Conduct eye tracking studies more efficiently

The Advanced Screen is a new project type within Tobii Pro Lab. It simplifies the design of screen-based eye tracking studies for behavioral research and allows researchers to easily create and control complex experiments.

Advanced Screen – more flexibility when designing complex experiments

Research methods in cognitive psychology, linguistics, and developmental psychology involve carefully designed experiments to investigate the effects of independent variables on dependent variables related to underlying cognitive processes. These designs can be complex and involve repeating many sets of stimuli, often presented in multiple combinations. Unfortunately, manually creating these stimuli and combinations can be a labor-intensive and time-consuming process.

To address this challenge, Tobii has introduced the Advanced Screen - a new project type in Tobii Pro Lab (ASP) to simplify the process of designing and conducting screen-based eye tracking studies. With the ASP, researchers can plan and design the trials of their experiment in a spreadsheet outside of Pro Lab and create an experimental structure with stimuli sequences within Pro Lab using the spreadsheet’s content as input. The image files that comprise a stimulus can also be utilized as areas of interest (AOIs) when analyzing eye-tracking data, there is no need to build AOIs manually.

The ASP enables researchers to easily create new stimuli, randomize trials and control complex experimental designs involving many stimuli without the need for manually building those stimuli. This allows researchers to spend more time on their research and data analysis, ultimately leading to greater efficiency.

Let us look at two specific examples that demonstrate the capabilities of the ASP.

Preferential looking studies – exploring infant cognition through visual behavior

Preferential looking (PL) studies, which are popular in infant research, constitute a prime example of a study paradigm supported by ASP. The experiment usually consists of objects presented side-by-side on a screen and aims to investigate cognitive development in infants. Researchers then record the eye movements to infer whether the infant can distinguish between categories or to study preferences. For example, Fernald and colleagues (1998) showed that infants between 6 and 9 months prefer to look at less familiar objects compared to familiar objects. A study by Quinn and Eimas (1996) found that 5-month-old babies look longer at pictures of animals compared to inanimate objects suggesting a preference for animals. This study can be a concrete example of how ASP simplifies stimulus construction. In an experiment with four different animals and inanimate objects, each animal must be combined with each inanimate object. Each image needs to be presented once on the left and once on the right side of the screen, already resulting in 32 (4x4x2) different stimuli (Picture 1).

This is a great example of a design that would highly profit from ASP because there is no need to create these stimuli manually as everything can be set up in a spreadsheet. Picture 2 illustrates how to set up an experiment in the ASP using this design as an example.  

Explore the features in Tobii Pro Lab to design and analyze a preferential looking paradigm. 

Watch our demo walkthrough and download the sample project.

The visual world paradigm – tracking eye movements to investigate language processing in real-time

PL studies are just one of many possible examples of study paradigms supported by ASP; another one is the Visual World Paradigm (VWP). The VWP is a popular cognitive psychology and linguistics research method to investigate the cognitive processes underlying language processing in real time. The VWP was pioneered by Cooper (1974) and Tanenhaus et al. (1995). Participants look at a visual scene while listening to auditory stimuli such as a sentence or a word, and their eye movements are recorded using an eye tracker. Eye tracking data provides a sensitive measure in the VWP to investigate a wide range of psycholinguistic research questions. By analyzing eye movement patterns, researchers can, for example, infer which object participants are attending to during language processing, and they can investigate how gaze patterns change over time. A concrete example will follow shortly. The VWP is suitable for studying language comprehension and production among individuals of all ages and diverse populations, including those with special needs (Salverda & Tanenhaus, 2017).

Between different VWP studies, the content and structure of the visual and auditory stimuli might be different, but most VWP experiments follow similar design principles (see picture 3). Every trial consists of several visual objects presented simultaneously and accompanied by an audio file. The audio instructions can be as diverse as the selected visual objects, ranging from single words to questions or instructions. Picture 4 shows a concrete example of the VWP based on Altmann and Kamide (1999). Participants will, for example, hear the sentence “The boy will eat the cake” or “the boy will move the cake”. In the first case, the cake constitutes the target object, whereas all other objects are so-called distractors. The verb ‘eat’ should allow the listener to anticipate that ‘cake’ will be said as only the cake can be eaten. As a result, they start looking at the cake before it is even mentioned. In the latter case, all other objects are so-called competitors because all objects can be moved.  

The VWP is not only a prime example of how eye tracking technology can be used to get insights into cognitive processes. It also serves as an excellent demonstration of a paradigm that can easily be implemented using the ASP. Manually creating the stimuli of a VWP, considering all possible experimental conditions, can be a tedious and time-consuming process as hundreds of stimuli might need to be created. Designing the experiment in a spreadsheet containing all the information that Tobii Pro Lab will refer to enables complex designs with many multi-image stimuli, such as the VWP, and gives researchers better control over the workflow, saving valuable time and reducing the risk of design mistakes.

Explore the features in Tobii Pro Lab to design and analyze a visual world paradigm. Watch our demo walkthrough and download the sample project.

Summary

The ASP is a powerful tool for designing and conducting complex, screen-based eye tracking studies, such as the VWP, inter-modal preferential looking and PL studies. Setting up experiments in a spreadsheet format makes it possible to conduct experiments with many stimuli or even create multi-image stimuli. The ASP currently supports image and audio files, but more will be added in the future. Together with the infant calibration routine in Tobii Pro Lab, the ASP is an ideal tool for infant research in cognitive psychology and linguistics. You can learn more about the ASP in our Tobii Academy module and check out the demo projects on PF and VWP.

Cited publications

Altmann, G. T. M., & Kamide, Y. (1999). Incremental interpretation at verbs: Restricting the domain of subsequent reference. Cognition, 73, 247-264.

Cooper, R.M. (1974). The control of eye fixation by the meaning of spoken language: A new methodology for the real-time investigation of speech perception, memory, and language processing. Cognitive Psychology, 6, 84-107.

Fernald, A., Pinto, J.P., Swingley, D., Weinberg, A., & McRoberts, G.W. (1998). Rapid gains in speed of verbal processing by infants in the 2nd year. Psychological Science, 9(3), 228-231.

Salverda, A.P., Tanenhaus, M.K. (2017). The visual world paradigm. Research Methods in Psycholinguistics and the Neurobiology of Language: A Practical Guide, 9, 89-110.

Tanenhaus, M. K., Spivey-Knowlton, M. J., Eberhard, K. M., & Sedivy, J. C. (1995). Integration of visual and linguistic information in spoken language comprehension. Science, 268(5217), 1632-1634.

Quinn, P. C., & Eimas, P. D. (1996). Perceptual cues that permit categorical differentiation of animal species by infants. Journal of Experimental Child Psychology, 63(2), 189-211.