13:30 - 15:00
Mon-A6-Talk II-
Mon-Talk II-
Room: A6
Chair/s:
Simon Merz
Spatial changes of an object over time are usually perceived as motion. Over the years, various perceptual errors have been identified for dynamic, moving objects. These include, but are not limited to, spatial over- or underestimation of the initial or final position (e.g. Fröhlich Effect, Onset-Repulsion Effect, Representational-Momentum Effect, Offset-Repulsion Effect), spatio-temporal discrepancies between moving and stationary objects (Flash-Lag Effect, Flash-Drag Effect) or the interaction between spatial and temporal properties of a dynamic display (e.g. Kappa Effect, Tau Effect). Given the vast amount of different perceptual errors reported over the decades, many theoretical explanations have been proposed. With the common goal of understanding spatio-temporal perception of dynamic objects, the symposium aims to bring together researchers working on the different perceptual biases to enable cross-paradigm perspectives and discussion. The speakers will present experimental work using different experimental procedures, analytical approaches and theoretical background to show current developments in the field, with the final talk in the session allowing general, talk overarching discussions about human spatio-temporal perception and the possible mechanisms underlying these processes.
Speeding up (and down) expectations: Investigating the influence of experimental context on speed perception
Mon-A6-Talk II-01
Presented by: Simon Merz
Simon Merz 1, Charles Spence 2, Christian Frings 1
1 University of Trier, 2 University of Oxford
Motion perception is prone to systematic biases. For example, when asked to localize the onset or offset of a dynamic, moving target, perceptual shifts in, as well as against motion direction can be systematically observed, the so called Fröhlich effect, Onset repulsion effect, Representational Momentum effect, and Offset repulsion effect. Following new theoretical developments, one crucial underlying factor for these localization biases should be expectations regarding stimulus speed. In order to test this prediction, perceptually identical target motion trials are presented and compared across different experimental context. In these experimental contexts, different speed characteristics are realized, eliciting different speed expectations. The data indicate an effect of experimental context on the localization of dynamic stimuli, and implications for future theoretical developments and current theoretical formulations are discussed.
Keywords: motion perception, speed expectations, localization, Fröhlich effect, Representational Momentum