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Survey research aims to collect robust and reliable data from respondents. However, despite researchers’ efforts in designing questionnaires, survey instruments may be imperfect, and question structure not as clear as could be, thus creating a burden for respondents. If it were possible to detect such problems, this knowledge could be used to predict problems in a questionnaire during pretesting, inform real-time interventions through responsive questionnaire design, or to indicate and correct measurement error after the fact. Previous research has used paradata, specifically response times, to detect difficulties and help improve user experience and data quality. Today, richer data sources are available, for example, movements respondents make with their mouse, as an additional detailed indicator for the respondent–survey interaction. This article uses machine learning techniques to explore the predictive value of mouse-tracking data regarding a question’s difficulty. We use data from a survey on respondents’ employment history and demographic information, in which we experimentally manipulate the difficulty of several questions. Using measures derived from mouse movements, we predict whether respondents have answered the easy or difficult version of a question, using and comparing several state-of-the-art supervised learning methods. We have also developed a personalization method that adjusts for respondents’ baseline mouse behavior and evaluate its performance. For all three manipulated survey questions, we find that including the full set of mouse movement measures and accounting for individual differences in these measures improve prediction performance over response-time-only models. German Research Foundation (DFG)

Survey participants' mouse movements provide a rich, unobtrusive source of paradata, and offer insight into the response process beyond the observed answers. However, the use of mouse-tracking may require participants' explicit consent that their movements are recorded and analyzed. Thus, the fundamental question arises how this affects the willingness of participants to take part in a survey at all -- if prospective respondents are reluctant to complete the survey if additional measures are collected, paradata collection may do more harm than good. Previous research has found that other paradata collection modes reduce the willingness to participate, and that this decrease may be influenced by the specific motivation provided to participants for collecting the data. However, the effects of mouse movement collection on survey consent and participation have not been addressed so far.In a vignette experiment, we show that willingness to participate in a survey decreased when mouse-tracking was part of the overall consent. However, a larger proportion of the sample was willing to both take part and provide mouse-tracking data when these decisions were combined, compared to an independent opt-in to paradata collection, separated from the decision to complete the study. This indicates that survey practitioners may face a trade-off between maximizing their overall participation rate and maximizing the number of participants that also provide mouse-tracking data. Explaining motivations for paradata collection did not have a positive effect and, in some cases, even reduced participants' willingness to participate.

When making risky choices, people often fall short of the norm of expected value (EV) maximization. Previous research has shown that presenting options in the Open Sampling (OSa) format, a 10-by-10 matrix of randomly arranged outcomes, can improve choices and reduce decision times. First, the current research aims to replicate and extend the findings on the OSa format. To this end, we compare OSa to the common description-based format as well as further graphical representations, and investigate the resulting accordance with EV maximization and decision time. Second, we study whether people lower (vs. higher) in numeracy, the ability to use probabilistic and mathematical concepts, particularly benefit from a graphical representation of options. We conducted five high-powered studies (total N = 1,575) in which participants chose repeatedly between two risky gambles, using different populations and gamble-problem sets. Overall, we could not find a benefit of the OSa format in terms of EV accordance in any of the five studies. However, three studies also tested a novel variant of the OSa format with grouped outcomes and found that it consistently improved EV accordance compared with all other formats. All graphical formats led to faster decisions without harming decision quality. The effects of presentation format were not moderated by numeracy in three of the four studies that assessed numeracy. In conclusion, our research introduces a new presentation format which consistently improves risky choices and can also be used to communicate risks in applied contexts such as medical decision making.

Online-Befragungen sind zu einer ublichen und haufig praferierten Datenerhebungsmethode geworden. Die hohe Flexibilitat und Anpassbarkeit ist ein wesentlicher Vorteil dieser Technologie. Die technischen Moglichkeiten werden oft von Umfrageentwicklern verwendet, beispielsweise um die Befragten mithilfe automatischer Filter durch den Fragebogen zu fuhren. Andere Features wie beispielsweise Mausbewegungen konnen eingesetzt werden, um einzelne Befragte zu identifizieren, die besonderer Aufmerksamkeit bedurfen. Forscher aus verschiedenen Disziplinen haben insbesondere die zuruckgelegte Distanz, den Pfad der Maus und andere Bewegungsmuster analysiert, um damit Interesse, Unsicherheit und aufgetretene Schwierigkeiten beim Befragten zu messen. Die aktuelle Studie strebt die Entwicklung von Indikatoren und automatischen Prozeduren an, mit deren Hilfe Schwierigkeiten des Befragten diagnostiziert und quantifiziert werden sollen. Zu diesem Zweck wird auf vielversprechende Indikatoren aus der vorherigen Forschung und auf jungste methodologische Fortschritte aus der Psychologie zuruckgegriffen. Die psychologische Literatur schlagt vor, auf Basis von Mausbewegungen den kognitiven Zwiespalt zwischen einzelnen Antwortalternativen bzw. die Unsicherheit bei der Auswahl zu beurteilen.

Movement tracking is a novel process tracing method promising unique access to the temporal dynamics of cognitive processes. The method involves high-resolution tracking of the hand or handheld devices, e.g., a computer mouse, while they are used to make a choice. In contrast to other process tracing methods, which mostly focus on information acquisition, movement tracking focuses on the processes of information integration and preference formation. In this article, we present a tutorial to movement tracking of cognitive processes with the mousetrap R package. We will address all steps of the research process from design to interpretation, with a particular focus on data processing and analysis. Using a representative working example, we will demonstrate how the various steps of movement tracking analysis can be implemented with mousetrap and provide thorough explanations on their theoretical background and interpretation. Finally, we present a list of recommendations to assist researchers in addressing their own research question using movement tracking of cognitive processes.

