Stroboscopic Vision Research Articles

The effect of stroboscopic vision on performance in a football specific assessment

ABSTRACT Purpose: This study aimed to investigate how restricted visual feedback affects performance in a football-specific skills assessment that incorporates the coupling of football a-specific perceptual information with football-specific motor actions. Methods: The Footbonaut is a 14x14m cage equipped with 8 ball dispensers and 64 targets measuring passing accuracy and time to complete each pass. Eighty-four amateur male participants (19.5 ± 5.4 years old; 13.1 ± 6.0 years experience) completed two sessions under two different visual conditions: stroboscopic and normal vision. Results: A linear regression revealed that performance under normal conditions was significantly associated (p < 0.001) with the performance decrement under stroboscopic vision conditions. Players were then subdivided into skilled (S; top 25%) and less-skilled (LS; bottom 25%) groups. Restricting visual feedback impacted the average time required to complete the passes in both S and LS groups equally (S: +0.18 s; LS: + 0.12 s; p = 0.385), yet S athletes’ accuracy (−11.1%) was more heavily reduced under restricted visual conditions compared to their Normal condition; whereas the LS athletes’ accuracy remained relatively unchanged (−1.9%). Conclusion: Therefore, stroboscopic vision may be used to induce performance errors during practice to stimulate larger training effects, particularly in more skilled players.

Short- and Long-Term Stroboscopic Training Effects on Visuomotor Performance in Elite Youth Sports. Part 1: Reaction and Behavior.

Recent research suggests that stroboscopic training is an effective tool to improve visual and visuomotor performance. However, many studies were limited by small samples, short training interventions, inexperienced athletes, and an exclusive focus on short-term effects. This first part of the study evaluates the short- and long-term effects of stroboscopic training on visuomotor reaction speed in elite athletes. Forty-five young elite badminton athletes participated in this study, of which 32 (13.7 yr) were included in the final data analysis. Participants were assigned to an intervention (stroboscopic vision) or control group (normal vision). Both groups performed identical badminton-specific training drills implemented into the regular training schedule. Before and after a 10-wk training period and after a 6-wk retention interval, athletes performed a laboratory reaction test to determine EMG onset and visuomotor reaction time (VMRT). In addition, a field test investigated stroboscopic training effects on the quality of ball-racquet contact and net drop performance. VMRT decreased immediately after stroboscopic training (pre, 251 ms; post, 238 ms; P = 0.005, d = 0.63), and reactions remained significantly faster after the retention interval (retention, 241 ms; P = 0.041, d = 0.50). Analyses on EMG onset data suggested these adaptations were attributable to the premotor rather than the motor time. VMRT remained unchanged in the control group (pre, 252 ms; post, 256; retention, 253 ms; P > 0.99). Field test performance improvements were observed for the quality of ball-racquet contact and net drop performance; however, changes were not different between groups. Stroboscopic training induced short- and long-term accelerations of visuomotor reaction speed in elite badminton players. Stroboscopic eyewear may be an effective training tool to accelerate visuomotor reactions in highly skilled athletes.

Short- and Long-Term Stroboscopic Training Effects on Visuomotor Performance in Elite Youth Sports. Part 2: Brain-Behavior Mechanisms.

