1
|
Coudiere A, Danion FR. Eye-hand coordination all the way: from discrete to continuous hand movements. J Neurophysiol 2024; 131:652-667. [PMID: 38381528 DOI: 10.1152/jn.00314.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 01/31/2024] [Accepted: 02/18/2024] [Indexed: 02/23/2024] Open
Abstract
The differentiation between continuous and discrete actions is key for behavioral neuroscience. Although many studies have characterized eye-hand coordination during discrete (e.g., reaching) and continuous (e.g., pursuit tracking) actions, all these studies were conducted separately, using different setups and participants. In addition, how eye-hand coordination might operate at the frontier between discrete and continuous movements remains unexplored. Here we filled these gaps by means of a task that could elicit different movement dynamics. Twenty-eight participants were asked to simultaneously track with their eyes and a joystick a visual target that followed an unpredictable trajectory and whose position was updated at different rates (from 1.5 to 240 Hz). This procedure allowed us to examine actions ranging from discrete point-to-point movements (low refresh rate) to continuous pursuit (high refresh rate). For comparison, we also tested a manual tracking condition with the eyes fixed and a pure eye tracking condition (hand fixed). The results showed an abrupt transition between discrete and continuous hand movements around 3 Hz contrasting with a smooth trade-off between fixations and smooth pursuit. Nevertheless, hand and eye tracking accuracy remained strongly correlated, with each of these depending on whether the other effector was recruited. Moreover, gaze-cursor distance and lag were smaller when eye and hand performed the task conjointly than separately. Altogether, despite some dissimilarities in eye and hand dynamics when transitioning between discrete and continuous movements, our results emphasize that eye-hand coordination continues to smoothly operate and support the notion of synergies across eye movement types.NEW & NOTEWORTHY The differentiation between continuous and discrete actions is key for behavioral neuroscience. By using a visuomotor task in which we manipulate the target refresh rate to trigger different movement dynamics, we explored eye-hand coordination all the way from discrete to continuous actions. Despite abrupt changes in hand dynamics, eye-hand coordination continues to operate via a gradual trade-off between fixations and smooth pursuit, an observation confirming the notion of synergies across eye movement types.
Collapse
Affiliation(s)
- Adrien Coudiere
- CNRS, Université de Poitiers, Université de Tours, CeRCA, Poitiers, France
| | - Frederic R Danion
- CNRS, Université de Poitiers, Université de Tours, CeRCA, Poitiers, France
| |
Collapse
|
2
|
Hirata T, Hirata Y, Kawai N. Human estimates of descending objects' motion are more accurate than those of ascending objects regardless of gravity information. J Vis 2024; 24:2. [PMID: 38436983 PMCID: PMC10913939 DOI: 10.1167/jov.24.3.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 12/27/2023] [Indexed: 03/05/2024] Open
Abstract
Humans can accurately estimate and track object motion, even if it accelerates. Research shows that humans exhibit superior estimation and tracking performance for descending (falling) than ascending (rising) objects. Previous studies presented ascending and descending targets along the gravitational and body axes in an upright posture. Thus, it is unclear whether humans rely on congruent information between the direction of the target motion and gravity or the direction of the target motion and longitudinal body axes. Two experiments were conducted to explore these possibilities. In Experiment 1, participants estimated the arrival time at a goal for both upward and downward motion of targets along the longitudinal body axis in the upright (both axes of target motion and gravity congruent) and supine (both axes incongruent) postures. In Experiment 2, smooth pursuit eye movements were assessed while tracking both targets in the same postures. Arrival time estimation and smooth pursuit eye movement performance were consistently more accurate for downward target motion than for upward motion, irrespective of posture. These findings suggest that the visual experience of seeing an object moving along an observer's leg side in everyday life may influence the ability to accurately estimate and track the descending object's motion.
Collapse
Affiliation(s)
- Takashi Hirata
- Department of Cognitive and Psychological Sciences, Nagoya University Graduate School of Informatics, Nagoya, Aichi, Japan
- JSPS Research Fellowships for Young Scientists, Tokyo, Japan
| | - Yutaka Hirata
- Department of Artificial Intelligence and Robotics, Chubu University College of Science and Engineering, Kasugai, Aichi, Japan
- Academy of Emerging Sciences, Chubu University, Kasugai, Aichi, Japan
- Center for Mathematical Science and Artificial Intelligence, Chubu University, Kasugai, Aichi, Japan
| | - Nobuyuki Kawai
- Department of Cognitive and Psychological Sciences, Nagoya University Graduate School of Informatics, Nagoya, Aichi, Japan
- Academy of Emerging Sciences, Chubu University, Kasugai, Aichi, Japan
| |
Collapse
|
3
|
Nakazato R, Aoyama C, Komiyama T, Himo R, Shimegi S. Table tennis players use superior saccadic eye movements to track moving visual targets. Front Sports Act Living 2024; 6:1289800. [PMID: 38406764 PMCID: PMC10884183 DOI: 10.3389/fspor.2024.1289800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/24/2024] [Indexed: 02/27/2024] Open
Abstract
Introduction Table tennis players perform visually guided visuomotor responses countlessly. The exposure of the visual system to frequent and long-term motion stimulation has been known to improve perceptual motion detection and discrimination abilities as a learning effect specific to that stimulus, so may also improve visuo-oculomotor performance. We hypothesized and verified that table tennis players have good spatial accuracy of saccades to moving targets. Methods University table tennis players (TT group) and control participants with no striking-sports experience (Control group) wore a virtual reality headset and performed two ball-tracking tasks to track moving and stationary targets in virtual reality. The ball moved from a predetermined position on the opponent's court toward the participant's court. A total of 54 conditions were examined for the moving targets in combinations of three ball trajectories (familiar parabolic, unfamiliar descent, and unfamiliar horizontal), three courses (left, right, and center), and six speeds. Results and discussion All participants primarily used catch-up saccades to track the moving ball. The TT group had lower mean and inter-trial variability in saccade endpoint error compared to the Control group, showing higher spatial accuracy and precision, respectively. It suggests their improvement of the ability to analyze the direction and speed of the ball's movement and predict its trajectory and future destination. The superiority of the spatial accuracy in the TT group was seen in both the right and the left courses for all trajectories but that of precision was for familiar parabolic only. The trajectory dependence of improved saccade precision in the TT group implies the possibility that the motion vision system is trained by the visual stimuli frequently encountered in table tennis. There was no difference between the two groups in the onset time or spatial accuracy of saccades for stationary targets appearing at various positions on the ping-pong table. Conclusion Table tennis players can obtain high performance (spatial accuracy and precision) of saccades to track moving targets as a result of motion vision ability improved through a vast amount of visual and visuo-ocular experience in their play.
Collapse
Affiliation(s)
- Riku Nakazato
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka, Japan
| | - Chisa Aoyama
- Graduate School of Medicine, Osaka University, Toyonaka, Osaka, Japan
| | - Takaaki Komiyama
- Center for Education in Liberal Arts and Sciences, Osaka University, Toyonaka, Osaka, Japan
| | - Ryoto Himo
- Faculty of Science, Osaka University, Toyonaka, Osaka, Japan
| | - Satoshi Shimegi
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka, Japan
- Center for Education in Liberal Arts and Sciences, Osaka University, Toyonaka, Osaka, Japan
| |
Collapse
|
4
|
D'Aquino A, Frank C, Hagan JE, Schack T. Eye movements during motor imagery and execution reveal different visuomotor control strategies in manual interception. Psychophysiology 2023; 60:e14401. [PMID: 37515410 DOI: 10.1111/psyp.14401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 07/06/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023]
Abstract
Previous research has investigated the degree of congruency in gaze metrics between action execution (AE) and motor imagery (MI) for similar manual tasks. Although eye movement dynamics seem to be limited to relatively simple actions toward static objects, there is little evidence of how gaze parameters change during imagery as a function of more dynamic spatial and temporal task demands. This study examined the similarities and differences in eye movements during AE and MI for an interception task. Twenty-four students were asked to either mentally simulate or physically intercept a moving target on a computer display. Smooth pursuit, saccades, and response time were compared between the two conditions. The results show that MI was characterized by higher smooth pursuit gain and duration while no meaningful differences were found in the other parameters. The findings indicate that eye movements during imagery are not simply a duplicate of what happens during actual performance. Instead, eye movements appear to vary as a function of the interaction between visuomotor control strategies and task demands.
Collapse
Affiliation(s)
- Alessio D'Aquino
- Neurocognition and Action Biomechanics Group, Faculty of Psychology and Sports Science, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - Cornelia Frank
- Institute for Sport and Movement Science, Osnabrück University, Osnabrück, Germany
| | - John Elvis Hagan
- Neurocognition and Action Biomechanics Group, Faculty of Psychology and Sports Science, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - Thomas Schack
- Neurocognition and Action Biomechanics Group, Faculty of Psychology and Sports Science, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
- Research Institute for Cognition and Robotics (CoR-Lab), Bielefeld University, Bielefeld, Germany
| |
Collapse
|
5
|
de la Malla C, Goettker A. The effect of impaired velocity signals on goal-directed eye and hand movements. Sci Rep 2023; 13:13646. [PMID: 37607970 PMCID: PMC10444871 DOI: 10.1038/s41598-023-40394-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 08/09/2023] [Indexed: 08/24/2023] Open
Abstract
Information about position and velocity is essential to predict where moving targets will be in the future, and to accurately move towards them. But how are the two signals combined over time to complete goal-directed movements? We show that when velocity information is impaired due to using second-order motion stimuli, saccades directed towards moving targets land at positions where targets were ~ 100 ms before saccade initiation, but hand movements are accurate. Importantly, the longer latencies of hand movements allow for additional time to process the sensory information available. When increasing the period of time one sees the moving target before making the saccade, saccades become accurate. In line with that, hand movements with short latencies show higher curvature, indicating corrections based on an update of incoming sensory information. These results suggest that movements are controlled by an independent and evolving combination of sensory information about the target's position and velocity.
