11:00 - 12:30
Parallel sessions 8
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 416
GABAergic Modulation of Microsaccades in Sustained Fixation and Free Viewing
SymposiumTalk-04
Presented by: Philine Baumert
Philine Baumert 1, Wolf Harmening 2, Maximilian Wintergerst 2, 4, Jan Terheyden 2, Behrem Aslan 3, Ulrich Ettinger 1, Kaja Faßbender 1
1 Department of Psychology, University of Bonn, Germany
2 Department of Ophthalmology, University Hospital Bonn, Germany
3 Department of Psychiatry and Psychotherapy, University Hospital Bonn, Germany
4 Augenzentrum Grischun, Chur, Switzerland
Modulation of gamma-aminobutyric-acid (GABA) A receptor activity via benzodiazepine administration has been consistently found to reduce saccadic peak velocity. While microsaccades are considered part of the fixational eye movement repertoire, their underlying neurophysiology has been hypothesised to resemble that of large saccades. Whether changes to GABAergic receptor activity affect microsaccades in the same way they do large saccades has not yet been investigated in humans. This study’s aim was to examine whether the established effect of benzodiazepine administration on saccadic peak velocity could be observed in microsaccades. It was further explored whether this might be task-dependent. Thirty healthy adults were administered either 1mg lorazepam or placebo in a randomised, double-blind, within-subjects design. As microsaccades have been shown to vary in purpose and frequency in a highly task-dependent manner, they were assessed in a sustained fixation task as well as a free viewing task. Lorazepam in comparison to placebo led to a decrease in microsaccadic peak velocity in both tasks. It additionally increased microsaccadic frequency and amplitude during sustained fixation but not during free viewing. Overall, our findings confirm the sublime sensitivity of saccadic peak velocity to modulation of GABA A receptor activity via benzodiazepine administration. Notably, this is the first study to expand this finding to microsaccades. Implications for the neurophysiology of microsaccades as well as for their task-dependent purposes are discussed.