

Best practices: Two Web-browser-based methods for stimulus presentation in behavioral experiments with high-resolution timing requirements.

The Web is a prominent platform for behavioral experiments, for many reasons (relative simplicity, ubiquity, and accessibility, among others). Over the last few years, many behavioral and social scientists have conducted Internet-based experiments using standard web technologies, both in native JavaScript and using research-oriented frameworks. At the same time, vendors of widely used web browsers have been working hard to improve the performance of their software. However, the goals of browser vendors do not always coincide with behavioral researchers' needs. Whereas vendors want high-performance browsers to respond almost instantly and to trade off accuracy for speed, researchers have the opposite trade-off goal, wanting their browser-based experiments to exactly match the experimental design and procedure. In this article, we review and test some of the best practices suggested by web-browser vendors, based on the features provided by new web standards, in order to optimize animations for browser-based behavioral experiments with high-resolution timing requirements. Using specialized hardware, we conducted four studies to determine the accuracy and precision of two different methods. The results using CSS animations in web browsers (Method 1) with GPU acceleration turned off showed biases that depend on the combination of browser and operating system. The results of tests on the latest versions of GPU-accelerated web browsers showed no frame loss in CSS animations. The same happened in many, but not all, of the tests conducted using requestAnimationFrame (Method 2) instead of CSS animations. Unbeknownst to many researchers, vendors of web browsers implement complex technologies that result in reduced quality of timing. Therefore, behavioral researchers interested in timing-dependent procedures should be cautious when developing browser-based experiments and should test the accuracy and precision of the whole experimental setup (web application, web browser, operating system, and hardware).

Learning to infer the time of our actions and decisions from their consequences.

Research shows that people infer the time of their actions and decisions from their consequences. We asked how people know how much time to subtract from consequences in order to infer their actions and decisions. They could either subtract a fixed, default, time from consequences, or learn from experience how much time to subtract in each situation. In two experiments, participants' actions were followed by a tone, which was presented either immediately or after a delay. In Experiment 1, participants estimated the time of their actions; in Experiment 2, the time of their decisions to act. Both actions and decisions were judged to occur sooner or later as a function of whether consequences were immediate or delayed. Estimations tended to be shifted toward their consequences, but in some cases they were shifted away from them. Most importantly, in all cases participants learned progressively to adjust their estimations with experience.

Metronome LKM: An open source virtual keyboard driver to measure experiment software latencies.

Experiment software is often used to measure reaction times gathered with keyboards or other input devices. In previous studies, the accuracy and precision of time stamps has been assessed through several means: (a) generating accurate square wave signals from an external device connected to the parallel port of the computer running the experiment software, (b) triggering the typematic repeat feature of some keyboards to get an evenly separated series of keypress events, or (c) using a solenoid handled by a microcontroller to press the input device (keyboard, mouse button, touch screen) that will be used in the experimental setup. Despite the advantages of these approaches in some contexts, none of them can isolate the measurement error caused by the experiment software itself. Metronome LKM provides a virtual keyboard to assess an experiment's software. Using this open source driver, researchers can generate keypress events using high-resolution timers and compare the time stamps collected by the experiment software with those gathered by Metronome LKM (with nanosecond resolution). Our software is highly configurable (in terms of keys pressed, intervals, SysRq activation) and runs on 2.6-4.8 Linux kernels.

Neuromyths in Education: Prevalence among Spanish Teachers and an Exploration of Cross-Cultural Variation.

Enthusiasm for research on the brain and its application in education is growing among teachers. However, a lack of sufficient knowledge, poor communication between educators and scientists, and the effective marketing of dubious educational products has led to the proliferation of numerous 'neuromyths.' As a first step toward designing effective interventions to correct these misconceptions, previous studies have explored the prevalence of neuromyths in different countries. In the present study we extend this applied research by gathering data from a new sample of Spanish teachers and by meta-analyzing all the evidence available so far. Our results show that some of the most popular neuromyths identified in previous studies are also endorsed by Spanish teachers. The meta-analytic synthesis of these data and previous research confirms that the popularity of some neuromyths is remarkably consistent across countries, although we also note peculiarities and exceptions with important implications for the development of effective interventions. In light of the increasing popularity of pseudoscientific practices in schools worldwide, we suggest a set of interventions to address misconceptions about the brain and education.

