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.

Evidence against implicit belief processing in a blindfold task.

Understanding what other people think is crucial to our everyday interactions. We seem to be affected by the perspective of others even in situations where it is irrelevant to us. This intrusion from others' perspectives has been referred to as altercentric bias and has been suggested to reflect implicit belief processing. There is an ongoing debate about how robust such altercentric effects are and whether they indeed reflect true mentalizing or result from simpler, domain-general processes. As a critical test for true mentalizing, the blindfold manipulation has been proposed. That is, participants are familiarized with a blindfold that is either transparent or opaque. When they then observe a person wearing this blindfold, they can only infer what this person can or cannot see based on their knowledge of the blindfold's transparency. Here, we used this blindfold manipulation to test whether participants' reaction times in detecting an object depended on the agent's belief about the object's location, itself manipulated with a blindfold. As a second task, we asked participants to detect where the agent was going to look for the object. Across two experiments with a large participant pool (N = 234) and different settings (online/lab), we found evidence against altercentric biases in participants' response times in detecting the object. We did, however, replicate a well-documented reality congruency effect. When asked to detect the agent's action, in turn, participants were biased by their own knowledge of where the object should be, in line with egocentric biases previously found in false belief reasoning. These findings suggests that altercentric biases do not reflect belief processing but lower-level processes, or alternatively, that implicit belief processing does not occur when the belief needs to be inferred from one's own experience.

Timing matters: disentangling the neurocognitive sequence of mentalizing.

A recent electrocorticographic study by Tan et al. makes an important contribution to understanding the processes involved in mentalizing by adding the temporal dimension to the brain network of mentalizing. Combined with multivariate methods, this approach has the potential to unveil the precise representations underlying mentalizing and their functional interplay.

The HEURECA method: Tracking multiple phase coupling dynamics on a single trial basis.

BACKGROUND: Although acquisition techniques have improved tremendously, the neuroscientific understanding of complex cognitive phenomena is still incomplete. One of the reasons for this shortcoming may be the lack of sophisticated signal processing methods. Complex cognitive phenomena usually involve various mental subprocesses whose temporal occurrence varies from trial to trial. Mostly, these mental subprocesses require large-scale integration processes between multiple brain areas that are most likely mediated by complex, non-linear phase coupling mechanisms. Consequently, a spatiotemporal analysis of complex, multivariate phase synchronization patterns on a single trial basis is necessary. NEW METHOD: This paper introduces the HEURECA method (How to Evaluate and Uncover Recurring EEG Coupling Arrangements) that enables the dynamic detection of distinguishable multivariate functional connectivity states in the electroencephalogram. HEURECA adaptively divides a trial into segments of quasi-stable phase coupling topographies and assigns similar topographies to the same synchrostate cluster. RESULTS: HEURECA is evaluated by means of simulated data. The results show that it reliably reconstructs a time series of recurring phase coupling topographies and successfully gathers them into clusters of interpretable neural synchrostates. The advantages and unique features of HEURECA are further illustrated by investigating the popular complex cognitive phenomenon insight. COMPARISON WITH EXISTING METHODS: Unlike existing methods, HEURECA detects complex phase relationships between more than two signals and is applicable to single trials. CONCLUSIONS: Since HEURECA is applicable to all kinds of circular data, it not only provides new insights into insight, but also into a variety of other phenomena in neuroscience, physics or other scientific fields.

New insights into insight: Neurophysiological correlates of the difference between the intrinsic "aha" and the extrinsic "oh yes" moment.

Insight refers to a situation in which a problem solver immediately changes his understanding of a problem situation. This representational change can either be triggered by external stimuli, like a hint or the solution itself, or by internal solution attempts. In the present paper, the differences and similarities between these two phenomena, namely "extrinsic" and "intrinsic" insight, are examined. To this end, electroencephalogram (EEG) is recorded while subjects either recognize or generate solutions to German verbal compound remote associate problems (CRA). Based on previous studies, we compare the alpha power prior to insightful solution recognition with the alpha power prior to insightful solution generation. Results show that intrinsic insights are preceded by an increase in alpha power at right parietal electrodes, while extrinsic insights are preceded by a respective decrease. These results can be interpreted in two ways. In consistency with other studies, the increase in alpha power before intrinsic insights can be interpreted as an increased internal focus of attention. Accordingly, the decrease in alpha power before extrinsic insights may be associated with a more externally oriented focus of attention. Alternatively, the increase in alpha power prior to intrinsic insights can be interpreted as an active inhibition of solution-related information, while the alpha power decrease prior to extrinsic insights may reflect its activation. Regardless of the interpretation, the results provide strong evidence that extrinsic and intrinsic insight differ on the behavioral as well as the neurophysiological level.