From an embodiment perspective, action and cognition influence each other constantly. This interaction has been utilized in mouse-tracking studies to infer cognitive states from movements, assuming a continuous manifestation of cognitive processing into movement. However, it is mostly unknown how this manifestation is affected by the variety of possible design choices in mouse-tracking paradigms. Here we studied how three design factors impact the manifestation of cognition into movement in a Simon task with mouse tracking. We varied the response selection (i.e., with or without clicking), the ratio between hand and mouse cursor movement, and the location of the response boxes. The results show that all design factors can blur or even prevent the manifestation of cognition into movement, as reflected by a reduction in movement consistency and action dynamics, as well as by the adoption of unsuitable movement strategies. We conclude that deliberate and careful design choices in mouse-tracking experiments are crucial to ensuring a continuous manifestation of cognition in movement. We discuss the importance of developing a standard practice in the design of mouse-tracking experiments. Electronic supplementary material The online version of this article (10.3758/s13414-019-01889-z) contains supplementary material, which is available to authorized users.

Investigating cognitive processes by analyzing mouse movements has become a popular method in many psychological disciplines. When creating mouse-tracking experiments, researchers face many design choices-for example, whether participants indicate responses by clicking a button or just by entering the button area. Hitherto, numerous different settings have been employed, but little is known about how these methodological differences affect mouse-tracking data. We systematically investigated the influences of three central design factors, using a classic mouse-tracking paradigm in which participants classified typical and atypical exemplars. In separate experiments, we manipulated the response indication, mouse sensitivity, and starting procedure. The core finding that mouse movements deviate more toward the nonchosen option for atypical exemplars was replicated in all conditions. However, the size of this effect varied. Specifically, it was larger when participants indicated responses via click and when they were instructed to initialize the movement early. Trajectory shapes also differed between setups. For example, a dynamic start led to mostly curved trajectories, responses via click led to a mix of straight and "change-of-mind" trajectories, and responses via touch led to mostly straight trajectories. Moreover, the distribution of curvature indices was classified as bimodal in some setups and as unimodal in others. Because trajectory curvature and shape are frequently used to make inferences about psychological theories, such as differentiating between dynamic and dual-system models, this study shows that the specific design must be carefully considered when drawing theoretical inferences. All methodological designs and analyses were implemented using open-source software and are available from https://osf.io/xdp7a/.

Previous research suggests that individuals with Borderline Personality Disorder (BPD) tend to evaluate other people as untrustworthy or hostile, which could contribute to the marked interpersonal problems in BPD. In contrast, alterations in first impressions of potential interaction partners of those with BPD remain under-researched and poorly understood. Herein, we focused on how naive raters evaluate BPD individuals, hypothesizing that raters would tend to evaluate them negatively. To test this hypothesis, we recruited 26 BPD and 26 healthy control participants (46% male) as targets in the ‘Thin Slices’ paradigm. Targets were video-taped while talking about their personal preferences (e.g. hobbies). Subsequently, these short videos (‘Thin Slices’) were presented to two rater samples (n = 92 and n = 44), who evaluated targets' likeability, trustworthiness, and cooperative behavior in an economic game. In both studies, raters evaluated BPD targets as less likeable and trustworthy, and in one study also as less cooperative. These findings are contrasted with results from an economic game, in which BPD targets behaved no less cooperatively than controls. We discuss limitations with regard to socioeconomic differences between the target groups and explore how negative evaluations by others may contribute to the interpersonal difficulties in BPD. We suggest that - given future replication with more strictly matched target groups- interventions aimed at improving impression management could be beneficial for BPD patients.

Individuals with Borderline Personality Disorder (BPD) or Social Anxiety Disorder (SAD) suffer from substantial interpersonal dysfunction and have difficulties establishing social bonds. A tendency to form negative first impressions of others could contribute to this by way of reducing approach behavior. We tested whether women with BPD or SAD would show negative impression formation compared to healthy women (HCs). We employed the Thin Slices paradigm and showed videos of 52 authentic target participants to 32 women with BPD, 29 women with SAD, and 37 HCs. We asked participants to evaluate whether different positive or negative adjectives described targets and expected BPD raters to provide the most negative ratings, followed by SAD and HC. BPD and SAD raters both agreed with negative adjectives more often than HCs (e.g., ‘Yes, the person is greedy’), and BPD raters rejected positive adjectives more often (e.g., ‘No, the person is not humble.’). However, BPD and SAD raters did not differ significantly from each other. Additionally, we used the novel process tracing method mouse-tracking to assess the cognitive conflict (via trajectory deviations) raters experienced during decision-making. We hypothesized that HCs would experience more conflict when making unfavorable (versus favorable) evaluations and that this pattern would flip in BPD and SAD. We quantified cognitive conflict via maximum absolute deviations (MADs) of the mouse-trajectories. As hypothesized, HCs showed more conflict when rejecting versus agreeing with positive adjectives. The pattern did not flip in BPD and SAD but was substantially reduced, such that BPD and SAD showed similar levels of conflict when rejecting and agreeing with positive adjectives. Contrary to the hypothesis for BPD and SAD, all three groups experienced substantial conflict when agreeing with negative adjectives. We discuss therapeutic implications of the combined choice and mouse-tracking results.