Collapse
Affiliation(s)
- Cristina de la Malla
- Vision and Control of Action Group, Department of Cognition, Development, and Psychology of Education, Institute of Neurosciences, Universitat de Barcelona, Barcelona, Catalonia, Spain.
| | - Alexander Goettker
- Justus Liebig Universität Giessen, Giessen, Germany.
- Center for Mind, Brain and Behavior, University of Marburg and Justus Liebig University, Giessen, Germany.
| |
Collapse
|
6
|
Reschechtko S, Gnanaseelan C, Pruszynski JA. Reach Corrections Toward Moving Objects are Faster Than Reach Corrections Toward Instantaneously Switching Targets. Neuroscience 2023; 526:135-143. [PMID: 37391122 DOI: 10.1016/j.neuroscience.2023.06.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 07/02/2023]
Abstract
Visually guided reaching is a common motor behavior that engages subcortical circuits to mediate rapid corrections. Although these neural mechanisms have evolved for interacting with the physical world, they are often studied in the context of reaching toward virtual targets on a screen. These targets often change position by disappearing from one place reappearing in another instantaneously. In this study, we instructed participants to perform rapid reaches to physical objects that changed position in different ways. In one condition, the objects moved very rapidly from one place to another. In the other condition, illuminated targets instantaneously switched position by being extinguished in one position and illuminating in another. Participants were consistently faster in correcting their reach trajectories when the object moved continuously.
Collapse
Affiliation(s)
- Sasha Reschechtko
- School of Exercise & Nutritional Sciences, San Diego State University, 351 ENS Building, 5500 Campanile Dr., San Diego, CA 92182, USA; Western BrainsCAN, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada; Brain and Mind Institute, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada; Robarts Research Institute, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada; Department of Physiology & Pharmacology, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada.
| | - Cynthiya Gnanaseelan
- Department of Physiology & Pharmacology, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada
| | - J Andrew Pruszynski
- Brain and Mind Institute, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada; Robarts Research Institute, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada; Department of Physiology & Pharmacology, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada; Department of Psychology, Western University, 1151 Richmond St., London, ON N6A 3K7, Canada
| |
Collapse
|
7
|
Gómez-Granados A, Kurtzer I, Gordon S, Barany DA, Singh T. Object motion influences feedforward motor responses during mechanical stopping of virtual projectiles: a preliminary study. Exp Brain Res 2023; 241:1077-1087. [PMID: 36869269 DOI: 10.1007/s00221-023-06576-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/16/2023] [Indexed: 03/05/2023]
Abstract
An important window into sensorimotor function is how humans interact and stop moving projectiles, such as stopping a door from closing shut or catching a ball. Previous studies have suggested that humans time the initiation and modulate the amplitude of their muscle activity based on the momentum of the approaching object. However, real-world experiments are constrained by laws of mechanics, which cannot be manipulated experimentally to probe the mechanisms of sensorimotor control and learning. An augmented-reality variant of such tasks allows for experimental manipulation of the relationship between motion and force to obtain novel insights into how the nervous system prepares motor responses to interact with moving stimuli. Existing paradigms for studying interactions with moving projectiles use massless objects and are primarily focused on quantifying gaze and hand kinematics. Here, we developed a novel collision paradigm using a robotic manipulandum where participants mechanically stopped a virtual object moving in the horizontal plane. On each block of trials, we varied the virtual object's momentum by increasing either its velocity or mass. Participants stopped the object by applying a force impulse that matched the object momentum. We observed that hand force increased as a function of object momentum linked to changes in virtual mass or velocity, similar to results from studies involving catching free-falling objects. In addition, increasing object velocity resulted in later onset of hand force relative to the impending time-to-contact. These findings show that the present paradigm can be used to determine how humans process projectile motion for hand motor control.
Collapse
Affiliation(s)
- Ana Gómez-Granados
- Department of Kinesiology, University of Georgia, Athens, GA, 30602, USA
| | - Isaac Kurtzer
- Department of Biomedical Science, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, NY, 11568, USA
| | - Sean Gordon
- Department of Kinesiology, University of Georgia, Athens, GA, 30602, USA
| | - Deborah A Barany
- Department of Kinesiology, University of Georgia, Athens, GA, 30602, USA
- Augusta University/University of Georgia Medical Partnership, Athens, GA, 30602, USA
| | - Tarkeshwar Singh
- Department of Kinesiology, The Pennsylvania State University, 32 Recreation Building, University Park, PA, 16802, USA.
| |
Collapse
|
8
|
Gonzalez Polanco P, Mrotek LA, Nielson KA, Beardsley SA, Scheidt RA. When intercepting moving targets, mid-movement error corrections reflect distinct responses to visual and haptic perturbations. Exp Brain Res 2023; 241:231-247. [PMID: 36469052 PMCID: PMC10440829 DOI: 10.1007/s00221-022-06515-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 11/20/2022] [Indexed: 12/09/2022]
Abstract
We examined a key aspect of sensorimotor skill: the capability to correct performance errors that arise mid-movement. Participants grasped the handle of a robot that imposed a nominal viscous resistance to hand movement. They watched a target move pseudo-randomly just above the horizontal plane of hand motion and initiated quick interception movements when cued. On some trials, the robot's viscosity or the target's speed changed without warning coincident with the GO cue. We fit a sum-of-Gaussians model to mechanical power measured at the handle to determine the number, magnitude, and relative timing of submovements occurring in each interception attempt. When a single submovement successfully intercepted the target, capture times averaged 410 ms. Sometimes, two or more submovements were required. Initial error corrections typically occurred before feedback could indicate the target had been captured or missed. Error corrections occurred sooner after movement onset in response to mechanical viscosity increases (at 154 ms) than to unprovoked errors on control trials (215 ms). Corrections occurred later (272 ms) in response to viscosity decreases. The latency of corrections for target speed changes did not differ from those in control trials. Remarkably, these early error corrections accommodated the altered testing conditions; speed/viscosity increases elicited more vigorous corrections than in control trials with unprovoked errors; speed/viscosity decreases elicited less vigorous corrections. These results suggest that the brain monitors and predicts the outcome of evolving movements, rapidly infers causes of mid-movement errors, and plans and executes corrections-all within 300 ms of movement onset.
Collapse
Affiliation(s)
- Pablo Gonzalez Polanco
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA
| | - Leigh A Mrotek
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA
| | - Kristy A Nielson
- Psychology, Marquette University and Neurology, Medical College of Wisconsin, Milwaukee, WI, 53233, USA
| | - Scott A Beardsley
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA
| | - Robert A Scheidt
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA.
| |
Collapse
|
9
|
de la Malla C, Smeets JBJ, Brenner E. Pursuing a target with one's eyes helps judge its velocity. Perception 2022; 51:919-922. [DOI: 10.1177/03010066221133324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
When intercepting moving targets, people perform slightly better if they follow their natural tendency to pursue the target with their eyes. Is this because the velocity is judged more precisely when pursuing the target? To find out, we compared how well people could determine which of two sequentially presented moving bars was moving faster. There was always also a static bar on the screen. People judged the moving bar's velocity about 10% more precisely when pursuing it than when fixating the static bar.
Collapse
Affiliation(s)
| | | | - Eli Brenner
- Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
10
|
Manzone DM, Tremblay L, Chua R. Tactile facilitation during actual and mere expectation of object reception. Sci Rep 2022; 12:17514. [PMID: 36266418 PMCID: PMC9585022 DOI: 10.1038/s41598-022-22133-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/10/2022] [Indexed: 01/12/2023] Open
Abstract
During reaching and grasping movements tactile processing is typically suppressed. However, during a reception or catching task, the object can still be acquired but without suppressive processes related to movement execution. Rather, tactile information may be facilitated as the object approaches in anticipation of object contact and the utilization of tactile feedback. Therefore, the current study investigated tactile processing during a reception task. Participants sat with their upper limb still as an object travelled to and contacted their fingers. At different points along the object's trajectory and prior to contact, participants were asked to detect tactile stimuli delivered to their index finger. To understand if the expectation of object contact contributed to any modulation in tactile processing, the object stopped prematurely on 20% of trials. Compared to a pre-object movement baseline, relative perceptual thresholds were decreased throughout the object's trajectory, and even when the object stopped prematurely. Further, there was no evidence for modulation when the stimulus was presented shortly before object contact. The former results suggest that tactile processing is facilitated as an object approaches an individual's hand. As well, we purport that the expectation of tactile feedback drives this modulation. Finally, the latter results suggest that peripheral masking may have reduced/abolished any facilitation.
Collapse
Affiliation(s)
- Damian M. Manzone
- grid.17063.330000 0001 2157 2938Perceptual Motor Behaviour Laboratory, Centre for Motor Control, Faculty of Kinesiology and Physical Education, University of Toronto, 55 Harbord Street, Toronto, ON M5S 2W6 Canada
| | - Luc Tremblay
- grid.17063.330000 0001 2157 2938Perceptual Motor Behaviour Laboratory, Centre for Motor Control, Faculty of Kinesiology and Physical Education, University of Toronto, 55 Harbord Street, Toronto, ON M5S 2W6 Canada
| | - Romeo Chua
- grid.17091.3e0000 0001 2288 9830School of Kinesiology, University of British Columbia, Vancouver, BC Canada
| |
Collapse
|
11
|
Vater C, Mann DL. Are predictive saccades linked to the processing of peripheral information? PSYCHOLOGICAL RESEARCH 2022; 87:1501-1519. [PMID: 36167931 DOI: 10.1007/s00426-022-01743-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/15/2022] [Indexed: 11/29/2022]
Abstract
High-level athletes can predict the actions of an opposing player. Interestingly, such predictions are also reflected by the athlete's gaze behavior. In cricket, for example, players first pursue the ball with their eyes before they very often initiate two predictive saccades: one to the predicted ball-bounce point and a second to the predicted ball-bat-contact point. That means, they move their eyes ahead of the ball and "wait" for the ball at the new fixation location, potentially using their peripheral vision to update information about the ball's trajectory. In this study, we investigated whether predictive saccades are linked to the processing of information in peripheral vision and if predictive saccades are superior to continuously following the ball with foveal vision using smooth-pursuit eye-movements (SPEMs). In the first two experiments, we evoked the typical eye-movements observed in cricket and showed that the information gathered during SPEMs is sufficient to predict when the moving object will hit the target location and that (additional) peripheral monitoring of the object does not help to improve performance. In a third experiment, we show that it could actually be beneficial to use SPEMs rather than predictive saccades to improve performance. Thus, predictive saccades ahead of a target are unlikely to be performed to enhance the peripheral monitoring of target.