Stroboscopic training has repeatedly been shown to improve visuomotor abilities. However, although performance improvements were attributed to visual processes, information on the neurophysiological mechanisms is missing. Part 2 of this study investigated the effects of stroboscopic training on neural visual and motor functions and its contribution to training-induced changes in visuomotor reaction time. Forty-five young elite badminton athletes participated in this study, of which 32 (age, 13.7 yr) were included in the final data analysis. Participants were assigned to an intervention (stroboscopic vision) or control group (normal vision). Before and after a 10-wk training and after a 6-wk retention period, participants performed visual perception and reaction tasks in response to visual motion stimuli. The N2 and N2-r motion onset visual-evoked potentials, its linear combination (Vlc), and the BA6 negativity potential were determined using a 64-channel EEG. A significant TIME-GROUP effect was observed for the Vlc score (P = 0.019, ηp2 = 0.18), indicating a lower Vlc in the intervention group. However, post hoc tests did not reach significance. Within-subject correlation analyses revealed that changes in reaction speed were related to latency changes in N2 (r = 0.59, P < 0.001), N2-r (r = -0.64, P < 0.001), and the combined Vlc (r = 0.68, P < 0.001). Regression analyses across participants including multiple (N2/N2-r) or single (Vlc) predictors provided an explained variance of >60% (N2/N2-r, r2 = 0.62; Vlc, r2 = 0.64). No training effects or correlations were observed for the BA6 negativity. The results indicate that faster visuomotor reactions after stroboscopic training are accompanied by accelerated visual perception and processing, whereas motor processes seemed to be unaffected. Stroboscopic training may be promising to specifically address the visual system in visuomotor-demanding sports.

Effects Of Stroboscopic Vision On Postural Control In Individuals With And Without Chronic Ankle Instability

Chronic ankle instability (CAI) patients have consistently displayed postural control deficits. Previous research postulated that CAI patients rely more on the utilization of visual feedback than controls to compensate for the proprioceptive deficits after lateral ankle sprains. However, little is known about how reduced visual feedback would alter dynamic postural control in CAI patients relative to controls and copers. PURPOSE: To identify the effect of visual feedback disruption via stroboscopic glasses on dynamic postural control among groups of CAI, coper, and control. METHODS: 20 CAI (10M, 10F, 23.6±3.9 yr, 174.5±11.8 cm, 76.3±17.5 kg), 20 coper (10M, 10F, 22.2±1.4 yr, 176.4±10.2 cm, 69.3±10.9 kg), and 20 control (10M, 10F, 22.6±2.7 yr, 174.4±7.2 cm, 80.0±24.4 kg) subjects were categorized according to the Foot and Ankle Ability Measure (FAAM) and Modified Ankle Instability Index (MAII) questionnaires. Each subject performed three trials of a single-leg-hop stabilization test with eyes open (EO) and stroboscopic vision (SV). Force data (200 Hz) were collected using an in-ground force plate to calculate the dynamic postural stability index (DPSI) and directional stability indices (medial/lateral, anterior/posterior, vertical). Two-way repeated ANOVAs (group × condition) were used to examine the differences between condition (EO, SV) and group (CAI, coper, control). RESULTS: Visual condition main effect was driven by differences between EO and SV during dynamic postural control (p<0.001). Only CAI patients displayed altered DPSI scores between EO and SV (p=0.005). However, no differences were observed in copers (p=0.31) and controls (p=0.99). Regardless of visual condition, CAI patients displayed dynamic postural control deficits relative to controls (p=0.003) but no differences between CAI patients and copers (p=0.45). For the directional stability indices, each group displayed no differences between visual conditions. CONCLUSION: CAI patients rely more on visual feedback during dynamic postural control than copers and controls. However, they may have decreased ability to compensate for the disrupted visual feedback during dynamic movement. Stroboscopic glasses could be effective visual-disruption devices during dynamic movement tasks regardless of lateral ankle sprain history.

Balance Training with Stroboscopic Vision is Superior to Balance Training Alone for Chronic Ankle Instability

Balance Training with Stroboscopic Vision is Superior to Balance Training Alone for Chronic Ankle Instability

Effect of stroboscopic vision on depth jump performance in female NCAA Division I volleyball athletes