Multinomial processing tree models assume that discrete cognitive states determine observed response frequencies. Generalized processing tree (GPT) models extend this conceptual framework to continuous variables such as response times, process-tracing measures, or neurophysiological variables. GPT models assume finite-mixture distributions, with weights determined by a processing tree structure, and continuous components modeled by parameterized distributions such as Gaussians with separate or shared parameters across states. We discuss identifiability, parameter estimation, model testing, a modeling syntax, and the improved precision of GPT estimates. Finally, a GPT version of the feature comparison model of semantic categorization is applied to computer-mouse trajectories.

This study examined the relation between conservatism and life satisfaction. Analyses based on data from a representative German survey (ALLBUS 2010) revealed a positive relation between conservatism and self-reported life satisfaction, thus supporting prior claims of this link. Different accounts have been proposed for this relationship, suggesting system justification, positive adjustment, or multiple group membership as potential mediators. Going beyond prior research, this study allowed for a comparison between these different mechanisms. Analyses revealed that system justification and one of the three examined constructs related to positive adjustment (i.e., religiosity) were significant mediators of the positive relationship between political conservatismand life satisfaction. Comparable results were obtained after controlling for a number of sociodemographic variables. The present findings indicate (i) that conservatives report to be more satisfied with their lives than liberals and (ii) that this difference is in part due to conservatives’ system justification and religiosity.

Mouse- and hand-tracking has become a popular method for studying the cognitive processes involved in a variety of domains, including language processing, memory functions, social cognition, and preferential and moral decision making, to name just a few. The popularity of mouse- and hand-tracking derives from its promise to provide a window into the evolution of cognitive processes with an unrivaled temporal resolution. This window is opened by linking characteristics of the movement, such as the shape of its trajectory, to characteristics of the underlying cognitive process. In current research, this means, more often than not, inferring the response competition created by different conditions or stimuli based on the curvature of aggregate movement trajectories. However, we will argue that this aggregate-level approach risks obscuring important trial-level variability in movement trajectories that can paint a different picture of the underlying cognitive process than the aggregate-level results do. Fortunately, mouse-tracking can do much more. In this chapter, we present a new approach to analyzing mouse-trajectories based on trajectory clustering that overcomes the limitations of aggregation-based analyses of movement trajectories.

Web-based data collection is increasingly popular in both experimental and survey-based research because it is flexible, efficient, and location-independent. While dedicated software for laboratory-based experimentation and online surveys is commonplace, researchers looking to implement experiments in the browser have, heretofore, often had to manually construct their studies’ content and logic using code. We introduce , a free, open-source experiment builder that makes it easy to build studies for both online and in-laboratory data collection. Through its visual interface, stimuli can be designed and combined into a study without programming, though studies’ appearance and behavior can be fully customized using html, css, and JavaScript code if required. Presentation and response times are kept and measured with high accuracy and precision heretofore unmatched in browser-based studies. Experiments constructed with can be run directly on a local computer and published online with ease, with direct deployment to cloud hosting, export to web servers, and integration with popular data collection platforms. Studies can also be shared in an editable format, archived, re-used and adapted, enabling effortless, transparent replications, and thus facilitating open, cumulative science. The software is provided free of charge under an open-source license; further information, code, and extensive documentation are available from https://lab.js.org/.

Mouse-tracking is an increasingly popular process-tracing method. It builds on the assumption that the continuity of cognitive processing leaks into the continuity of mouse movements. Because this assumption is the prerequisite for meaningful reverse inference, it is an important question whether the assumed interaction between continuous processing and movement might be influenced by the methodological setup of the measurement. Here we studied the impacts of three commonly occurring methodological variations on the quality of mouse-tracking measures, and hence, on the reported cognitive effects. We used a mouse-tracking version of a classical intertemporal choice task that had previously been used to examine the dynamics of temporal discounting and the date-delay effect (Dshemuchadse, Scherbaum, & Goschke, 2013). The data from this previous study also served as a benchmark condition in our experimental design. Between studies, we varied the starting procedure. Within the new study, we varied the response procedure and the stimulus position. The starting procedure had the strongest influence on common mouse-tracking measures, and therefore on the cognitive effects. The effects of the response procedure and the stimulus position were weaker and less pronounced. The results suggest that the methodological setup crucially influences the interaction between continuous processing and mouse movement. We conclude that the methodological setup is of high importance for the validity of mouse-tracking as a process-tracing method. Finally, we discuss the need for standardized mouse-tracking setups, for which we provide recommendations, and present two promising lines of research toward obtaining an evidence-based gold standard of mouse-tracking.

We introduce a novel platform for interactive studies, that is, any form of study in which participants' experiences depend not only on their own responses, but also on those of other participants who complete the same study in parallel, for example a prisoner's dilemma or an ultimatum game. The software thus especially serves the rapidly growing field of strategic interaction research within psychology and behavioral economics. In contrast to all available software packages, our platform does not handle stimulus display and response collection itself. Instead, we provide a mechanism to extend existing experimental software to incorporate interactive functionality. This approach allows us to draw upon the capabilities already available, such as accuracy of temporal measurement, integration with auxiliary hardware such as eye-trackers or (neuro-)physiological apparatus, and recent advances in experimental software, for example capturing response dynamics through mouse-tracking. Through integration with OpenSesame, an open-source graphical experiment builder, studies can be assembled via a drag-and-drop interface requiring little or no further programming skills. In addition, by using the same communication mechanism across software packages, we also enable interoperability between systems. Our source code, which provides support for all major operating systems and several popular experimental packages, can be freely used and distributed under an open source license. The communication protocols underlying its functionality are also well documented and easily adapted to further platforms. Code and documentation are available at https://github.com/psynteract/ .