Collapse
Affiliation(s)
- Christian Vater
- Institute of Sport Science, University of Bern, Bremgartenstrasse 145, 3012, Bern, Switzerland.
| | - David L Mann
- Faculty of Behavioural and Movement Sciences, Motor Learning and Performance, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
12
|
D'Aquino A, Frank C, Hagan JE, Schack T. Imagining interceptions: Eye movements as an online indicator of covert motor processes during motor imagery. Front Neurosci 2022; 16:940772. [PMID: 35968367 PMCID: PMC9372347 DOI: 10.3389/fnins.2022.940772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/13/2022] [Indexed: 11/21/2022] Open
Abstract
The analysis of eye movements during motor imagery has been used to understand the influence of covert motor processes on visual-perceptual activity. There is evidence showing that gaze metrics seem to be affected by motor planning often dependent on the spatial and temporal characteristics of a task. However, previous research has focused on simulated actions toward static targets with limited empirical evidence of how eye movements change in more dynamic environments. The study examined the characteristics of eye movements during motor imagery for an interception task. Twenty-four participants were asked to track a moving target over a computer display and either mentally simulate an interception or rest. The results showed that smooth pursuit variables, such as duration and gain, were lower during motor imagery when compared to passive observation. These findings indicate that motor plans integrate visual-perceptual information based on task demands and that eye movements during imagery reflect such constraint.
Collapse
Affiliation(s)
- Alessio D'Aquino
- Faculty of Psychology and Sports Science, Neurocognition and Action Biomechanics Group, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - Cornelia Frank
- Institute for Sport and Movement Science, Osnabrück University, Osnabrück, Germany
| | - John Elvis Hagan
- Faculty of Psychology and Sports Science, Neurocognition and Action Biomechanics Group, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - Thomas Schack
- Faculty of Psychology and Sports Science, Neurocognition and Action Biomechanics Group, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
- Research Institute for Cognition and Robotics (CoR-Lab), Bielefeld University, Bielefeld, Germany
| |
Collapse
|
13
|
Aguado B, López-Moliner J. Gravity and Known Size Calibrate Visual Information to Time Parabolic Trajectories. Front Hum Neurosci 2021; 15:642025. [PMID: 34497497 PMCID: PMC8420811 DOI: 10.3389/fnhum.2021.642025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 07/28/2021] [Indexed: 11/13/2022] Open
Abstract
Catching a ball in a parabolic flight is a complex task in which the time and area of interception are strongly coupled, making interception possible for a short period. Although this makes the estimation of time-to-contact (TTC) from visual information in parabolic trajectories very useful, previous attempts to explain our precision in interceptive tasks circumvent the need to estimate TTC to guide our action. Obtaining TTC from optical variables alone in parabolic trajectories would imply very complex transformations from 2D retinal images to a 3D layout. We propose based on previous work and show by using simulations that exploiting prior distributions of gravity and known physical size makes these transformations much simpler, enabling predictive capacities from minimal early visual information. Optical information is inherently ambiguous, and therefore, it is necessary to explain how these prior distributions generate predictions. Here is where the role of prior information comes into play: it could help to interpret and calibrate visual information to yield meaningful predictions of the remaining TTC. The objective of this work is: (1) to describe the primary sources of information available to the observer in parabolic trajectories; (2) unveil how prior information can be used to disambiguate the sources of visual information within a Bayesian encoding-decoding framework; (3) show that such predictions might be robust against complex dynamic environments; and (4) indicate future lines of research to scrutinize the role of prior knowledge calibrating visual information and prediction for action control.
Collapse
Affiliation(s)
- Borja Aguado
- Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Joan López-Moliner
- Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
14
|
Goettker A, Gegenfurtner KR. A change in perspective: The interaction of saccadic and pursuit eye movements in oculomotor control and perception. Vision Res 2021; 188:283-296. [PMID: 34489101 DOI: 10.1016/j.visres.2021.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/26/2021] [Accepted: 08/16/2021] [Indexed: 11/17/2022]
Abstract
Due to the close relationship between oculomotor behavior and visual processing, eye movements have been studied in many different areas of research over the last few decades. While these studies have brought interesting insights, specialization within each research area comes at the potential cost of a narrow and isolated view of the oculomotor system. In this review, we want to expand this perspective by looking at the interactions between the two most important types of voluntary eye movements: saccades and pursuit. Recent evidence indicates multiple interactions and shared signals at the behavioral and neurophysiological level for oculomotor control and for visual perception during pursuit and saccades. Oculomotor control seems to be based on shared position- and velocity-related information, which leads to multiple behavioral interactions and synergies. The distinction between position- and velocity-related information seems to be also present at the neurophysiological level. In addition, visual perception seems to be based on shared efferent signals about upcoming eye positions and velocities, which are to some degree independent of the actual oculomotor response. This review suggests an interactive perspective on the oculomotor system, based mainly on different types of sensory input, and less so on separate subsystems for saccadic or pursuit eye movements.
Collapse
Affiliation(s)
- Alexander Goettker
- Abteilung Allgemeine Psychologie and Center for Mind, Brain & Behavior, Justus-Liebig University Giessen, Germany.
| | - Karl R Gegenfurtner
- Abteilung Allgemeine Psychologie and Center for Mind, Brain & Behavior, Justus-Liebig University Giessen, Germany
| |
Collapse
|
15
|
Wang JZ, Kowler E. Micropursuit and the control of attention and eye movements in dynamic environments. J Vis 2021; 21:6. [PMID: 34347019 PMCID: PMC8340658 DOI: 10.1167/jov.21.8.6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
It is more challenging to plan eye movements during perceptual tasks performed in dynamic displays than in static displays. Decisions about the timing of saccades become more critical, and decisions must also involve smooth eye movements, as well as saccades. The present study examined eye movements when judging which of two moving discs would arrive first, or collide, at a common meeting point. Perceptual discrimination after training was precise (Weber fractions < 6%). Strategies reflected a combined contribution of saccades and smooth eye movements. The preferred strategy was to look near the meeting point when strategies were freely chosen. When strategies were assigned, looking near the meeting point produced better performance than switching between the discs. Smooth eye movements were engaged in two ways: (a) low-velocity smooth eye movements correlated with the motion of each disc (micropursuit) were found while the line of sight remained between the discs; and (b) spontaneous smooth pursuit of the pair of discs occurred after the perceptual report, when the discs moved as a pair along a common path. The results show clear preferences and advantages for those eye movement strategies during dynamic perceptual tasks that require minimal management or effort. In addition, smooth eye movements, whose involvement during perceptual tasks within dynamic displays may have previously escaped notice, provide useful indictors of the strategies used to select information and distribute attention during the performance of dynamic perceptual tasks.
Collapse
Affiliation(s)
- Jie Z Wang
- Department of Psychology, Rutgers University, Piscataway, NJ, USA.,http://orcid.org/0000-0002-8553-6706.,
| | - Eileen Kowler
- Department of Psychology, Rutgers University, Piscataway, NJ, USA.,http://orcid.org/0000-0001-7079-0376., https://ruccs.rutgers.edu/kowler
| |
Collapse
|
16
|
Abstract
SIGNIFICANCE After a 30-year gap, several studies on head and eye movements and gaze tracking in baseball batting have been performed in the last decade. These baseball studies may lead to training protocols for batting. Here we review these studies and compare the tracking behaviors with those in other sports.Baseball batters are often instructed to "keep your eye on the ball." Until recently, the evidence regarding whether batters follow this instruction and if there are benefits to following this instruction was limited. Baseball batting studies demonstrate that batters tend to move the head more than the eyes in the direction of the ball at least until a saccade occurs. Foveal gaze tracking is often maintained on the ball through the early portion of the pitch, so it can be said that baseball batters do keep the eyes on the ball. While batters place gaze at or near the point of bat-ball contact, the way this is accomplished varies. In some studies, foveal gaze tracking continues late in the pitch trajectory, whereas in other studies, anticipatory saccades occur. The relative advantages of these discrepant gaze strategies on perceptual processing and motor planning speed and accuracy are discussed, and other variables that may influence anticipatory saccades including the predictability of the pitch and the level of batter expertise are described. Further studies involving larger groups with different levels of expertise under game conditions are required to determine which gaze tracking strategies are most beneficial for baseball batting.
Collapse
|
17
|
Aguado B, López-Moliner J. Flexible viewing time when estimating time-to-contact in 3D parabolic trajectories. J Vis 2021; 21:9. [PMID: 33900365 PMCID: PMC8088230 DOI: 10.1167/jov.21.4.9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Obtaining reliable estimates of the time-to-contact (TTC) in a three-dimensional (3D) parabolic trajectory is still an open issue. A direct analysis of the optic flow cannot make accurate predictions for gravitationally accelerated objects. Alternatively, resorting to prior knowledge of gravity and size can provide accurate estimates of TTC in parabolic head-on trajectories, but its generalization depends on the specific geometry of the trajectory and particular moments. The aim of this work is to explore the preferred viewing windows to estimate TTC and how the available visual information affects these estimations. We designed a task in which participants, wearing an head-mounted display (HMD), had to time the moment a ball in a parabolic path returned at eye level. We used five trajectories for which accurate temporal predictions were available at different points of flight time. Our results show that our observers can predict both the trajectory of the ball and TTC based on the available visual information and previous experience with the task. However, the times at which our observers chose to gather the visual evidence did not match those in which visual information provided accurate TTC. Instead, they looked at the ball at relatively fixed temporal windows depending on the trajectory but not of TTC.