ABSTRACT Anticipation of ground reaction force (GRF) in depth jumping requires multisensory integration of exteroceptive, vestibular, and proprioceptive inputs. Vision contributes to the anticipation of GRF in drop landings and may influence depth jump performance when disrupted. The purpose of this investigation was to evaluate the effects of stroboscopic vision on depth jump performance. Thirteen female NCAA Division I volleyball athletes completed a testing protocol consisting of 0.38 m depth jumps under condition of full vision and stroboscopic vision at strobe frequencies of 4 and 1.75 Hz. Depth jump performance was assessed via the Reactive Strength Index (RSI) and time-series vertical GRF (vGRF) data. Main effects of stroboscopic vision were evaluated for statistical significance via Repeated Measures Multivariate Analysis of Variance with post hoc multiple paired t-tests (α = 0.05). RSI (p < 0.001) and rebound jump height (p = 0.006) were lower in the 1.75 Hz stroboscopic condition versus full vision, while ground contact time (p = 0.008), and rate of vertical ground reaction force development (p = 0.016) were greater in the 1.75 Hz stroboscopic condition versus full vision. Stroboscopic vision could be used to modify the intensity of depth jumping and considered for inclusion into plyometric training.

Stroboscopic Vision as a Dynamic Sensory Reweighting Alternative to the Sensory Organization Test.

The sensory organization test (SOT) is a standard for quantifying sensory dependence via sway-referenced conditions (sway-referenced support and sway-referenced vision [SRV]). However, the SOT is limited to expensive equipment. Thus, a practical version of the SOT is more commonly employed-the clinical test for sensory integration in balance; however, it fails to induce postural instability to the level of SRV. Determine if Stroboscopic vision (SV), characterized by intermittent visual blocking, may provide an alternative to the SRV for assessing postural stability. Descriptive laboratory study. Research laboratory. Eighteen participants (9 males, 9 females; age = 22.1 [2.1]y, height = 169.8 [8.5]cm, weight = 66.5 [10.6]kg). Participants completed the SOT conditions, and then repeated SOT conditions 2 and 5 with SV created by specialized eyewear. A repeated-measures analysis of variance was completed on the time-to-boundary metrics of center-of-pressure excursion in the anteroposterior and mediolateral directions in order to determine the difference between the full-vision, SV, and SRV conditions. Postural stability with either SRV or SV was significantly worse than with full vision (P < .05), with no significant difference between SV and SRV (P > .05). Limits of agreement analysis revealed similar effects of SV and SRV except for unstable surface mediolateral time-to-boundary. In general, SV was found to induce a degree of postural instability similar to that induced by SRV, indicating that SV could be a portable and relatively inexpensive alternative for the assessment of sensory dependence and reweighting.

Balance Training With Stroboscopic Vision

Balance Training With Stroboscopic Vision

Effects Of Stroboscopic Vision On Reactive Strength Index Scores In Female Ncaa Division I Volleyball Players.

It is believed that ACL injury risk is multifaceted and includes structural, biomechanical, and cognitive factors. Recently, it is observed that overreliance on exteroception (visual stimuli) following ACL rehabilitation may increase the risk of re-rupture. There may be utility in using stroboscopic vision as an enhancement to plyometric movements and neuromuscular ACL-prevention programs. PURPOSE: To evaluate the effects of stroboscopic vision on Reactive Strength Index (RSI) scores in female NCAA Division I volleyball players. METHODS: Thirteen female NCAA Division I volleyball players performed three trials of depth jumping across five conditions: (1) 0.38 m - no visual restriction, (2) 0.53 m - no visual restriction, (3) 0.69 m - no visual restriction, (4) 0.38 m - high-frequency stroboscopic vision (H-f), and (5) 0.38 m - low-frequency stroboscopic vision (L-f). For all trials, the RSI, rebound jump height (RJH; m), and ground contact time (GCT; s) were computed from vertical ground reaction force data acquired via a tri-axial force platform. To evaluate the statistical significance of results, a Multivariate General Linear Model Analysis of Variance (GLM ANOVA) was performed using RSI, RJH (m), and GCT (s) as dependent measures. The five depth jump conditions were included as levels within a single condition factor. Statistical significance was set at an alpha level of 0.05. RESULTS: Main effects of depth jump condition were observed for RSI and GCT (s) (p = 0.001), but not for RJH (m) (p = 0.101). Post-hoc comparisons revealed that RSI scores were lower for stroboscopic conditions (H-f: 0.75 ± 0.16; L-f: 0.72 ± 0.16) versus no visual restriction (0.38 m: 0.80 ± 0.17; 0.53 m: 0.79 ± 0.17; 0.69 m: 0.79 ± 0.16). Post-hoc comparisons revealed that GCT (s) was greater for stroboscopic conditions (H-f: 0.47 ± 0.07 s; L-f: 0.49 ± 0.07 s) versus no visual restriction (0.38 m: 0.46 ± 0.07 s; 0.53 m: 0.45 ± 0.07 s; 0.69 m: 0.45 ± 0.07 s). CONCLUSION: Integrating stroboscopic vision into the depth jump movement reduced RSI scores in a sample of female NCAA Division I volleyball players, which was attributable to longer GCTs (s). The results suggest that adding stroboscopic vision to plyometric movements may increase the difficulty of the task from either a cognitive or biophysical perspective.