A HTML5 open source tool to conduct studies based on Libet's clock paradigm.

Libet's clock is a well-known procedure in experiments in psychology and neuroscience. Examples of its use include experiments exploring the subjective sense of agency, action-effect binding, and subjective timing of conscious decisions and perceptions. However, the technical details of the apparatus used to conduct these types of experiments are complex, and are rarely explained in sufficient detail as to guarantee an exact replication of the procedure. With this in mind, we developed Labclock Web, a web tool designed to conduct online and offline experiments using Libet's clock. After describing its technical features, we explain how to configure specific experiments using this tool. Its degree of accuracy and precision in the presentation of stimuli has been technically validated, including the use of two cognitive experiments conducted with voluntary participants who performed the experiment both in our laboratory and via the Internet. Labclock Web is distributed without charge under a free software license (GPLv3) since one of our main objectives is to facilitate the replication of experiments and hence the advancement of knowledge in this area.

The effect of noise-induced variance on parameter recovery from reaction times.

BACKGROUND: Technical noise can compromise the precision and accuracy of the reaction times collected in psychological experiments, especially in the case of Internet-based studies. Although this noise seems to have only a small impact on traditional statistical analyses, its effects on model fit to reaction-time distributions remains unexplored. RESULTS: Across four simulations we study the impact of technical noise on parameter recovery from data generated from an ex-Gaussian distribution and from a Ratcliff Diffusion Model. Our results suggest that the impact of noise-induced variance tends to be limited to specific parameters and conditions. CONCLUSIONS: Although we encourage researchers to adopt all measures to reduce the impact of noise on reaction-time experiments, we conclude that the typical amount of noise-induced variance found in these experiments does not pose substantial problems for statistical analyses based on model fitting.

Visual DMDX: A web-based authoring tool for DMDX, a Windows display program with millisecond accuracy.

DMDX is a software package for the experimental control and timing of stimulus display for Microsoft Windows systems. DMDX is reliable, flexible, millisecond accurate, and can be downloaded free of charge; therefore it has become very popular among experimental researchers. However, setting up a DMDX-based experiment is burdensome because of its command-based interface. Further, DMDX relies on RTF files in which parts of the stimuli, design, and procedure of an experiment are defined in a complicated (DMASTR-compatible) syntax. Other experiment software, such as E-Prime, Psychopy, and WEXTOR, became successful as a result of integrated visual authoring tools. Such an intuitive interface was lacking for DMDX. We therefore created and present here Visual DMDX (http://visualdmdx.com/), a HTML5-based web interface to set up experiments and export them to DMDX item files format in RTF. Visual DMDX offers most of the features available from the rich DMDX/DMASTR syntax, and it is a useful tool to support researchers who are new to DMDX. Both old and modern versions of DMDX syntax are supported. Further, with Visual DMDX, we go beyond DMDX by having added export to JSON (a versatile web format), easy backup, and a preview option for experiments. In two examples, one experiment each on lexical decision making and affective priming, we explain in a step-by-step fashion how to create experiments using Visual DMDX. We release Visual DMDX under an open-source license to foster collaboration in its continuous improvement.

Accuracy and precision of visual stimulus timing in PsychoPy: no timing errors in standard usage.

In a recent report published in PLoS ONE, we found that the performance of PsychoPy degraded with very short timing intervals, suggesting that it might not be perfectly suitable for experiments requiring the presentation of very brief stimuli. The present study aims to provide an updated performance assessment for the most recent version of PsychoPy (v1.80) under different hardware/software conditions. Overall, the results show that PsychoPy can achieve high levels of precision and accuracy in the presentation of brief visual stimuli. Although occasional timing errors were found in very demanding benchmarking tests, there is no reason to think that they can pose any problem for standard experiments developed by researchers.