Collapse
Affiliation(s)
- Borja Aguado
- Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Catalonia, Spain.,
| | - Joan López-Moliner
- Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Catalonia, Spain.,
| |
Collapse
|
18
|
Fooken J, Kreyenmeier P, Spering M. The role of eye movements in manual interception: A mini-review. Vision Res 2021; 183:81-90. [PMID: 33743442 DOI: 10.1016/j.visres.2021.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/28/2021] [Accepted: 02/04/2021] [Indexed: 10/21/2022]
Abstract
When we catch a moving object in mid-flight, our eyes and hands are directed toward the object. Yet, the functional role of eye movements in guiding interceptive hand movements is not yet well understood. This review synthesizes emergent views on the importance of eye movements during manual interception with an emphasis on laboratory studies published since 2015. We discuss the role of eye movements in forming visual predictions about a moving object, and for enhancing the accuracy of interceptive hand movements through feedforward (extraretinal) and feedback (retinal) signals. We conclude by proposing a framework that defines the role of human eye movements for manual interception accuracy as a function of visual certainty and object motion predictability.
Collapse
Affiliation(s)
- Jolande Fooken
- Department of Psychology and Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada; Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, Canada.
| | - Philipp Kreyenmeier
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, Canada; Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada.
| | - Miriam Spering
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, Canada; Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada; Institute for Computing, Information, and Cognitive Systems, University of British Columbia, Vancouver, Canada
| |
Collapse
|
19
|
Cámara C, López-Moliner J, Brenner E, de la Malla C. Looking away from a moving target does not disrupt the way in which the movement toward the target is guided. J Vis 2021; 20:5. [PMID: 32407436 PMCID: PMC7409596 DOI: 10.1167/jov.20.5.5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
People usually follow a moving object with their gaze if they intend to interact with it. What would happen if they did not? We recorded eye and finger movements while participants moved a cursor toward a moving target. An unpredictable delay in updating the position of the cursor on the basis of that of the invisible finger made it essential to use visual information to guide the finger's ongoing movement. Decreasing the contrast between the cursor and the background from trial to trial made it difficult to see the cursor without looking at it. In separate experiments, either participants were free to hit the target anywhere along its trajectory or they had to move along a specified path. In the two experiments, participants tracked the cursor rather than the target with their gaze on 13% and 32% of the trials, respectively. They hit fewer targets when the contrast was low or a path was imposed. Not looking at the target did not disrupt the visual guidance that was required to deal with the delays that we imposed. Our results suggest that peripheral vision can be used to guide one item to another, irrespective of which item one is looking at.
Collapse
|
20
|
de Brouwer AJ, Flanagan JR, Spering M. Functional Use of Eye Movements for an Acting System. Trends Cogn Sci 2021; 25:252-263. [PMID: 33436307 DOI: 10.1016/j.tics.2020.12.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 12/05/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
Movements of the eyes assist vision and support hand and body movements in a cooperative way. Despite their strong functional coupling, different types of movements are usually studied independently. We integrate knowledge from behavioral, neurophysiological, and clinical studies on how eye movements are coordinated with goal-directed hand movements and how they facilitate motor learning. Understanding the coordinated control of eye and hand movements can provide important insights into brain functions that are essential for performing or learning daily tasks in health and disease. This knowledge can also inform applications such as robotic manipulation and clinical rehabilitation.
Collapse
Affiliation(s)
- Anouk J de Brouwer
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.
| | - J Randall Flanagan
- Centre for Neuroscience Studies, Queen's University, Kingston, Canada; Department of Psychology, Queen's University, Kingston, Canada
| | - Miriam Spering
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| |
Collapse
|
21
|
Mann DL, Nakamoto H, Logt N, Sikkink L, Brenner E. Predictive eye movements when hitting a bouncing ball. J Vis 2020; 19:28. [PMID: 31891654 DOI: 10.1167/19.14.28] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Predictive eye movements targeted toward the direction of ball bounce are a feature of gaze behavior when intercepting a target soon after it has bounced. However, there is conjecture over the exact location toward which these predictive eye movements are directed, and whether gaze during this period is moving or instead "lies in wait" for the ball to arrive. Therefore, the aim of this study was to further examine the location toward which predictive eye movements are made when hitting a bouncing ball. We tracked the eye and head movements of 23 novice participants who attempted to hit approaching tennis balls in a virtual environment. The balls differed in time from bounce to contact (300, 550, and 800 ms). Results revealed that participants made predictive saccades shortly before the ball bounced in two-thirds of all trials. These saccades were directed several degrees above the position at which the ball bounced, rather than toward the position at which it bounced or toward a position the ball would occupy shortly after the bounce. After the saccade, a separation of roles for the eyes and head ensured that gaze continued to change so that it was as close as possible to the ball soon after bounce. Smooth head movements were responsible for the immediate and ongoing changes in gaze to align it with the ball in the lateral direction, while eye movements realigned gaze with the ball in the vertical direction from approximately 100 ms after the ball changed its direction of motion after bounce. We conclude that predictive saccades direct gaze above the location at which the ball will bounce, presumably in order to facilitate ball tracking after the bounce.
Collapse
Affiliation(s)
- David L Mann
- Department of Human Movement Sciences, Amsterdam Movement Sciences and Institute of Brain and Behavior Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Hiroki Nakamoto
- Faculty of Physical Education, National Institute of Fitness and Sports in Kanoya, Kagoshima, Japan
| | - Nadine Logt
- Department of Human Movement Sciences, Amsterdam Movement Sciences and Institute of Brain and Behavior Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Lieke Sikkink
- Department of Human Movement Sciences, Amsterdam Movement Sciences and Institute of Brain and Behavior Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Eli Brenner
- Department of Human Movement Sciences, Amsterdam Movement Sciences and Institute of Brain and Behavior Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| |
Collapse
|
22
|
Langridge RW, Marotta JJ. Grasping a 2D virtual target: The influence of target position and movement on gaze and digit placement. Hum Mov Sci 2020; 71:102625. [PMID: 32452441 DOI: 10.1016/j.humov.2020.102625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 03/06/2020] [Accepted: 04/16/2020] [Indexed: 10/24/2022]
Abstract
While much has been learned about the visual pursuit and motor strategies used to intercept a moving object, less research has focused on the coordination of gaze and digit placement when grasping moving stimuli. Participants grasped 2D computer generated square targets that either encouraged placement of the index finger and thumb along the horizontal midline (Control targets) or had narrow "notches" in the top and bottom surfaces of the target, intended to discourage digit placement near the midline (Experimental targets). In Experiment 1, targets remained stationary at the left, middle, or right side of the screen. Gaze and digit placement were biased toward the closest side of non-central targets, and toward the midline of center targets. These locations were shifted rightward when grasping Experimental targets, suggesting participants prioritized visibility of the target. In Experiment 2, participants grasped horizontally translating targets at early, middle, or late stages of travel. Average gaze and digit placement were consistently positioned behind the moving target's horizontal midline when grasping. Gaze was directed farther behind the midline of Experimental targets, suggesting the absence of a flat central grasp location pulled participants' gaze toward the trailing edge. Participants placed their digits at positions closer to the horizontal midline of leftward moving targets, suggesting participants were compensating for the added mechanical constraints associated with grasping targets moving in a direction contralateral to the grasping hand. These results suggest participants minimize the effort associated with reaching to non-central targets by grasping the nearest side when the target is stationary, but grasp the trailing side of moving targets, even if this means placing the digits at locations on the far side of the target, potentially limiting visibility of the target.
Collapse
Affiliation(s)
- Ryan W Langridge
- Perception and Action Lab, Department of Psychology, 190 Dysart Rd, University of Manitoba, Winnipeg, MB R3T-2N2, Canada.
| | - Jonathan J Marotta
- Perception and Action Lab, Department of Psychology, 190 Dysart Rd, University of Manitoba, Winnipeg, MB R3T-2N2, Canada.
| |
Collapse
|
23
|
Fooken J, Spering M. Eye movements as a readout of sensorimotor decision processes. J Neurophysiol 2020; 123:1439-1447. [PMID: 32159423 DOI: 10.1152/jn.00622.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Real-world tasks, such as avoiding obstacles, require a sequence of interdependent choices to reach accurate motor actions. Yet, most studies on primate decision making involve simple one-step choices. Here we analyze motor actions to investigate how sensorimotor decisions develop over time. In a go/no-go interception task human observers (n = 42) judged whether a briefly presented moving target would pass (interceptive hand movement required) or miss (no hand movement required) a strike box while their eye and hand movements were recorded. Go/no-go decision formation had to occur within the first few hundred milliseconds to allow time-critical interception. We found that the earliest time point at which eye movements started to differentiate actions (go versus no-go) preceded hand movement onset. Moreover, eye movements were related to different stages of decision making. Whereas higher eye velocity during smooth pursuit initiation was related to more accurate interception decisions (whether or not to act), faster pursuit maintenance was associated with more accurate timing decisions (when to act). These results indicate that pursuit initiation and maintenance are continuously linked to ongoing sensorimotor decision formation.NEW & NOTEWORTHY Here we show that eye movements are a continuous indicator of decision processes underlying go/no-go actions. We link different stages of decision formation to distinct oculomotor events during open- and closed-loop smooth pursuit. Critically, the earliest time point at which eye movements differentiate actions preceded hand movement onset, suggesting shared sensorimotor processing for eye and hand movements. These results emphasize the potential of studying eye movements as a readout of cognitive processes.
