Influence of postural constraints on eye and head latency during voluntary rotations

Anastasopoulos, D.; Bringoux, Lionel; Lee, P.Y.; Naushahi, M.J.; Bronstein, Adolfo M.

doi:10.1016/j.visres.2012.11.011

Cited by 11 publications

(13 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such ankle stabilization is likely part of an anticipatory postural adjustment in preparation of a complex movement sequence (Assaiante et al 2000 ), in this case ultimately aiming to shift the eyes in space. Given that in conventional head-fixed saccadic experiments, anticipatory adjustments and assemblage of multisegmental synergies are not required, our EMG findings thus agree with the view that the long eye latencies observed in this paradigm relate to active delaying of the eye saccades until all anticipatory postural adjustments and segments are ready to go (Scotto Di Cesare et al 2013 ).…”

Section: Discussionsupporting

confidence: 88%

“…Finally, the timing of segmental activation within this motor synergy was further evaluated by recording the initiation of electromyographic (EMG) activity from several muscles involved in stepping. A top-down sequence of segmental movement initiation has been observed when subjects turn on the spot in upright posture with the eye starting to rotate first and the foot last (Hollands et al 2004 ), but data show that eye saccade initiation is considerably delayed when compared with data from sitting subjects (Scotto Di Cesare et al 2013 ). Therefore, we hypothesized that this saccadic delay is introduced in order to optimize the coordination between the large number of rotating segments and the anticipatory postural adjustments required before the onset of movement.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fast gaze reorientations by combined movements of the eye, head, trunk and lower extremities

et al. 2015

View full text Add to dashboard Cite

Large reorientations of the line of sight, involving combined rotations of the eyes, head, trunk and lower extremities, are executed either as fast single-step or as slow multiple-step gaze transfers. In order to obtain more insight into the mechanisms of gaze and multisegmental movement control, we have investigated time-optimal gaze shifts (i.e. with the instruction to move as fast as possible) during voluntary whole-body rotations to remembered targets up to 180° eccentricity performed by standing healthy humans in darkness. Fast, accurate, single-step movement patterns occurred in approximately 70 % of trials, i.e. considerably more frequently than in previous studies with the instruction to turn at freely chosen speed (30 %). Head-in-space velocity in these cases was significantly higher than during multiple-step transfers and displayed a conspicuously regular bell-shaped profile, increasing smoothly to a peak and then decreasing slowly until realignment with the target. Head-in-space acceleration was on average not different during reorientations to the different target eccentricities. In contrast, head-in-space velocity increased with target eccentricity due to the longer duration of the acceleration phase implemented during trials to more distant targets. Eye saccade amplitude approached the eye-in-orbit mechanical limit and was unrelated to eye/head velocity, duration or target eccentricity. Overall, the combined movement was stereotyped such that the first two principal components accounted for data variance almost up to gaze shift end, suggesting that the three mechanical degrees of freedom under consideration (eye-in-orbit, head-on-trunk and trunk-in-space) are on average reduced to two kinematic degrees of freedom (i.e. eye, head-in-space). Synchronous EMG activity in the anterior tibial and gastrocnemius muscles preceded the onset of eye rotation. Since the magnitude and timing of peak head-in-space velocity were scaled with target eccentricity and because head-on-trunk and trunk-in-space displacements were on average linearly correlated, we propose a separate controller for head-in-space movement, whereas the movement of the eye-in-space may be, in contrast, governed by global, i.e. gaze feedback. The rapid progression of the line of sight can be sustained, and the reactivation of the vestibulo-ocular reflex would be postponed, until gaze error approaches zero only in association with a strong head-in-space neural control signal.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Fast gaze reorientations by combined movements of the eye, head, trunk and lower extremities

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Variations in biomechanics caused differences in eyemovement behavior, which was most evident in the results from our analysis of the Pasta task (Table 3, Figure 4a). Postural constraints have previously been found to affect eye behavior; specifically, Di Cesare et al (2013) have found that eye movements were delayed when whole-body rotations were used to fixate a target. As well, Freedman (2008) has shown that saccades increased in velocity as head movements were restricted.…”

