Dynamic combination of position and motion information when tracking moving targets

Abstract

To accurately foveate a moving target, the oculomotor system needs to estimate the position of the target at the saccade end, based on information about its position and ongoing movement, while accounting for neuronal delays and execution time of the saccade. We investigated human interceptive saccades and pursuit responses to moving targets defined by high and low luminance contrast or by chromatic contrast only (isoluminance). We used step-ramps with perpendicular directions between vertical target steps of 10 deg/s and horizontal ramps of 2.5 to 20 deg/s to separate errors with respect to the position step of the target in the vertical dimension, and errors related to target motion in the horizontal dimension. Interceptive saccades to targets of high and low luminance contrast landed close to the actual target positions, suggesting relatively accurate estimates of the amount of target displacement. Interceptive saccades to isoluminant targets were less accurate. They landed at positions the target had on average 100 ms before saccade onset. One account of this finding is that the integration of target motion is compromised for isoluminant targets moving in the periphery. In this case, the oculomotor system can use an accurate, but delayed position component, but cannot account for target movement. This deficit was also present for the postsaccadic pursuit speed. For the two luminance conditions, pursuit direction and speed were adjusted depending on the saccadic landing position. The rapid postsaccadic pursuit adjustments suggest shared position-and motion-related signals of target and eye for saccade and pursuit control.

Retinal error signals and fluctuations in eye velocity influence oculomotor behavior in subsequent trials

“…Due to the ball's movement and our inherent processing delays, the ball will already be at a different position than where it was when the planning of eye movement started. It has been shown before that saccadic ( Keller & Johnson, 1990 ; Gellman & Carl, 1991 ; Engel, Kevin, Anderson & Soechting, 1999 ; Guan, Eggert, Bayer & Büttner, 2005 ; Schreiber, Missal & Lefèvre, 2006 ; Fleuriet, Hugues, Perrinet & Goffart, 2010 ; Daye, Blohm & Lefèvre, 2014 ; Goettker, Braun & Gegenfurtner, 2019 ) and smooth pursuit eye movements ( Bahill & McDonald, 1983 ; Orban de Xivry, Bennett, Lefèvre & Barnes, 2006 ) can successfully account for target movements and processing delays by using the currently available sensory information to estimate correct target positions at the end of eye movements.…”

From Gaussian blobs to naturalistic videos: Comparison of oculomotor behavior across different stimulus complexities

“…This benefit cannot be explained by the orientation of the saccade ( Figure 3 E), leaving an explanation based on early interactions between the saccadic and pursuit system, as recently shown by Goettker and colleagues (2019). If the last part of the saccade is already affected by the upcoming pursuit response, saccade endpoints will deviate based on the upcoming pursuit direction, which will then increase the position error for the landing position, thus suggesting that saccades and pursuit are based on shared signals ( Deravet et al, 2018 ; Erkelens, 2006 ; Goettker et al, 2019 ; Hainque, Apartis, & Daye, 2016 ; Orban de Xivry & Lefèvre, 2007 ), which optimize the tracking performance at the transition between saccades and pursuit.…”

“…Moving stimuli typically elicit an initial interceptive saccade followed by smooth pursuit, allowing us to study both types of eye movement responses at the same time. Additionally, we tried to look into potential interactions between the saccadic and pursuit eye movements (Goettker et al, 2019;Orban de Xivry & Lefèvre, 2007) by manipulating the relative angle between the two. The goal of our study was to bridge the gap between studying oculomotor behavior with very simple stimuli and in response to naturalistic videos.…”

“…Single-unit recordings, behavioral investigations, computational modeling, and the combination of these three approaches have led to tremendous advances in our understanding of oculomotor control (for reviews, see Lisberger, 2015 ; Robinson, 1981 ; Sommer & Wurtz, 2008 ; Sparks & Mays, 1990 ). For example, synthetic and controlled stimuli have been used to study the role of stimulus characteristics such as contrast ( Doma & Hallett, 1988 ; Ludwig, Gilchrist, & McSorley, 2004 ), movement of a stimulus ( de Brouwer, Missal, Barnes, & Lefèvre, 2002 ; Goettker, Braun, & Gegenfurtner, 2019 ; Schreiber, Missal, & Lefèvre, 2006 ), or even cognitive and decision-making processes (for reviews, see Glimcher, 2003 ; Munoz & Everling, 2004 ). In addition, the controlled settings allow isolating the effect of stimulus characteristics on different oculomotor behaviors, including the effect of target contrast on saccade control ( Doma & Hallett, 1988 ; Ludwig et al, 2004 ) or its effect on pursuit eye movements ( Haegerstrom-Portnoy & Brown, 1979 ; O'Mullane & Knox, 1999 ).…”

Introduction to special issue on “Prediction in Perception and Action”

“…For example, a predictive component is necessary for the smooth coordination of pursuit and saccades. Goettker et al (2019) show that the pursuit and saccadic system share a common internal representation of the target movement and interact closely to improve tracking responses rapidly. Congruently, Kwon et al (2019) show that the integration of position and motion information extends to the ocular following response.…”