Collapse
Affiliation(s)
- Jolande Fooken
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Miriam Spering
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada.,Center for Brain Health, University of British Columbia, Vancouver, Canada.,Institute for Computing, Information and Cognitive Systems, University of British Columbia, Vancouver, Canada
| |
Collapse
|
24
|
Zhao H, Straub D, Rothkopf CA. The visual control of interceptive steering: How do people steer a car to intercept a moving target? J Vis 2019; 19:11. [PMID: 31830240 DOI: 10.1167/19.14.11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The visually guided interception of a moving target is a fundamental visuomotor task that humans can do with ease. But how humans carry out this task is still unclear despite numerous empirical investigations. Measurements of angular variables during human interception have suggested three possible strategies: the pursuit strategy, the constant bearing angle strategy, and the constant target-heading strategy. Here, we review previous experimental paradigms and show that some of them do not allow one to distinguish among the three strategies. Based on this analysis, we devised a virtual driving task that allows investigating which of the three strategies best describes human interception. Crucially, we measured participants' steering, head, and gaze directions over time for three different target velocities. Subjects initially aligned head and gaze in the direction of the car's heading. When the target appeared, subjects centered their gaze on the target, pointed their head slightly off the heading direction toward the target, and maintained an approximately constant target-heading angle, whose magnitude varied across participants, while the target's bearing angle continuously changed. With a second condition, in which the target was partially occluded, we investigated several alternative hypotheses about participants' visual strategies. Overall, the results suggest that interceptive steering is best described by the constant target-heading strategy and that gaze and head are coordinated to continuously acquire visual information to achieve successful interception.
Collapse
Affiliation(s)
- Huaiyong Zhao
- Institute of Psychology, Technical University Darmstadt, Darmstadt, Germany
| | - Dominik Straub
- Institute of Psychology, Technical University Darmstadt, Darmstadt, Germany
| | - Constantin A Rothkopf
- Institute of Psychology, Technical University Darmstadt, Darmstadt, Germany.,Center for Cognitive Science, Technical University Darmstadt, Germany.,Frankfurt Institute for Advanced Studies, Goethe University, Germany
| |
Collapse
|
25
|
Affiliation(s)
- Katja Fiehler
- Department of Psychology, Justus Liebig University, Giessen, Germany
- Center for Mind, Brain, and Behavior (CMBB), Universities of Marburg and Giessen, Germany
| | - Eli Brenner
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, The Netherlands
| | - Miriam Spering
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, Canada
| |
Collapse
|
26
|
Abstract
Grip force has been studied widely in a variety of interaction and movement tasks, however, not much is known about the timing of the grip force control in preparation for interaction with objects. For example, it is unknown whether and how the temporal preparation for a collision is related to (the prediction of) the impact load. To study this question, we examined the anticipative timing of the grip force in preparation for impact loads. We designed a collision task with different types of load forces in a controlled virtual environment. Participants interacted with a robotic device (KINARM, BKIN Technologies, Kingston) whose handles were equipped with force sensors which the participants held in precision grip. Representations of the hand and objects were visually projected on a virtual reality display and forces were applied onto the participant's hand to simulate a collision with the virtual objects. The collisions were alternating between the two hands to allow transfer and learning between the hands. The results show that there is immediate transfer of object information between the two hands, since the grip force levels are (almost) fully adjusted after one collision with the opposite hand. The results also show that the grip force levels are nicely adjusted based on the mass and stiffness of the object. Surprisingly, the temporal onset of the grip force build up did not depend on the impact load, so that participants avoid slippage by adjusting the other grip force characteristics (e.g., grip force level and rate of change), therefore considering these self-imposed timing constraints. With the use of catch trials, for which no impact occurred, we further analyzed the temporal profile of the grip force. The catch trial data showed that the timing of the grip force peak is also independent of the impact load and its timing, which suggests a time-locked planning of the complete grip force profile.
Collapse
|
27
|
Abstract
Smooth pursuit eye movements maintain the line of sight on smoothly moving targets. Although often studied as a response to sensory motion, pursuit anticipates changes in motion trajectories, thus reducing harmful consequences due to sensorimotor processing delays. Evidence for predictive pursuit includes (a) anticipatory smooth eye movements (ASEM) in the direction of expected future target motion that can be evoked by perceptual cues or by memory for recent motion, (b) pursuit during periods of target occlusion, and (c) improved accuracy of pursuit with self-generated or biologically realistic target motions. Predictive pursuit has been linked to neural activity in the frontal cortex and in sensory motion areas. As behavioral and neural evidence for predictive pursuit grows and statistically based models augment or replace linear systems approaches, pursuit is being regarded less as a reaction to immediate sensory motion and more as a predictive response, with retinal motion serving as one of a number of contributing cues.
Collapse
Affiliation(s)
- Eileen Kowler
- Department of Psychology, Rutgers University, Piscataway, New Jersey 08854, USA; , ,
| | - Jason F Rubinstein
- Department of Psychology, Rutgers University, Piscataway, New Jersey 08854, USA; , ,
| | - Elio M Santos
- Department of Psychology, Rutgers University, Piscataway, New Jersey 08854, USA; , , .,Current affiliation: Department of Psychology, State University of New York, College at Oneonta, Oneonta, New York 13820, USA;
| | - Jie Wang
- Department of Psychology, Rutgers University, Piscataway, New Jersey 08854, USA; , ,
| |
Collapse
|
28
|
de la Malla C, Rushton SK, Clark K, Smeets JBJ, Brenner E. The predictability of a target’s motion influences gaze, head, and hand movements when trying to intercept it. J Neurophysiol 2019; 121:2416-2427. [DOI: 10.1152/jn.00917.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Does the predictability of a target’s movement and of the interception location influence how the target is intercepted? In a first experiment, we manipulated the predictability of the interception location. A target moved along a haphazardly curved path, and subjects attempted to tap on it when it entered a hitting zone. The hitting zone was either a large ring surrounding the target’s starting position (ring condition) or a small disk that became visible before the target appeared (disk condition). The interception location gradually became apparent in the ring condition, whereas it was immediately apparent in the disk condition. In the ring condition, subjects pursued the target with their gaze. Their heads and hands gradually moved in the direction of the future tap position. In the disk condition, subjects immediately directed their gaze toward the hitting zone by moving both their eyes and heads. They also moved their hands to the future tap position sooner than in the ring condition. In a second and third experiment, we made the target’s movement more predictable. Although this made the targets easier to pursue, subjects now shifted their gaze to the hitting zone soon after the target appeared in the ring condition. In the disk condition, they still usually shifted their gaze to the hitting zone at the beginning of the trial. Together, the experiments show that predictability of the interception location is more important than predictability of target movement in determining how we move to intercept targets. NEW & NOTEWORTHY We show that if people are required to intercept a target at a known location, they direct their gaze to the interception point as soon as they can rather than pursuing the target with their eyes for as long as possible. The predictability of the interception location rather than the predictability of the path to that location largely determines how the eyes, head, and hand move.
Collapse
Affiliation(s)
- Cristina de la Malla
- Vision and Control of Action Group, Department of Cognition, Development, and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Simon K. Rushton
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Kait Clark
- School of Psychology, Cardiff University, Cardiff, United Kingdom
- Department of Health and Social Sciences, University of the West of England, Bristol, United Kingdom
| | - Jeroen B. J. Smeets
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Eli Brenner
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
29
|
Delle Monache S, Lacquaniti F, Bosco G. Ocular tracking of occluded ballistic trajectories: Effects of visual context and of target law of motion. J Vis 2019; 19:13. [PMID: 30952164 DOI: 10.1167/19.4.13] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In tracking a moving target, the visual context may provide cues for an observer to interpret the causal nature of the target motion and extract features to which the visual system is weakly sensitive, such as target acceleration. This information could be critical when vision of the target is temporarily impeded, requiring visual motion extrapolation processes. Here we investigated how visual context influences ocular tracking of motion either congruent or not with natural gravity. To this end, 28 subjects tracked computer-simulated ballistic trajectories either perturbed in the descending segment with altered gravity effects (0g/2g) or retaining natural-like motion (1g). Shortly after the perturbation (550 ms), targets disappeared for either 450 or 650 ms and became visible again until landing. Target motion occurred with either quasi-realistic pictorial cues or a uniform background, presented in counterbalanced order. We analyzed saccadic and pursuit movements after 0g and 2g target-motion perturbations and for corresponding intervals of unperturbed 1g trajectories, as well as after corresponding occlusions. Moreover, we considered the eye-to-target distance at target reappearance. Tracking parameters differed significantly between scenarios: With a neutral background, eye movements did not depend consistently on target motion, whereas with pictorial background they showed significant dependence, denoting better tracking of accelerated targets. These results suggest that oculomotor control is tuned to realistic properties of the visual scene.
Collapse
Affiliation(s)
- Sergio Delle Monache
- Department of Systems Medicine, Neuroscience Section, University of Rome Tor Vergata, Rome, Italy.,Center of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuromotor Physiology, Santa Lucia Foundation, Rome, Italy
| | - Francesco Lacquaniti
- Department of Systems Medicine, Neuroscience Section, University of Rome Tor Vergata, Rome, Italy.,Center of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuromotor Physiology, Santa Lucia Foundation, Rome, Italy
| | - Gianfranco Bosco
- Department of Systems Medicine, Neuroscience Section, University of Rome Tor Vergata, Rome, Italy.,Center of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuromotor Physiology, Santa Lucia Foundation, Rome, Italy
| |
Collapse
|
30
|
Goettker A, Brenner E, Gegenfurtner KR, de la Malla C. Corrective saccades influence velocity judgments and interception. Sci Rep 2019; 9:5395. [PMID: 30931972 PMCID: PMC6443687 DOI: 10.1038/s41598-019-41857-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/19/2019] [Indexed: 11/16/2022] Open
Abstract
In daily life we often interact with moving objects in tasks that involve analyzing visual motion, like catching a ball. To do so successfully we track objects with our gaze, using a combination of smooth pursuit and saccades. Previous work has shown that the occurrence and direction of corrective saccades leads to changes in the perceived velocity of moving objects. Here we investigate whether such changes lead to equivalent biases in interception. Participants had to track moving targets with their gaze, and in separate sessions either judge the targets' velocities or intercept them by tapping on them. We separated trials in which target movements were tracked with pure pursuit from trials in which identical target movements were tracked with a combination of pursuit and corrective saccades. Our results show that interception errors are shifted in accordance with the observed influence of corrective saccades on velocity judgments. Furthermore, while the time at which corrective saccades occurred did not affect velocity judgments, it did influence their effect in the interception task. Corrective saccades around 100 ms before the tap had a stronger effect on the endpoint error than earlier saccades. This might explain why participants made earlier corrective saccades in the interception task.