Section: Biomechanics Of Movement Affect Eye-movement Behaviormentioning

confidence: 99%

Using synchronized eye and motion tracking to determine high-precision eye-movement patterns during object-interaction tasks

et al. 2018

View full text Add to dashboard Cite

This study explores the role that vision plays in sequential object interactions. We used a head-mounted eye tracker and upper-limb motion capture to quantify visual behavior while participants performed two standardized functional tasks. By simultaneously recording eye and motion tracking, we precisely segmented participants' visual data using the movement data, yielding a consistent and highly functionally resolved data set of real-world object-interaction tasks. Our results show that participants spend nearly the full duration of a trial fixating on objects relevant to the task, little time fixating on their own hand when reaching toward an object, and slightly more time-although still very little-fixating on the object in their hand when transporting it. A consistent spatial and temporal pattern of fixations was found across participants. In brief, participants fixate an object to be picked up at least half a second before their hand arrives at the object and stay fixated on the object until they begin to transport it, at which point they shift their fixation directly to the drop-off location of the object, where they stay fixated until the object is successfully released. This pattern provides additional evidence of a common system for the integration of vision and object interaction in humans, and is consistent with theoretical frameworks hypothesizing the distribution of attention to future action targets as part of eye and hand-movement preparation. Our results thus aid the understanding of visual attention allocation during planning of object interactions both inside and outside the field of view.

show abstract

“…Reed-Jones et al (2014) have reported similar eyemovement latencies to light cues in sitting and standing positions in older adults compared with the young. Interestingly, while not using an older adult population, a number of studies have reported longer eye-movement latencies in young participants during whole body movements executed in the standing position, suggesting that the CNS requires additional time to process eye movements in these situations (Hollands et al 2004;Anastasopoulos et al 2009;Di Cesare et al 2013). If postural constraints increase eye-movement latencies to target displacements in older adults over and above those of their younger counterparts, it may be predicted that they need to devote more attentional resources to the dual task of standing and fixating targets, as postural constraints increase.…”

Section: Introductionmentioning

confidence: 99%

Age-related effects of increasing postural challenge on eye movement onset latencies to visual targets

et al. 2016

View full text Add to dashboard Cite

When a single light cue is given in the visual field, our eyes orient towards it with an average latency of 200 ms. If a second cue is presented at or around the time of the response to the first, a secondary eye movement occurs that represents a re-orientation to the new target. While studies have shown that eye movement latencies to 'single-step' targets may or may not be lengthened with age, secondary eye-movements (during 'double-step' displacements) are significantly delayed with increasing age. The aim of this study was to investigate if the postural challenge posed simply by standing (as opposed to sitting) results in significantly longer eye movement latencies in older adults compared to the young. Ten young (<35 years) and 10 older healthy adults (>65 years) participated in the study. They were required to fixate upon a central target and move their eyes in response to 2 types of stimuli: 1) a single-step perturbation of target position either 15º to the right or left, and 2) a double-step target displacement incorporating an initial target jump to the right or left by 15º, followed after 200 ms, by a shift of target position to the opposite side (e.g., +15º then -15º). All target displacement conditions were executed in sit and stand positions with the participant at the same distance from the targets. Eye movements were recorded using electro-oculography. Older adults did not show significantly longer eye movement latencies than the younger adults for single-step target displacements, and postural configuration (stand compared to sit) had no effect upon latencies for either group. We categorised double-step trials into those during which the second light changed after or before the onset of the eye shift to the first light. For the former category, young participants showed faster secondary eye shifts to the second light in the standing position, while the older adults did not. For the latter category of double-step trial, young participants showed no significant difference between sit and stand secondary eye movement latencies, but older adults were significantly longer standing compared to sitting. The older adults were significantly longer than the younger adults across both postural conditions, regardless of when the second light change occurred during the eye shift to the first light. We suggest that older adults require greater time and perhaps attentional processes to execute eye movements to unexpected changes of target position when faced with the need to maintain standing balance.

show abstract

Influence of postural constraints on eye and head latency during voluntary rotations

Cited by 11 publications

References 21 publications

Fast gaze reorientations by combined movements of the eye, head, trunk and lower extremities

Fast gaze reorientations by combined movements of the eye, head, trunk and lower extremities

Using synchronized eye and motion tracking to determine high-precision eye-movement patterns during object-interaction tasks

Age-related effects of increasing postural challenge on eye movement onset latencies to visual targets

Contact Info

Product

Resources

About