Can Stroboscopic Training Improve Judgments of Time-to-Collision?

The aim of this study was to determine whether training with stroboscopic viewing could improve time-to-collision (TTC) judgments, which have importance in real-world tasks such as driving. Prior research demonstrated that training with stroboscopic vision can improve motion coherence thresholds, improve anticipatory timing performance for laterally moving objects, and can protect against performance degradation over time. Participants viewed computer simulations of an object that moved and then disappeared. In two separate experiments, the object approached the observer or moved laterally toward a target, representing different optical flow patterns. Participants judged TTC by pressing a button when they thought the object would hit them (approach), or the target (lateral). Performance was measured during four sessions-pretest, intervention, immediately after intervention, and 10 min after intervention. Both stroboscopic training and repeated practice improved performance over time for approach motion (decrease in constant error) and stroboscopic training protected against performance degradation for lateral motion (no decrement in variable error), but only when TTC was 3.0 s. There was no difference between training and repeated practice. Under certain conditions, stroboscopic training may improve TTC judgments. However, effects of stroboscopic training depend on the nature of the optical flow pattern. It is important to determine the conditions under which training can improve TTC judgments which have importance in real-world tasks such as driving. If individuals can be trained to judge TTC more accurately, they may benefit from driver training programs.

Stroboscopic Vision When Interacting With Multiple Moving Objects: Perturbation Is Not the Same as Elimination.

Motivated by recent findings of improved perceptual processing and perceptual-motor skill following stroboscopic vision training, the current study examined the performance and acquisition effects of stroboscopic vision methods that afford a different visual experience. In Experiment 1, we conducted a within-subject design study to examine performance of a multiple object tracking (MOT) task in different stroboscopic vision conditions (Nike Vapor Strobe®, PLATO visual occlusion, and intermittent display presentation) operating at 5.6, 3.2, or 1.8 Hz. We found that participants maintained MOT performance in the Vapor Strobe condition irrespective of strobe rate. However, MOT performance deteriorated as strobe rate was reduced in the other two stroboscopic vision conditions. Moreover, at the lowest strobe rate (1.8 Hz) there was an increase in probe reaction time, thus indicating an increased attentional demand due to the stroboscopic vision. In Experiment 2, we conducted a mixed design study to examine if practice in different stroboscopic vision conditions (Nike Vapor Strobe® and PLATO visual occlusion) influenced acquisition of a novel precision-aiming task [i.e., multiple object avoidance (MOA) task] compared to a normal vision group. Participants in the PLATO visual occlusion group exhibited worse performance during practice than the Vapor Strobe and normal vision groups. At post-test, the Vapor Strobe group demonstrated greater success and reduced end-point error than the normal vision and PLATO groups. We interpret these findings as showing that both an intermittent perturbation (Nike Vapor Strobe®) and elimination (PLATO visual occlusion and intermittent display presentation) of visual motion and form are more attention demanding (Experiment 1), however, the intermittent perturbation, but not elimination, of visual motion and form can facilitate acquisition of perceptual-motor skill (Experiment 2) in situations where it is necessary to maintain and update a spatio-temporal representation of multiple moving objects.