Collapse
Affiliation(s)
- Alexander Goettker
- Abteilung Allgemeine Psychologie, Justus-Liebig University Giessen, 35394, Giessen, Germany.
| | - Eli Brenner
- Department of Human Movement Sciences, Institute for Brain and Behavior Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Karl R Gegenfurtner
- Abteilung Allgemeine Psychologie, Justus-Liebig University Giessen, 35394, Giessen, Germany
| | - Cristina de la Malla
- Department of Human Movement Sciences, Institute for Brain and Behavior Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
31
|
Brenner E, Smeets JBJ. Continuously updating one’s predictions underlies successful interception. J Neurophysiol 2018; 120:3257-3274. [DOI: 10.1152/jn.00517.2018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This paper reviews our understanding of the interception of moving objects. Interception is a demanding task that requires both spatial and temporal precision. The required precision must be achieved on the basis of imprecise and sometimes biased sensory information. We argue that people make precise interceptive movements by continuously adjusting their movements. Initial estimates of how the movement should progress can be quite inaccurate. As the movement evolves, the estimate of how the rest of the movement should progress gradually becomes more reliable as prediction is replaced by sensory information about the progress of the movement. The improvement is particularly important when things do not progress as anticipated. Constantly adjusting one’s estimate of how the movement should progress combines the opportunity to move in a way that one anticipates will best meet the task demands with correcting for any errors in such anticipation. The fact that the ongoing movement might have to be adjusted can be considered when determining how to move, and any systematic anticipation errors can be corrected on the basis of the outcome of earlier actions.
Collapse
Affiliation(s)
- Eli Brenner
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Jeroen B. J. Smeets
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
32
|
Higuchi T, Nagami T, Nakata H, Kanosue K. Head-eye movement of collegiate baseball batters during fastball hitting. PLoS One 2018; 13:e0200443. [PMID: 30016367 PMCID: PMC6049917 DOI: 10.1371/journal.pone.0200443] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/26/2018] [Indexed: 11/18/2022] Open
Abstract
Successful baseball hitting involves a combination of highly trained perceptual skills and forceful bat swing motions. The purpose of the present study was to quantify the horizontal movement of the head and eyes while baseball batters hit a fastball to clarify a visual strategy for this highly trained interceptive task. Six collegiate baseball players hit a fastball that was launched from a pitching machine. The ball speed was 31.9 m·s-1 for the Slow Ball Task and 40.3 m·s-1 for the Fast Ball Task. Horizontal head movements were analysed using images that were captured by two high-speed video cameras. The Horizontal eye movement was recorded with electrooculography. The angular speed of the horizontal head and eye movements during hitting were divided into four time periods (I-40 = 21–40% of total ball-flight, I-60 = 41–60% of total ball-flight, I-80 = 61–80% of total ball-flight, I-100 = 81–100% of total ball-flight) and analysed using analysis of variance and a Tukey post-hoc multiple-comparison. In the Slow Ball Task, the horizontal angular velocity of the head during I-80 was significantly faster than that during I-40 (p < 0.05). In the Fast Ball Task, the horizontal angular velocity of the head during I-80 was significantly faster than that during I-40 and I-60 (p < 0.05). These results indicated that the tracking motion of the head became faster as the launched ball came close to the batters, but there was no change in the angular tracking motion of the eyes. Therefore, rapid eye movement may not be suitable to accurately estimate the ball’s future location during fastball hitting based on the eye-centered coordinates. Our findings suggest that conventional vision training with a wide range of saccadic or smooth-pursuit eye movements does not reflect the characteristics of tracking strategies during baseball hitting.
Collapse
Affiliation(s)
- Takatoshi Higuchi
- Fukuoka Institute of Technology, Faculty of Socio-Environmental Studies, Fukuoka, Japan
- * E-mail:
| | - Tomoyuki Nagami
- Kitasato University, College of Liberal Arts and Sciences, Sagamihara, Japan
| | - Hiroki Nakata
- Nara Women’s University, Faculty of Human Life and Environment, Nara, Japan
| | | |
Collapse
|
33
|
Cámara C, de la Malla C, López-Moliner J, Brenner E. Eye movements in interception with delayed visual feedback. Exp Brain Res 2018; 236:1837-1847. [PMID: 29675715 PMCID: PMC6010481 DOI: 10.1007/s00221-018-5257-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 04/07/2018] [Indexed: 11/25/2022]
Abstract
The increased reliance on electronic devices such as smartphones in our everyday life exposes us to various delays between our actions and their consequences. Whereas it is known that people can adapt to such delays, the mechanisms underlying such adaptation remain unclear. To better understand these mechanisms, the current study explored the role of eye movements in interception with delayed visual feedback. In two experiments, eye movements were recorded as participants tried to intercept a moving target with their unseen finger while receiving delayed visual feedback about their own movement. In Experiment 1, the target randomly moved in one of two different directions at one of two different velocities. The delay between the participant’s finger movement and movement of the cursor that provided feedback about the finger movements was gradually increased. Despite the delay, participants followed the target with their gaze. They were quite successful at hitting the target with the cursor. Thus, they moved their finger to a position that was ahead of where they were looking. Removing the feedback showed that participants had adapted to the delay. In Experiment 2, the target always moved in the same direction and at the same velocity, while the cursor’s delay varied across trials. Participants still always directed their gaze at the target. They adjusted their movement to the delay on each trial, often succeeding to intercept the target with the cursor. Since their gaze was always directed at the target, and they could not know the delay until the cursor started moving, participants must have been using peripheral vision of the delayed cursor to guide it to the target. Thus, people deal with delays by directing their gaze at the target and using both experience from previous trials (Experiment 1) and peripheral visual information (Experiment 2) to guide their finger in a way that will make the cursor hit the target.
Collapse
Affiliation(s)
- Clara Cámara
- Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Cristina de la Malla
- Faculty of Behavioural and Movement Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Joan López-Moliner
- Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Eli Brenner
- Faculty of Behavioural and Movement Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| |
Collapse
|
34
|
Goettker A, Braun DI, Schütz AC, Gegenfurtner KR. Execution of saccadic eye movements affects speed perception. Proc Natl Acad Sci U S A 2018; 115:2240-2245. [PMID: 29440494 PMCID: PMC5834663 DOI: 10.1073/pnas.1704799115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Due to the foveal organization of our visual system we have to constantly move our eyes to gain precise information about our environment. Doing so massively alters the retinal input. This is problematic for the perception of moving objects, because physical motion and retinal motion become decoupled and the brain has to discount the eye movements to recover the speed of moving objects. Two different types of eye movements, pursuit and saccades, are combined for tracking. We investigated how the way we track moving targets can affect the perceived target speed. We found that the execution of corrective saccades during pursuit initiation modifies how fast the target is perceived compared with pure pursuit. When participants executed a forward (catch-up) saccade they perceived the target to be moving faster. When they executed a backward saccade they perceived the target to be moving more slowly. Variations in pursuit velocity without corrective saccades did not affect perceptual judgments. We present a model for these effects, assuming that the eye velocity signal for small corrective saccades gets integrated with the retinal velocity signal during pursuit. In our model, the execution of corrective saccades modulates the integration of these two signals by giving less weight to the retinal information around the time of corrective saccades.
Collapse
Affiliation(s)
- Alexander Goettker
- Abteilung Allgemeine Psychologie, Justus Liebig University Giessen, 35394 Giessen, Germany
| | - Doris I Braun
- Abteilung Allgemeine Psychologie, Justus Liebig University Giessen, 35394 Giessen, Germany
| | - Alexander C Schütz
- Department of Psychology, Philipps University of Marburg, 35032 Marburg, Germany
| | - Karl R Gegenfurtner
- Abteilung Allgemeine Psychologie, Justus Liebig University Giessen, 35394 Giessen, Germany;
| |
Collapse
|
35
|
Malla CDL, Smeets JBJ, Brenner E. Potential Systematic Interception Errors are Avoided When Tracking the Target with One's Eyes. Sci Rep 2017; 7:10793. [PMID: 28883471 PMCID: PMC5589827 DOI: 10.1038/s41598-017-11200-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 08/21/2017] [Indexed: 11/22/2022] Open
Abstract
Directing our gaze towards a moving target has two known advantages for judging its trajectory: the spatial resolution with which the target is seen is maximized, and signals related to the eyes' movements are combined with retinal cues to better judge the target's motion. We here explore whether tracking a target with one's eyes also prevents factors that are known to give rise to systematic errors in judging retinal speeds from resulting in systematic errors in interception. Subjects intercepted white or patterned disks that moved from left to right across a large screen at various constant velocities while either visually tracking the target or fixating the position at which they were required to intercept the target. We biased retinal motion perception by moving the pattern within the patterned targets. This manipulation led to large systematic errors in interception when subjects were fixating, but not when they were tracking the target. The reduction in the errors did not depend on how smoothly the eyes were tracking the target shortly before intercepting it. We propose that tracking targets with one's eyes when one wants to intercept them makes one less susceptible to biases in judging their motion.