Recent studies reported an increase in the dentate nucleus (DN)-to-pons signal intensity (SI) ratio (DN-pons SI ratio) on unenhanced T1-weighted images in patients who received consecutive serial injections of linear gadolinium-based contrast agents (GBCAs). In contrast, most studies found no increase in the DN-pons SI ratio when patients were treated with consecutive serial injections of macrocyclic GBCAs. However, the potential difference between macrocyclic and linear GBCAs has never been assessed in individuals who received subsequent applications of both contrast agents. In this retrospective study, we assessed the evolution of the DN-pons SI ratio change in patients that were treated with a comparable number of serial consecutive injections of the linear GBCA gadopentetate dimeglumine and subsequent serial injections of the macrocyclic GBCAs gadobutrol and gadoterate meglumine.Data of 36 patients was analyzed. All patients underwent at least 5 consecutive administrations of the linear GBCA gadopentetate dimeglumine followed by an equal number of consecutive administrations of the macrocyclic GBCA gadobutrol. In 12 of the 36 patients, 5 or more final consecutive injections of the macrocyclic GBCA gadoterate meglumine were analyzed additionally. The difference of DN-pons SI ratios on unenhanced T1-weighted images was calculated by subtracting the ratio at the first examination from the ratio at the last examination in each of the 3 periods.The mean DN-pons SI ratio difference in the gadopentetate dimeglumine period was significantly greater than 0 (mean ± SD, 0.0448 ± 0.0345; P0.001), whereas the mean DN-pons SI ratio difference in the subsequent gadobutrol and gadoterate meglumine period was significantly smaller than 0 (gadobutrol: -0.0178 ± 0.0459, P = 0.026; gadoterate meglumine: -0.0250 ± 0.0284, P = 0.011).In this observational study, the application of the linear GBCA gadopentetate dimeglumine was associated with a DN-pons SI ratio increase, whereas subsequent applications of the macrocyclic GBCAs gadobutrol or gadoterate meglumine in the same patients were not. Rather, the current data tentatively suggest a decrease in preexisting hyperintensities over time when linear GBCAs are changed to macrocyclic GBCAs, potentially indicating a washout effect or precipitation of gadolinium. Future patient studies need to include control groups to replicate the present results, and additional animal studies should be conducted to clarify the underlying mechanism of the proposed SI decrease.

The aim of this study was to compare changes in the signal intensity (SI) ratio of the dentate nucleus (DN) to the pons, DN to cerebrospinal fluid (CSF), and globus pallidus (GP) to thalamus on unenhanced T1-weighted magnetic resonance imaging (MRI) scans after serial injections of the macrocyclic gadolinium-based contrast agent gadobutrol.Thirty patients who had received at least 5 MRI examinations (plus an additional last MRI for reference) with the exclusive use of gadobutrol, resulting in a total cumulative dose of 54.1 ± 30.4 mL gadobutrol, were analyzed retrospectively. Signal intensity ratio differences were calculated for DN-to-pons, DN-to-CSF, and GP-to-thalamus ratios by subtracting the SI ratio at the first MRI from the SI ratio at the last MRI scan. One-sample t tests were employed to examine if they differed from 0. Regression and correlational analyses were performed to examine whether the SI ratio differences were predicted by a number of control variables.Signal intensity ratio differences did not differ significantly from 0, neither for the DN-to-pons ratio (-0.0035 ± 0.0476, P = 0.69), the DN-to-CSF ratio (-0.0539 ± 0.3217, P = 0.37), nor the GP-to-thalamus ratio (-0.0020 ± 0.0211, P = 0.60). None of the control variables predicted changes in SI ratios.In contrast to a recently published study, we did not find signal increases in the DN or in the GP after serial injections of gadobutrol, even though the total dose applied here was considerably larger than in the respective study. This finding adds further support to the hypothesis that the molecular structure of a gadolinium-based contrast agent as either macrocyclic or linear is a crucial factor for its potential to cause gadolinium deposition in the brain. Future studies should further assess this hypothesis by additional animal investigations as well as histopathological and clinical correlation studies.

Background Several recent studies have demonstrated that naïve raters tend to evaluate individuals with Borderline Personality Disorder (BPD) negatively at zero-acquaintance (i.e., in a ‘first impression’ type situation, where the rater has no knowledge of the individual and no prior interactions with them). Specifically, individuals with BPD were evaluated as less trustworthy, likeable, and cooperative than healthy participants (HCs). Based on previous impression formation studies, we hypothesized that the non-verbal cues positive affect display, negative affect display, and eye contact contribute to negative first impressions of those with BPD. Methods To address this question, we recruited 101 participants that rated the degree of positive affect display, negative affect display, and eye contact in 52 videos of age-and gender-matched BPD and HC participants. We hypothesized that low positive affect display, high negative affect display, and eye contact would mediate the association between group (BPD vs. HC) and ratings of trustworthiness, likeability, and cooperativeness. Results Ratings for positive affect display were significantly lower and those for negative affect display significantly higher for BPD versus HC targets, whereas eye contact did not differ significantly between groups. In multiple mediation models, positive affect display significantly mediated the association between group and trustworthiness/likeability, whereas negative affect display only mediated the association between group and likeability. None of the individual cues was a significant mediator of the association between group and cooperation. Conclusions We emphasize therapeutic possibilities to improve positive affect display –and thus overall first impressions– to increase the chances of forming social bonds for BPD individuals.

