TANGO: A reliable, open-source, browser-based task to assess individual differences in gaze understanding in 3 to 5-year-old children and adults.

Traditional measures of social cognition used in developmental research often lack satisfactory psychometric properties and are not designed to capture variation between individuals. Here, we present the TANGO (Task for Assessing iNdividual differences in Gaze understanding-Open); a brief (approx. 5-10min), reliable, open-source task to quantify individual differences in the understanding of gaze cues. Localizing the attentional focus of an agent is crucial in inferring their mental states, building common ground, and thus, supporting cooperation. Our interactive browser-based task works across devices and enables in-person and remote testing. The implemented spatial layout allows for discrete and continuous measures of participants' click imprecision and is easily adaptable to different study requirements. Our task measures inter-individual differences in a child (N = 387) and an adult (N = 236) sample. Our two study versions and data collection modes yield comparable results that show substantial developmental gains: the older children are, the more accurately they locate the target. High internal consistency and test-retest reliability estimates underline that the captured variation is systematic. Associations with social-environmental factors and language skills speak to the validity of the task. This work shows a promising way forward in studying individual differences in social cognition and will help us explore the structure and development of our core social-cognitive processes in greater detail.

oREV: An item response theory-based open receptive vocabulary task for 3- to 8-year-old children.

Individual differences in early language abilities are an important predictor of later life outcomes. High-quality, easy-access measures of language abilities are rare, especially in the preschool and primary school years. The present study describes the construction of a new receptive vocabulary task for children between 3 and 8 years of age. The task was implemented as a browser-based web application, allowing for both in-person and remote data collection via the internet. Based on data from N = 581 German-speaking children, we estimated the psychometric properties of each item in a larger initial item pool via item response modeling. We then applied an automated item selection procedure to select an optimal subset of items based on item difficulty and discrimination. The so-constructed task has 22 items and shows excellent psychometric properties with respect to reliability, stability, and convergent and discriminant validity. The construction, implementation, and item selection process described here makes it easy to extend the task or adapt it to different languages. All materials and code are freely accessible to interested researchers. The task can be used via the following website: https://ccp-odc.eva.mpg.de/orev-demo .

Validation of an open source, remote web-based eye-tracking method (WebGazer) for research in early childhood.

Measuring eye movements remotely via the participant's webcam promises to be an attractive methodological addition to in-person eye-tracking in the lab. However, there is a lack of systematic research comparing remote web-based eye-tracking with in-lab eye-tracking in young children. We report a multi-lab study that compared these two measures in an anticipatory looking task with toddlers using WebGazer.js and jsPsych. Results of our remotely tested sample of 18-27-month-old toddlers (N = 125) revealed that web-based eye-tracking successfully captured goal-based action predictions, although the proportion of the goal-directed anticipatory looking was lower compared to the in-lab sample (N = 70). As expected, attrition rate was substantially higher in the web-based (42%) than the in-lab sample (10%). Excluding trials based on visual inspection of the match of time-locked gaze coordinates and the participant's webcam video overlayed on the stimuli was an important preprocessing step to reduce noise in the data. We discuss the use of this remote web-based method in comparison with other current methodological innovations. Our study demonstrates that remote web-based eye-tracking can be a useful tool for testing toddlers, facilitating recruitment of larger and more diverse samples; a caveat to consider is the larger drop-out rate.

The Ganzfeld experience-A stably inducible altered state of consciousness: Effects of different auditory homogenizations.

In the Ganzfeld technique, the visual and auditory perceptual fields are homogenized. After a short exposure to completely unstructured sensory input, participants transit into an altered state of consciousness. Visual homogenization is typically accomplished by a combination of goggles and bright light; auditory homogenization is accomplished by the presentation of unstructured auditory noise via headphones. The induced state is phenomenologically similar to a transition state between wakefulness and sleep, characterized by alterations in attentiveness, perception, and awareness, as well as by a compressed sense of time. Due to these replicable features of the Ganzfeld-induced state, it can be used within empirical research on the neuronal underpinnings of altered states phenomena. After a historic overview, here, we present data from a study on the stability of the subjectively experienced effects induced under different auditory homogenization conditions. In a fully randomized within-subject design (n = 24), we tested for the effects of three different auditory noise conditions: (1) violet, (2) white, and (3) brown noise. The combination of a standardized psychometric assessment, ratings on subjective time perception, as well as open reports prove the Ganzfeld-induced effects as being stable and effects within each participant as highly replicable, and therefore well suited for experimental purposes. Finally, the subjective experiences elucidated by the Ganzfeld technique are discussed within the framework of predictive coding and how changes in the interaction of top-down and bottom-up brain mechanisms could lead to the observed phenomenology.