Collapse
Affiliation(s)
- Cristina de la Malla
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, NL - 1081BT, Amsterdam, The Netherlands.
| | - Jeroen B J Smeets
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, NL - 1081BT, Amsterdam, The Netherlands
| | - Eli Brenner
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, NL - 1081BT, Amsterdam, The Netherlands
| |
Collapse
|
36
|
Ross NM, Goettker A, Schütz AC, Braun DI, Gegenfurtner KR. Discrimination of curvature from motion during smooth pursuit eye movements and fixation. J Neurophysiol 2017; 118:1762-1774. [PMID: 28659462 DOI: 10.1152/jn.00324.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 11/22/2022] Open
Abstract
Smooth pursuit and motion perception have mainly been investigated with stimuli moving along linear trajectories. Here we studied the quality of pursuit movements to curved motion trajectories in human observers and examined whether the pursuit responses would be sensitive enough to discriminate various degrees of curvature. In a two-interval forced-choice task subjects pursued a Gaussian blob moving along a curved trajectory and then indicated in which interval the curve was flatter. We also measured discrimination thresholds for the same curvatures during fixation. Motion curvature had some specific effects on smooth pursuit properties: trajectories with larger amounts of curvature elicited lower open-loop acceleration, lower pursuit gain, and larger catch-up saccades compared with less curved trajectories. Initially, target motion curvatures were underestimated; however, ∼300 ms after pursuit onset pursuit responses closely matched the actual curved trajectory. We calculated perceptual thresholds for curvature discrimination, which were on the order of 1.5 degrees of visual angle (°) for a 7.9° curvature standard. Oculometric sensitivity to curvature discrimination based on the whole pursuit trajectory was quite similar to perceptual performance. Oculometric thresholds based on smaller time windows were higher. Thus smooth pursuit can quite accurately follow moving targets with curved trajectories, but temporal integration over longer periods is necessary to reach perceptual thresholds for curvature discrimination.NEW & NOTEWORTHY Even though motion trajectories in the real world are frequently curved, most studies of smooth pursuit and motion perception have investigated linear motion. We show that pursuit initially underestimates the curvature of target motion and is able to reproduce the target curvature ∼300 ms after pursuit onset. Temporal integration of target motion over longer periods is necessary for pursuit to reach the level of precision found in perceptual discrimination of curvature.
Collapse
Affiliation(s)
- Nicholas M Ross
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany; and
| | - Alexander Goettker
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany; and
| | - Alexander C Schütz
- AG Allgemeine und Biologische Psychologie, Philipps-Universität Marburg, Marburg, Germany
| | - Doris I Braun
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany; and
| | - Karl R Gegenfurtner
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany; and
| |
Collapse
|
37
|
Attention is allocated closely ahead of the target during smooth pursuit eye movements: Evidence from EEG frequency tagging. Neuropsychologia 2017. [DOI: 10.1016/j.neuropsychologia.2017.06.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
38
|
Kreyenmeier P, Fooken J, Spering M. Context effects on smooth pursuit and manual interception of a disappearing target. J Neurophysiol 2017; 118:404-415. [PMID: 28515287 DOI: 10.1152/jn.00217.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 04/25/2017] [Accepted: 05/12/2017] [Indexed: 11/22/2022] Open
Abstract
In our natural environment, we interact with moving objects that are surrounded by richly textured, dynamic visual contexts. Yet most laboratory studies on vision and movement show visual objects in front of uniform gray backgrounds. Context effects on eye movements have been widely studied, but it is less well known how visual contexts affect hand movements. Here we ask whether eye and hand movements integrate motion signals from target and context similarly or differently, and whether context effects on eye and hand change over time. We developed a track-intercept task requiring participants to track the initial launch of a moving object ("ball") with smooth pursuit eye movements. The ball disappeared after a brief presentation, and participants had to intercept it in a designated "hit zone." In two experiments (n = 18 human observers each), the ball was shown in front of a uniform or a textured background that either was stationary or moved along with the target. Eye and hand movement latencies and speeds were similarly affected by the visual context, but eye and hand interception (eye position at time of interception, and hand interception timing error) did not differ significantly between context conditions. Eye and hand interception timing errors were strongly correlated on a trial-by-trial basis across all context conditions, highlighting the close relation between these responses in manual interception tasks. Our results indicate that visual contexts similarly affect eye and hand movements but that these effects may be short-lasting, affecting movement trajectories more than movement end points.NEW & NOTEWORTHY In a novel track-intercept paradigm, human observers tracked a briefly shown object moving across a textured, dynamic context and intercepted it with their finger after it had disappeared. Context motion significantly affected eye and hand movement latency and speed, but not interception accuracy; eye and hand position at interception were correlated on a trial-by-trial basis. Visual context effects may be short-lasting, affecting movement trajectories more than movement end points.
Collapse
Affiliation(s)
- Philipp Kreyenmeier
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.,Graduate Program in Neuro-Cognitive Psychology, Ludwig Maximilian University, Munich, Germany
| | - Jolande Fooken
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Miriam Spering
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada; .,Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada.,Center for Brain Health, University of British Columbia, Vancouver, Canada.,Institute for Information, Computing and Cognitive Systems, University of British Columbia, Vancouver, Canada; and.,International Collaboration on Repair Discoveries, Vancouver, Canada
| |
Collapse
|
39
|
Brenner E, Smeets JB. Accumulating visual information for action. PROGRESS IN BRAIN RESEARCH 2017; 236:75-95. [DOI: 10.1016/bs.pbr.2017.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
40
|
Abstract
The existence of a central fovea, the small retinal region with high analytical performance, is arguably the most prominent design feature of the primate visual system. This centralization comes along with the corresponding capability to move the eyes to reposition the fovea continuously. Past research on visual perception was mainly concerned with foveal vision while the observers kept their eyes stationary. Research on the role of eye movements in visual perception emphasized their negative aspects, for example, the active suppression of vision before and during the execution of saccades. But is the only benefit of our precise eye movement system to provide high acuity of the small foveal region, at the cost of retinal blur during their execution? In this review, I will compare human visual perception with and without saccadic and smooth pursuit eye movements to emphasize different aspects and functions of eye movements. I will show that the interaction between eye movements and visual perception is optimized for the active sampling of information across the visual field and for the calibration of different parts of the visual field. The movements of our eyes and visual information uptake are intricately intertwined. The two processes interact to enable an optimal perception of the world, one that we cannot fully grasp by doing experiments where observers are fixating a small spot on a display.
Collapse
|
41
|
Brenner E, Rodriguez IA, Muñoz VE, Schootemeijer S, Mahieu Y, Veerkamp K, Zandbergen M, van der Zee T, Smeets JB. How Can People Be so Good at Intercepting Accelerating Objects if They Are so Poor at Visually Judging Acceleration? Iperception 2016; 7:2041669515624317. [PMID: 27482367 PMCID: PMC4954742 DOI: 10.1177/2041669515624317] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
People are known to be very poor at visually judging acceleration. Yet, they are extremely proficient at intercepting balls that fall under gravitational acceleration. How is this possible? We previously found that people make systematic errors when trying to tap on targets that move with different constant accelerations or decelerations on interleaved trials. Here, we show that providing contextual information that indicates how the target will decelerate on the next trial does not reduce such errors. Such errors do rapidly diminish if the same deceleration is present on successive trials. After observing several targets move with a particular acceleration or deceleration without attempting to tap on them, participants tapped as if they had never experienced the acceleration or deceleration. Thus, people presumably deal with acceleration when catching or hitting a ball by compensating for the errors that they made on preceding attempts.
Collapse
Affiliation(s)
- Eli Brenner
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Inés Abalo Rodriguez
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Victor Estal Muñoz
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Sabine Schootemeijer
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Yannick Mahieu
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Kirsten Veerkamp
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Marit Zandbergen
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Tim van der Zee
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Jeroen Bj Smeets
- Department of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| |
Collapse
|
42
|
Anticipatory gaze strategies when grasping moving objects. Exp Brain Res 2015; 233:3413-23. [PMID: 26289482 DOI: 10.1007/s00221-015-4413-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 08/08/2015] [Indexed: 10/23/2022]
Abstract
Grasping moving objects involves both spatial and temporal predictions. The hand is aimed at a location where it will meet the object, rather than the position at which the object is seen when the reach is initiated. Previous eye-hand coordination research from our laboratory, utilizing stationary objects, has shown that participants' initial gaze tends to be directed towards the eventual location of the index finger when making a precision grasp. This experiment examined how the speed and direction of a computer-generated block's movement affect gaze and selection of grasp points. Results showed that when the target first appeared, participants anticipated the target's eventual movement by fixating well ahead of its leading edge in the direction of eventual motion. Once target movement began, participants shifted their fixation to the leading edge of the target. Upon reach initiation, participants then fixated towards the top edge of the target. As seen in our previous work with stationary objects, final fixations tended towards the final index finger contact point on the target. Moreover, gaze and kinematic analyses revealed that it was direction that most influenced fixation locations and grasp points. Interestingly, participants fixated further ahead of the target's leading edge when the direction of motion was leftward, particularly at the slower speed-possibly the result of mechanical constraints of intercepting leftward-moving targets with one's right hand.
Collapse
|
43
|
Cesqui B, Mezzetti M, Lacquaniti F, d'Avella A. Gaze behavior in one-handed catching and its relation with interceptive performance: what the eyes can't tell. PLoS One 2015; 10:e0119445. [PMID: 25793989 PMCID: PMC4368737 DOI: 10.1371/journal.pone.0119445] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 01/30/2015] [Indexed: 01/08/2023] Open
Abstract
In ball sports, it is usually acknowledged that expert athletes track the ball more accurately than novices. However, there is also evidence that keeping the eyes on the ball is not always necessary for interception. Here we aimed at gaining new insights on the extent to which ocular pursuit performance is related to catching performance. To this end, we analyzed eye and head movements of nine subjects catching a ball projected by an actuated launching apparatus. Four different ball flight durations and two different ball arrival heights were tested and the quality of ocular pursuit was characterized by means of several timing and accuracy parameters. Catching performance differed across subjects and depended on ball flight characteristics. All subjects showed a similar sequence of eye movement events and a similar modulation of the timing of these events in relation to the characteristics of the ball trajectory. On a trial-by-trial basis there was a significant relationship only between pursuit duration and catching performance, confirming that keeping the eyes on the ball longer increases catching success probability. Ocular pursuit parameters values and their dependence on flight conditions as well as the eye and head contributions to gaze shift differed across subjects. However, the observed average individual ocular behavior and the eye-head coordination patterns were not directly related to the individual catching performance. These results suggest that several oculomotor strategies may be used to gather information on ball motion, and that factors unrelated to eye movements may underlie the observed differences in interceptive performance.