In this study, we aimed to explore whether action execution is an inherent part of the decision-making process. According to the hypothesis of embodied choice, the decision-making process is bidirectional as action dynamics exert their backward influence on decision processes through changing the cost and value of the potential options. This influence takes place as moving toward one option increases the commitment to and, therefore, the likelihood of choosing that option. This commitment effect can be the result of either (a) the continuous act of getting closer to this option or (b) the increased movement cost associated with changing the movement direction to select a different option. To disentangle the potential influence of these two factors, we developed the Guided Movement Task, a choice task designed to bias participant's computer-mouse movements by constraining the allowed movement space by a corridor. Using this task, we created different conditions in which the participants' mouse cursor, after being guided toward one of the options, either had equal or unequal distances to the choice options. By this manipulation, we could test whether the continuous act of getting closer to an option in itself is sufficient to influence people's decisions-a claim of "strong embodiment." In two experiments, we found that the likelihood of choosing an option only increased when the distances between the two options were unequal after the initial movement but not when they were equal. These results disagree with the hypothesis that action execution is an inherent part of the decision-making process. (PsycINFO Database Record

The aim of this study was to compare changes in signal intensity (SI) ratios of the dentate nucleus (DN) to pons and cerebrospinal fluid (CSF) on unenhanced T1-weighted magnetic resonance imaging (MRI) scans between the first and last MRI using the linear gadolinium-based contrast agent gadobenate dimeglumine.The study was approved by the ethical committee of the University of Heidelberg (S-324/2014), and written informed consent was waived due to the retrospective character of the study. Fifty patients who underwent at least 5 consecutive MRI examinations (plus an additional last MRI for reference) with the exclusive use of gadobenate dimeglumine were analyzed retrospectively. The difference of DN-to-pons and DN-to-CSF mean SI ratios was calculated on unenhanced T1-weighted images between the first and last examination. Results were compared with previously published data on gadopentetate dimeglumine and gadoterate meglumine.Signal intensity ratio differences for DN-to-pons and DN-to-CSF were significantly greater than 0 (pons: 0.0399 ± 0.0307, P0.001; CSF: 0.1439 ± 0.1524, P0.001). No control variable consistently predicted the SI ratio difference for the DN-to-pons and the DN-to-CSF ratio. Compared with previously published data, the difference in SI increase between gadopentetate dimeglumine and gadobenate dimeglumine was not significant for the DN-to-pons ratio (P = 0.906). In contrast, the DN-to-CSF ratio difference was significantly lower (P0.001) for gadobenate dimeglumine. Dentate nucleus-to-pons (P0.001) and DN-to-CSF (P = 0.017) ratio differences were both significantly higher for gadobenate dimeglumine than for gadoterate meglumine.The present study found an increase in SI in the DN after serial injections of gadobenate dimeglumine. Further studies are needed to clarify the potential of different linear gadolinium-based contrast agents to cause SI increase in the DN.

Mouse-tracking is an increasingly popular method to trace cognitive processes. As is common for a novel method, the exact methodological procedures employed in an individual study are still relatively idiosyncratic and the effects of different methodological setups on mouse-tracking measures have not been explored so far. Here, we study the impact of one commonly occurring methodological variation, namely whether participants have to initiate their mouse movements to trigger stimulus presentation (dynamic starting condition) or whether the stimulus is presented automatically after a fixed delay and participants can freely decide when to initiate their movements (static starting condition). We compared data from a previous study in which participants performed a mouse-tracking version of a Simon task with a dynamic starting condition to data from a new study that employed a static starting condition in an otherwise identical setup. Results showed reliable Simon effects and Congruency Sequence effects on response time (RT) and discrete trial-level mouse-tracking measures (i.e., average deviation) in both starting conditions. In contrast, within-trial continuous measures (i.e., extracted temporal segments) were weaker and occurred in a more temporally compressed way in the static compared to the dynamic starting condition. This was in line with generally less consistent movements within and across participants in the static compared to the dynamic condition. Our results suggest that studies that use within-trial continuous measures to assess dynamic aspects of mouse movements should apply dynamic starting procedures to enhance the leakage of cognitive processing into the mouse movements.

Mouse-tracking – the analysis of mouse movements in computerized experiments – is becoming increasingly popular in the cognitive sciences. Mouse movements are taken as an indicator of commitment to or conflict between choice options during the decision process. Using mouse-tracking, researchers have gained insight into the temporal development of cognitive processes across a growing number of psychological domains. In the current article, we present software that offers easy and convenient means of recording and analyzing mouse movements in computerized laboratory experiments. In particular, we introduce and demonstrate the mousetrap plugin that adds mouse-tracking to OpenSesame, a popular general-purpose graphical experiment builder. By integrating with this existing experimental software, mousetrap allows for the creation of mouse-tracking studies through a graphical interface, without requiring programming skills. Thus, researchers can benefit from the core features of a validated software package and the many extensions available for it (e.g., the integration with auxiliary hardware such as eye-tracking, or the support of interactive experiments). In addition, the recorded data can be imported directly into the statistical programming language R using the mousetrap package, which greatly facilitates analysis. Mousetrap is cross-platform, open-source and available free of charge from https://github.com/pascalkieslich/mousetrap-os .