Presentation accuracy of the web revisited: animation methods in the HTML5 era.

Using the Web to run behavioural and social experiments quickly and efficiently has become increasingly popular in recent years, but there is some controversy about the suitability of using the Web for these objectives. Several studies have analysed the accuracy and precision of different web technologies in order to determine their limitations. This paper updates the extant evidence about presentation accuracy and precision of the Web and extends the study of the accuracy and precision in the presentation of multimedia stimuli to HTML5-based solutions, which were previously untested. The accuracy and precision in the presentation of visual content in classic web technologies is acceptable for use in online experiments, although some results suggest that these technologies should be used with caution in certain circumstances. Declarative animations based on CSS are the best alternative when animation intervals are above 50 milliseconds. The performance of procedural web technologies based on the HTML5 standard is similar to that of previous web technologies. These technologies are being progressively adopted by the scientific community and have promising futures, which makes their use advisable to utilizing more obsolete technologies.

Measuring software timing errors in the presentation of visual stimuli in cognitive neuroscience experiments.

Because of the features provided by an abundance of specialized experimental software packages, personal computers have become prominent and powerful tools in cognitive research. Most of these programs have mechanisms to control the precision and accuracy with which visual stimuli are presented as well as the response times. However, external factors, often related to the technology used to display the visual information, can have a noticeable impact on the actual performance and may be easily overlooked by researchers. The aim of this study is to measure the precision and accuracy of the timing mechanisms of some of the most popular software packages used in a typical laboratory scenario in order to assess whether presentation times configured by researchers do not differ from measured times more than what is expected due to the hardware limitations. Despite the apparent precision and accuracy of the results, important issues related to timing setups in the presentation of visual stimuli were found, and they should be taken into account by researchers in their experiments.

Build your own social network laboratory with Social Lab: a tool for research in social media.

Social networking has surpassed e-mail and instant messaging as the dominant form of online communication (Meeker, Devitt, & Wu, 2010). Currently, all large social networks are proprietary, making it difficult to impossible for researchers to make changes to such networks for the purpose of study design and access to user-generated data from the networks. To address this issue, the authors have developed and present Social Lab, an Internet-based free and open-source social network software system available from http://www.sociallab.es . Having full availability of navigation and communication data in Social Lab allows researchers to investigate behavior in social media on an individual and group level. Automated artificial users ("bots") are available to the researcher to simulate and stimulate social networking situations. These bots respond dynamically to situations as they unfold. The bots can easily be configured with scripts and can be used to experimentally manipulate social networking situations in Social Lab. Examples for setting up, configuring, and using Social Lab as a tool for research in social media are provided.

Mining twitter: a source for psychological wisdom of the crowds.

Over the last few years, microblogging has gained prominence as a form of personal broadcasting media where information and opinion are mixed together without an established order, usually tightly linked with current reality. Location awareness and promptness provide researchers using the Internet with the opportunity to create "psychological landscapes"--that is, to detect differences and changes in voiced (twittered) emotions, cognitions, and behaviors. In our article, we present iScience Maps, a free Web service for researchers, available from http://maps.iscience.deusto.es/ and http://tweetminer.eu/ . Technologically, the service is based on Twitter's streaming and search application programming interfaces (APIs), accessed through several PHP libraries, and a JavaScript frontend. This service allows researchers to assess via Twitter the effect of specific events in different places as they are happening and to make comparisons between cities, regions, or countries regarding psychological states and their evolution in the course of an event. In a step-by-step example, it is shown how to replicate a study on affective and personality characteristics inferred from first names (Mehrabian & Piercy, Personality and Social Psychology Bulletin, 19, 755-758 1993) by mining Twitter data with iScience Maps.Results from the original study are replicated in both world regions we tested (the western U.S. and the U.K./Ireland); we also discover base rate of names to be a confound that needs to be controlled for in future research.