Collapse
Affiliation(s)
- Benedetta Cesqui
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
- Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy
- * E-mail:
| | - Maura Mezzetti
- Department of Economics and Finance, University of Rome Tor Vergata, Rome, Italy
| | - Francesco Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
- Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy
- Department of Systems Medicine, Neuroscience Section, University of Rome, Tor Vergata, Rome, Italy
| | - Andrea d'Avella
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Messina, Italy
| |
Collapse
|
44
|
Brenner E, Smeets JBJ. How moving backgrounds influence interception. PLoS One 2015; 10:e0119903. [PMID: 25767873 PMCID: PMC4358934 DOI: 10.1371/journal.pone.0119903] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 02/03/2015] [Indexed: 11/29/2022] Open
Abstract
Reaching movements towards an object are continuously guided by visual information about the target and the arm. Such guidance increases precision and allows one to adjust the movement if the target unexpectedly moves. On-going arm movements are also influenced by motion in the surrounding. Fast responses to motion in the surrounding could help cope with moving obstacles and with the consequences of changes in one’s eye orientation and vantage point. To further evaluate how motion in the surrounding influences interceptive movements we asked subjects to tap a moving target when it reached a second, static target. We varied the direction and location of motion in the surrounding, as well as details of the stimuli that are known to influence eye movements. Subjects were most sensitive to motion in the background when such motion was near the targets. Whether or not the eyes were moving, and the direction of the background motion in relation to the direction in which the eyes were moving, had very little influence on the response to the background motion. We conclude that the responses to background motion are driven by motion near the target rather than by a global analysis of the optic flow and its relation with other information about self-motion.
Collapse
Affiliation(s)
- Eli Brenner
- Faculty of Human Movement Sciences, MOVE Research Institute, VU University, Amsterdam, The Netherlands
- * E-mail:
| | - Jeroen B. J. Smeets
- Faculty of Human Movement Sciences, MOVE Research Institute, VU University, Amsterdam, The Netherlands
| |
Collapse
|
45
|
Eye movements and manual interception of ballistic trajectories: effects of law of motion perturbations and occlusions. Exp Brain Res 2014; 233:359-74. [DOI: 10.1007/s00221-014-4120-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 09/29/2014] [Indexed: 01/01/2023]
|
46
|
Brenner E, Driesen B, Smeets JBJ. Precise timing when hitting falling balls. Front Hum Neurosci 2014; 8:342. [PMID: 24904380 PMCID: PMC4033095 DOI: 10.3389/fnhum.2014.00342] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/05/2014] [Indexed: 12/03/2022] Open
Abstract
People are extremely good at hitting falling balls with a baseball bat. Despite the ball's constant acceleration, they have been reported to time hits with a standard deviation of only about 7 ms. To examine how people achieve such precision, we compared performance when there were no added restrictions, with performance when looking with one eye, when vision was blurred, and when various parts of the ball's trajectory were hidden from view. We also examined how the size of the ball and varying the height from which it was dropped influenced temporal precision. Temporal precision did not become worse when vision was blurred, when the ball was smaller, or when balls falling from different heights were randomly interleaved. The disadvantage of closing one eye did not exceed expectations from removing one of two independent estimates. Precision was higher for slower balls, but only if the ball being slower meant that one saw it longer before the hit. It was particularly important to see the ball while swinging the bat. Together, these findings suggest that people time their hits so precisely by using the changing elevation throughout the swing to adjust the bat's movement to that of the ball.
Collapse
Affiliation(s)
- Eli Brenner
- Faculty of Human Movement Sciences, MOVE Research Institute, VU University Amsterdam Netherlands
| | - Ben Driesen
- Faculty of Human Movement Sciences, MOVE Research Institute, VU University Amsterdam Netherlands
| | - Jeroen B J Smeets
- Faculty of Human Movement Sciences, MOVE Research Institute, VU University Amsterdam Netherlands
| |
Collapse
|
47
|
Brenner E, Cañal-Bruland R, van Beers RJ. How the required precision influences the way we intercept a moving object. Exp Brain Res 2013; 230:207-18. [PMID: 23857171 DOI: 10.1007/s00221-013-3645-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 07/01/2013] [Indexed: 11/26/2022]
Abstract
Do people perform a given motor task differently if it is easy than if it is difficult? To find out, we asked subjects to intercept moving virtual targets by tapping on them with their fingers. We examined how their behaviour depended on the required precision. Everything about the task was the same on all trials except the extent to which the fingertip and target had to overlap for the target to be considered hit. The target disappeared with a sound if it was hit and deflected away from the fingertip if it was missed. In separate sessions, the required precision was varied from being quite lenient about the required overlap to being very demanding. Requiring a higher precision obviously decreased the number of targets that were hit, but it did not reduce the variability in where the subjects tapped with respect to the target. Requiring a higher precision reduced the systematic deviations from landing at the target centre and the lag-one autocorrelation in such deviations, presumably because subjects received information about smaller deviations from hitting the target centre. We found no evidence for lasting effects of training with a certain required precision. All the results can be reproduced with a model in which the precision of individual movements is independent of the required precision, and in which feedback associated with missing the target is used to reduce systematic errors. We conclude that people do not approach this motor task differently when it is easy than when it is difficult.
Collapse
Affiliation(s)
- Eli Brenner
- Faculty of Human Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands,
| | | | | |
Collapse
|
48
|
Hardiess G, Hansmann-Roth S, Mallot HA. Gaze movements and spatial working memory in collision avoidance: a traffic intersection task. Front Behav Neurosci 2013; 7:62. [PMID: 23760667 PMCID: PMC3674308 DOI: 10.3389/fnbeh.2013.00062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 05/22/2013] [Indexed: 11/15/2022] Open
Abstract
Street crossing under traffic is an everyday activity including collision detection as well as avoidance of objects in the path of motion. Such tasks demand extraction and representation of spatio-temporal information about relevant obstacles in an optimized format. Relevant task information is extracted visually by the use of gaze movements and represented in spatial working memory. In a virtual reality traffic intersection task, subjects are confronted with a two-lane intersection where cars are appearing with different frequencies, corresponding to high and low traffic densities. Under free observation and exploration of the scenery (using unrestricted eye and head movements) the overall task for the subjects was to predict the potential-of-collision (POC) of the cars or to adjust an adequate driving speed in order to cross the intersection without collision (i.e., to find the free space for crossing). In a series of experiments, gaze movement parameters, task performance, and the representation of car positions within working memory at distinct time points were assessed in normal subjects as well as in neurological patients suffering from homonymous hemianopia. In the following, we review the findings of these experiments together with other studies and provide a new perspective of the role of gaze behavior and spatial memory in collision detection and avoidance, focusing on the following questions: (1) which sensory variables can be identified supporting adequate collision detection? (2) How do gaze movements and working memory contribute to collision avoidance when multiple moving objects are present and (3) how do they correlate with task performance? (4) How do patients with homonymous visual field defects (HVFDs) use gaze movements and working memory to compensate for visual field loss? In conclusion, we extend the theory of collision detection and avoidance in the case of multiple moving objects and provide a new perspective on the combined operation of external (bottom-up) and internal (top-down) cues in a traffic intersection task.
Collapse
Affiliation(s)
- Gregor Hardiess
- Cognitive Neuroscience, Department of Biology, Institute of Neurobiology, University of Tübingen Tübingen, Germany
| | | | | |
Collapse
|
49
|
Louveton N, Bootsma RJ, Guerin P, Berthelon C, Montagne G. Intersection crossing considered as intercepting a moving traffic gap: effects of task and environmental constraints. Acta Psychol (Amst) 2012; 141:287-94. [PMID: 23079189 DOI: 10.1016/j.actpsy.2012.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 08/13/2012] [Accepted: 08/14/2012] [Indexed: 10/27/2022] Open
Abstract
Safely crossing an intersection requires that drivers actively control their approach to the intersection with respect to characteristics of the flow of incoming traffic. To further our understanding of the perceptual-motor processes involved in this demanding manoeuvre, we designed a driving simulator experiment in which 13 participants actively negotiated intersections by passing through a gap in the train of incoming traffic. Task constraints were manipulated by varying the size of the traffic gap and the initial conditions with respect to the time of arrival of the traffic gap at the intersection. Environment constraints were manipulated by varying the intersection geometry through changes in the angle formed by the crossroads. The results revealed that the task constraints systematically gave rise to continuous and gradual adjustments in approach velocity, initiated well before arriving at the intersection. These functionally appropriate adjustments allowed the drivers to safely cross the intersection, generally just slightly ahead of the center of the traffic gap. Notwithstanding the fact that the geometry of the intersection did not affect the spatiotemporal constraints of the crossing task, approach behavior varied systematically over geometries, suggesting that drivers rely on the traffic gap's bearing angle. Overall, the pattern of results is indicative of a continuous coupling between perception and action, analogous to that observed in locomotor interception tasks.
Collapse
|
50
|
Brenner E, van Dam M, Berkhout S, Smeets JB. Timing the moment of impact in fast human movements. Acta Psychol (Amst) 2012; 141:104-11. [PMID: 22864313 DOI: 10.1016/j.actpsy.2012.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 03/28/2012] [Accepted: 07/03/2012] [Indexed: 11/27/2022] Open
Abstract
The reported resolution of timing the moment of impact in fast human movements differs widely depending on the task. Surprisingly, better timing is reported for the demanding task of batting a ball than for the much simpler task of tapping in synchrony with two hands. We wondered whether this is because a sizeable part of timing variability arises from misjudging the distance in the direction of one's own movement, so that moving faster (as the bat does when moving toward a ball) improves timing. We found that moving faster does indeed improve timing in both the above-mentioned tasks. After removing the proposed contribution of misjudging the distance in the direction of one's own movement, we estimated that the remaining standard deviation in timing is just over 6ms for both tasks.
Collapse
|