Purpose To correlate histopathologic findings from biopsy specimens with their corresponding location within enhancing areas, non-enhancing areas and necrotic areas on contrast enhanced T1-weighted MRI scans (cT1). Materials and Methods In 37 patients with newly diagnosed glioblastoma who underwent stereotactic biopsy, we obtained a correlation of 561 1mm3 biopsy specimens with their corresponding position on the intraoperative cT1 image at 1.5 Tesla. Biopsy points were categorized as enhancing (CE), non-enhancing (NE) or necrotic (NEC) on cT1 and tissue samples were categorized as “viable tumor cells”, “blood” or “necrotic tissue (with or without cellular component)”. Cell counting was done semi-automatically. Results NE had the highest content of tissue categorized as viable tumor cells (89% vs. 60% in CE and 30% NEC, respectively). Besides, the average cell density for NE (3764 ± 2893 cells/mm2) was comparable to CE (3506 ± 3116 cells/mm2), while NEC had a lower cell density with 2713 ± 3239 cells/mm2. If necrotic parts and bleeds were excluded, cell density in biopsies categorized as “viable tumor tissue” decreased from the center of the tumor (NEC, 5804 ± 3480 cells/mm2) to CE (4495 ± 3209 cells/mm2) and NE (4130 ± 2817 cells/mm2). Discussion The appearance of a glioblastoma on a cT1 image (circular enhancement, central necrosis, peritumoral edema) does not correspond to its diffuse histopathological composition. Cell density is elevated in both CE and NE parts. Hence, our study suggests that NE contains considerable amounts of infiltrative tumor with a high cellularity which might be considered in resection planning.

Purpose: To determine the effect of more than 20 serial injections of macrocyclic gadolinium-based contrast agents (GBCAs) on the signal intensity (SI) of the dentate nucleus (DN) on unenhanced T1-weighted magnetic resonance (MR) images. Materials and Methods: In this retrospective, institutional review board-Approved study, 33 patients who underwent at least 20 consecutive MR imaging examinations (plus an additional MR imaging for reference) with the exclusive use of macrocyclic GBCAs gadoterate meglumine and gadobutrol were analyzed. SI ratio differences were calculated for DN-To-pons and DNto- middle cerebellar peduncle (MCP) ratios by subtracting the SI ratio at the first MR imaging examination from the SI ratio at the last MR imaging examination. One-sample t tests were used to examine if the SI ratio differences differed from 0, and Bayes factors were calculated to quantify the strength of evidence for each test. Results: Patients underwent a mean of 23.03 6 (standard deviation) 4.20 GBCA administrations (mean accumulated dose, 491.21 mL 6 87.04 of a 0.5 M GBCA solution) with an average of 12.09 weeks 6 2.16 between every administration. Both ratio differences did not differ significantly from 0 (DN-To-pons ratio: 20.0032 6 0.0154, P = .248; DN-To-MCP ratio: 20.0011 6 0.0093, P = .521), and one-sided Bayes factors provided substantial to strong evidence against an SI ratio increase (Bayes factor for DN-Topons ratio = 0.09 and that for DN-To-MCP ratio = 0.12). Conclusion: The study indicates that 20 or more serial injections of macrocyclic GBCAs administered with on average 3 months between each injection are not associated with an SI increase in the DN.

Objective Several studies have analyzed a correlation between the apparent diffusion coefficient (ADC) derived from diffusion-weighted MRI and the tumor cellularity of corresponding histopathological specimens in brain tumors with inconclusive findings. Here, we compared a large dataset of ADC and cellularity values of stereotactic biopsies of glioblastoma patients using a new postprocessing approach including trajectory analysis and automatic nuclei counting. Materials and Methods Thirty-seven patients with newly diagnosed glioblastomas were enrolled in this study. ADC maps were acquired preoperatively at 3T and coregistered to the intraoperative MRI that contained the coordinates of the biopsy trajectory. 561 biopsy specimens were obtained; corresponding cellularity was calculated by semi-automatic nuclei counting and correlated to the respective preoperative ADC values along the stereotactic biopsy trajectory which included areas of T1-contrast-enhancement and necrosis. Results There was a weak to moderate inverse correlation between ADC and cellularity in glioblastomas that varied depending on the approach towards statistical analysis: for mean values per patient, Spearman’s ρ = -0.48 (p = 0.002), for all trajectory values in one joint analysis Spearman’s ρ = -0.32 (p < 0.001). The inverse correlation was additionally verified by a linear mixed model. Conclusions Our data confirms a previously reported inverse correlation between ADC and tumor cellularity. However, the correlation in the current article is weaker than the pooled correlation of comparable previous studies. Hence, besides cell density, other factors, such as necrosis and edema might influence ADC values in glioblastomas.

Zielsetzung: Aktuelle Studien zeigen Steigerungen der Signalintensitat (SI) und Gadoliniumablagerungen im Nucleus Dentatus (ND) und Globus Pallidus (GP) nach Gabe Gadoliniumhaltiger Kontrastmittel im MRT. Wahrend dieses Phanomen bisher vor allem auf lineare Kontrastmittel beschrankt war und bei makrozyklischen keine Auswirkungen gezeigt werden konnten, zeigt eine aktuelle Studie Ablagerungen in Multiple Sklerose-Patienten nach Gabe des makrozyklischen Kontrastmittels Gadobutrol. Dies mochten wir auf seine Reproduzierbarkeit hin prufen. Material und Methodik: Die Ethikkommission stimmte dieser retrospektiven Studie zu (S-324/2014), eine Einwilligungserklarung war nicht vonnoten. 33 Patieten mit min. sechs seriellen Gadobutrol-verstarkten MRT's wurden retrospektiv untersucht. Zur Pons (ND) und zum Thalamus (GP) relative SI wurden Region-of-interest-basiert gemessen und die Differenz des letzten und ersten MRT mit Gadobutrol wurde gebildet. Statistisch gerechnet wurde mit einem T-Test fur unverbundene Stichproben und einer Korrelationsanalyse, um mogliche Storfaktoren zu identifizieren. Ergebnisse: Die relative SI-Differenz zwischen letztem und erstem MRT unterschied sich nicht signifikant von null, weder fur den ND (-0,0035 ± 0,0476, p =,69), noch fur den GP (-0,0020 ± 0,0211, p =,60). Die gesamte kumulative Dosis an Gadobutrol war 54,1 ± 30,4 ml. Keiner der potenziellen Storfaktoren konnte signifikant die SI vorhersagen. Schlussfolgerungen: Im Gegensatz zu einer anderen Studie konnten wir keine Steigerung der SI im ND und GP nach Gadobutrol feststellen, obwohl unsere mittlere Dosis hoher war (54,1 ml gegen 33.3 ml). Ein moglicher Erklarungsansatz sind abweichende Diagnosen (31/33 sind Tumorpatienten) in unserer Studie. Dies bekraftigt die momentan wahrscheinlichste Hypothese, dass die Stabilitatsunterschiede zwischen den linearen und makrozyklische Gadolinium-Chelaten das entscheidende Kriterium fur Ablagerungen im ND und GP sind. Weitere Studien sollten dies histopathologisch bestatigen und mogliche klinische Korrelate erheben.

