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 that altercentric biases in a continuous false belief task depend on highlighting the agent’s belief

As social beings, we excel at understanding what other people think or believe. We even seem to be influenced by the belief of others in situations where it is irrelevant to our current tasks. Such altercentric interference has been proposed to reflect implicit belief processing. However, in which situations altercentric interference occurs and to what extent it is automatic or dependent on the relevance of the belief in context are open questions. To investigate this, we developed a novel task testing whether participants show an altercentric bias when searching for an object in a continuous search space (a ‘sandbox’). Critically, another agent is present that holds either a true or a false belief about the object location, depending on condition. We predicted that participants’ search for the object would deviate from its actual location in direction of where the agent believed the object to be. Further, we tested how this altercentric bias would interact with an explicit belief reasoning version of the task, where participants are asked where the agent would look for the object. In a large, preregistered study (N = 113), we found evidence for an altercentric bias in participants’ object search. Importantly, this bias was only present in participants who conducted the explicit before the implicit task. These findings indicate that altercentric biases depend on the relevance of the other’s belief in the context of the task, suggesting that spontaneous belief processing is not automatic but context dependent

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

AbstractMeasuring 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.</jats:p