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11:00 - 12:30
Parallel sessions 8
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11:00 - 12:30
Room: HSZ - N1
Chair/s:
Philine Margarete Baumert, Celina Kullmann
Oculomotor research has a long tradition in experimental psychology. In humans, visual input provides the highest amount of information per time in comparison to other senses, and about 50% of the neocortex reacts to visual stimuli. With today’s technology, eye movements are easy to access, do not rely on participants’ subjective reports, and usually do not require complicated task instructions. Their neural basis, both neurochemical and neurophysiological, has been studied extensively. Therefore, they can provide insights into health and disease, numerous aspects of cognition, and can be viewed as an estimate of brain functioning. Despite the field’s long history, new methods and technologies open up new possibilities and questions, as well as new pathways to solving well-known problems. Here, we aim to present current methods, approaches, and directions in the field of oculomotor research in experimental psychology. First, Celina Kullmann will introduce the method of latent state-trait modelling and resulting reliability as well as trait and state components of smooth pursuit eye movements. Next, Paul Schmitthäuser will speak on how a new experimental paradigm makes use of saccadic inhibition to assess oculomotor planning and attentional priority. Keaton Dahl will contribute new insights into fixational eye movements and how specific statistical methods can be applied to them in face recognition tasks. Then, Philine Baumert will present findings on how lorazepam influences microsaccades during fixational and exploratory gaze behavior. As a final contribution, Alexander Goettker will shed light on the statistics of natural gaze behavior using mobile recordings and how they compare to laboratory-gained estimates. Overall, the symposium will demonstrate new perspectives as well as recent progress in exciting areas of oculomotor research, underscoring its continued relevance to the field of experimental psychology.
Submission 638
Saccadic Inhibition as a Window into Perceptual and Oculomotor Dynamics
SymposiumTalk-02
Presented by: Paul Schmitthäuser
Paul Schmitthäuser 1, 2, Martin Rolfs 1, Nina M. Hanning 1
1 Humboldt-University, Berlin, Germany
2 Free University of Berlin, Germany
We produce saccadic eye movements at a baseline rate of approximately 2 to 4 per second. Sudden visual transients lead to a rapid reduction in the saccade rate, known as “saccadic inhibition”. While traditionally studied as a phenomenon of motor interruption, this reflexive response can be exploited as a continuous measurement tool of visual sensitivity and thus give access to attentional dynamics in active vision. As such, it is well-suited to current developments in oculomotor research that emphasize ecological validity and methodological innovation.

Here, we introduce a free-viewing paradigm that leverages saccadic inhibition to map spatial patterns of attentional priority and oculomotor planning during unrestricted, self-paced visual exploration. Participants search an array of differently colored tiles for a hidden target under time pressure. Because tile colors signal different target likelihoods, observers adopt systematic search strategies that enable predictions of gaze behavior. During ongoing search, brief probes are presented at controlled distances relative to the current and expected future fixation positions that reliably induce saccadic inhibition. We show that systematic variations in this response provide a moment-by-moment, response-free estimate of attentional and motor priority across the visual field.

By turning a well-characterized oculomotor reflex into a flexible measurement tool, this approach promises a pathway for studying the dynamics of attention in natural vision. Critically, it does not rely on explicit judgments, elaborate task instructions, or disruption of natural gaze behavior, making it amenable to populations for whom explicit responses or complex tasks are challenging.