Background Many studies have assessed emotion recognition in patients with Borderline Personality Disorder and considerable evidence has been accumulated on patients’ ability to categorize emotions. In contrast, their ability to detect emotions has been investigated sparsely. The only two studies that assessed emotion detection abilities found contradictory evidence on patients’ ability to detect angry faces. Methods To clarify whether patients with Borderline Personality Disorder show enhanced detection of angry faces, we conducted three experiments: a laboratory study (n = 53) with a clinical sample and two highly powered web studies that measured Borderline features (n1 = 342, n2 = 220). Participants in all studies completed a visual search paradigm, and the reaction times for the detection of angry vs. happy faces were measured. Results Consistently, data spoke against enhanced detection of angry faces in the Borderline groups, indicated by non-significant group (Borderline vs. healthy control) × target (angry vs. happy) interactions, despite highly satisfactory statistical power to detect even small effects. Conclusions In contrast to emotion categorization, emotion detection appears to be intact in patients with Borderline Personality Disorder and individuals high in Borderline features. The importance of distinguishing between these two processes in future studies is discussed.

To compare changes in signal intensity (SI) ratios of the dentate nucleus (DN) and the globus pallidus (GP) to those of other structures on unenhanced T1-weighted magnetic resonance (MR) images between linear and macrocyclic gadolinium-based contrast agents (GBCAs).The study was approved by the ethical committee of the University of Heidelberg (reference no. S-324/2014). Owing to the retrospective character of the study, the ethical committee did not require any written informed consent. Two groups of 50 patients who underwent at least six consecutive MR imaging examinations with the exclusive use of either a linear GBCA (gadopentetate dimeglumine) or a macrocyclic GBCA (gadoterate meglumine) were analyzed retrospectively. The difference in mean SI ratios of DN to pons and GP to thalamus on unenhanced T1-weighted images from the last and first examinations was calculated. One-sample and independent-sample t tests were used to assess the difference in SI ratios for both groups, and regression analysis was performed to account for potential confounders.The SI ratio difference in the linear group was greater than 0 (mean DN difference ± standard deviation, 0.0407 ± 0.0398 [P.001]; GP, 0.0287 ± 0.0275 [P.001]) and significantly larger (DN, P.001 and standardized difference of 1.16; GP, P.001 and standardized difference of 0.81) than that in the macrocyclic group, which did not differ from 0 (DN, 0.0016 ± 0.0266 [P = .680]; GP, 0.0031 ± 0.0354 [P = .538]). The SI ratio difference between the last and first examinations for the DN remained significantly different between the two groups in the regression analysis (P.001).This study indicates that an SI increase in the DN and GP on T1-weighted images is caused by serial application of the linear GBCA gadopentetate dimeglumine but not by the macrocyclic GBCA gadoterate meglumine. Clinical implications of this observation remain unclear.

Background and Purpose Due to its sensitivity to deoxyhemoglobin, susceptibility weighted imaging (SWI) enables the visualization of deep medullary veins (DMV) in patients with acute stroke, which are difficult to depict under physiological circumstances. This study assesses the asymmetric appearance of prominent DMV as an independent predictor for stroke severity and outcome. Materials and Methods SWI of 86 patients with acute middle cerebral artery (MCA) stroke were included. A scoring system from 0 (no visible DMV) to 3 (very prominent DMV) was applied for both hemispheres separately. A difference of scores between ipsi- and contralateral side was defined as asymmetric (AMV+). Occurrence of AMV+ was correlated with the National Institute of Health Stroke Scale (NIHSS) Score on admission and discharge, as well as the modified Rankin Scale (mRS) at discharge. Ordinal regression analysis was used to evaluate NIHSS and mRS as predictors of stroke severity, clinical course of disease and outcome. Results 55 patients displayed AMV+ while 31 did not show an asymmetry (AMV–). Median NIHSS on admission was 17 (11–21) in the AMV+ group and 9 (5–15) in the AMV– group (p = 0.001). On discharge median NIHSS was 11 (5–20) for AMV+ and 5 (2–14) for AMV– (p = 0.005). The median mRS at discharge was 4 (3–5) in the AMV+ group and 3 (1–4) in AMV– (p = 0.001). Odds ratio was 3.19 (95% CI: 1.24–8.21) for AMV+ to achieve a higher mRS than AMV– (p = 0.016). Conclusion The asymmetric appearance of DMV on SWI is a fast and easily evaluable parameter for the prediction of stroke severity and can be used as an additional imaging parameter in patients with acute MCA stroke.

Recently, it has been suggested that people are spontaneously inclined to cooperate in social dilemmas, whereas defection requires effortful deliberation. From this assumption, we derive that defection should entail more cognitive conflict than cooperation. To test this hypothesis, the current study presents a first application of the response dynamics paradigm (i.e., mouse-tracking) to social dilemmas. In a fully incentivized lab experiment, mouse movements were tracked while participants played simple two-person social dilemma games with two options (cooperation and defection). Building on previous research, curvature of mouse movements was taken as an indicator of cognitive conflict. In line with the hypothesis of less cognitive conflict in cooperation, response trajectories were more curved (towards the non-chosen option) when individuals defected than when they cooperated. In other words, the cooperative option exerted more “pull” on mouse movements in case of defection than the non-cooperative option (defection) did in case of cooperation. This effect was robust across different types of social dilemmas and occurred even in the prisoner’s dilemma, where defection was predominant on the choice level. Additionally, the effect was stronger for dispositional cooperators as measured by the Honesty-Humility factor of the HEXACO personality model. As such, variation in the effect across individuals could be accounted for through cooperativeness.

Myrseth and Wollbrant (2015) offer an alternative theoretical explanation for our finding that defection entails more cognitive conflict than cooperation (Kieslich & Hilbig, 2014). Although we completely agree that different theoretical explanations for a result are possible, we maintain that the theoretical approach we tested (Rand et al., 2014) is parsimonious and falsifiable, excluding certain plausible results a priori. By comparison, the alternative framework proposed by Myrseth and Wollbrant requires several debatable assumptions to account for our findings, rendering it the more complex theory. Besides, their framework as a whole could have accounted for any possible finding in our experiment, making it impossible to falsify it with our data. We thus conclude that the notion by Rand et al.—that there is a spontaneous disposition to cooperate—has more empirical content while requiring fewer assumptions.

This thesis addresses the topic of mouse-tracking, that is, the recording and analysis of mouse movements in computerized experiments. Mouse-tracking is an increasingly popular process tracing method in many psychological disciplines as it allows capturing the temporal development of the relative attraction to and conflict between response alternatives. It thus provides the opportunity to test psychological theories about factors that influence the conflict involved in making a decision, and how this conflict develops over time. So far, researchers have faced a number of difficulties when conducting mouse-tracking studies: There has been no easy-to-use, flexible and open software for creating experiments and no general-purpose package for analysis. Researchers also have had to make many choices regarding the study setup, with no evidence-based guidelines to support their decisions. This thesis aims to provide solutions for these challenges. First, this thesis introduces free and open-source software packages for creating and analyzing mouse-tracking experiments. The mousetrap plugin enables researchers to implement mouse-tracking in their experiments without programming and, through integration with the experiment builder OpenSesame, offers a graphical user interface that makes it easy to create a variety of experiments and designs. The mousetrap R package provides extensive functionality for processing, analyzing, and visualizing mouse-tracking raw data of all major formats. It implements most of the commonly used preprocessing procedures and mouse-tracking indices, as well as a set of novel visualization and classification procedures for analyzing trajectory shapes. Second, this thesis presents results from a series of experiments that investigate how the methodological setup influences mouse-tracking data. In separate experiments, I manipulated the design factors starting procedure, mouse sensitivity, and response indication and investigated their impact on trajectory curvature and shape. An additional study investigated the effects of the starting procedure on movement consistency and also included dynamic analyses. While central cognitive effects on trajectory curvature were replicated in all setups, their size varied considerably between some of the setups. In addition, the setup strongly influenced the trajectory shapes and dynamic analyses. Based on this evidence, I discuss implications for interpreting mouse-tracking data and offer preliminary recommendations for conducting mouse-tracking experiments. In sum, I hope this thesis will contribute to advancing mouse-tracking research and making the method accessible to a broader audience.

Judgments and decisions can rely on rules to integrate cue information or on the retrieval of similar exemplars from memory. Research on exemplar-based processes in judgment has discovered several task variables influencing the dominant mode of processing. This research often aggregates data across participants or classifies them as using either exemplar-based or cue-based processing. It has been argued for theoretical and empirical reasons that both kinds of processes might operate together or in parallel. Hence, a classification of strategies may be a severe oversimplification that also sacrifices statistical power to detect task effects. We present a simple measurement tool combining both processing modes. The simple model contains a mixture parameter quantifying the relative contribution of both kinds of processes in a judgment and decision task. In three experiments, we validate the measurement model by demonstrating that instructions and task variables affect the mixture parameter in predictable ways, both in memory-based and screen-based judgments.

Most decision-making models describing individual differences in heuristics and biases tasks build on the assumption that reasoners produce a first incorrect answer in a quick, automatic way which they may or may not override later and that the advantage of high capacity reasoners arises from this late correction mechanism. To investigate this assumption, we developed a mouse-tracking analysis technique to capture individuals’ first answers and subsequent thinking dynamics. Across two denominator neglect task experiments, we observed that individuals initially move the mouse cursor towards the correct answer option in a substantial number of cases suggesting that reasoners may not always produce an incorrect answer first. Furthermore, we observed that, compared to low capacity reasoners, high capacity individuals revise their first answer more frequently if it is incorrect and make fewer changes if it is correct. However, we did not find evidence that high capacity individuals produce correct initial answers more frequently. Consistent with the predictions of previous decision-making models, these results suggest that in the denominator neglect task the capacity-normativity relationship arises after the initial response is formulated. The present work demonstrates how the analysis of mouse trajectories can be utilized to investigate individual differences in decision-making and help us better apprehend the dynamics of thinking behind decision biases.