Effects of Stroboscopic Vision on Reactive Balance

Effects of Stroboscopic Vision on Reactive Balance

Stroboscopic vision and sustained attention during coincidence-anticipation

We compared coincidence-anticipation performance in normal vision and stroboscopic vision as a function of time-on-task. Participants estimated the arrival time of a real object that moved with constant acceleration (−0.7, 0, +0.7 m/s2) in a pseudo-randomised order across 4 blocks of 30 trials in both vision conditions, received in a counter-balanced order. Participants (n = 20) became more errorful (accuracy and variability) in the normal vision condition as a function of time-on-task, whereas performance was maintained in the stroboscopic vision condition. We interpret these data as showing that participants failed to maintain coincidence-anticipation performance in the normal vision condition due to monotony and attentional underload. In contrast, the stroboscopic vision condition placed a greater demand on visual-spatial memory for motion extrapolation, and thus participants did not experience the typical vigilance decrement in performance. While short-term adaptation effects from practicing in stroboscopic vision are promising, future work needs to consider for how long participants can maintain effortful processing, and whether there are negative carry-over effects from cognitive fatigue when transferring to normal vision.

Stroboscopic Vision to Induce Sensory Reweighting During Postural Control.

Patients with somatosensory deficits have been found to rely more on visual feedback for postural control. However, current balance tests may be limited in identifying increased visual dependence (sensory reweighting to the visual system), as options are typically limited to eyes open or closed conditions with no progressions between. To assess the capability of stroboscopic glasses to induce sensory reweighting of visual input during single-leg balance. Descriptive Laboratory 18 healthy subjects without vision or balance disorders or lower extremity injury history (9 females; age = 22.1 ± 2.1 y; height = 169.8 ± 8.5 cm; mass = 66.5 ± 10.6 kg) participated. Subjects performed 3 trials of unipedal stance for 10 s with eyes open (EO) and closed (EC), and with stroboscopic vision (SV) that was completed with specialized eyewear that intermittently cycled between opaque and transparent for 100 ms at a time. Balance tasks were performed on firm and foam surfaces, with the order randomized. Ten center-of-pressure parameters were computed. Separate ANOVAs with repeated measures found significant differences between the 3 visual conditions on both firm (Ps=<.001) and foam (Ps=<.001 to .005) surfaces for all measures. For trials on firm surface, almost all measures showed that balance with SV was significantly impaired relative to EO, but less impaired than EC. On the foam surface, almost all postural stability measures demonstrated significant impairments with SV compared with EO, but the impairment with SV was similar to EC. SV impairment of single-leg balance was large on the firm surface, but not to the same degree as EC. However, the foam surface disruption to somatosensory processing and sensory reweighting to vision lead to greater disruptive effects of SV to the same level as EC. This indicates that when the somatosensory system is perturbed even a moderate decrease in visual feedback (SV) may induce an EC level impairment to postural control during single-leg stance.

Effects of Stroboscopic Vision on Sensory Organization Test

Effects of Stroboscopic Vision on Sensory Organization Test

Examining the effects of stroboscopic vision

Visual and attentional abilities can differ greatly from one individual to another, and within an individual over time. Most differences between individuals are deeply rooted (e.g., between those who suffer from ADHD and those who do not), and most ability changes for an individual over time seem to arise from extensive, long-term training (e.g., perceptual learning effects, habitual video game playing). Relatively less evidence exists for more immediate improvements in visual cognition abilities through training procedures. Enhancement that can occur quickly could be highly valuable given the potential benefits of enhanced vision and attention in many arenas, including athletic activities. Athletes often must respond in millisecond time scales and any improvement in their ability to process incoming visual information has promise to enhance their performance. Using a new athletic training product that was presented at the 2010 Vision Sciences Society Demo Night, we provide evidence of improved visual abilities after training. Participants completed several computer-based visual cognition experiments (e.g., a motion coherence test) before and after engaging in training with simple sports activities (e.g., playing catch) while either wearing a new product called “Nike Strobes” or control eyewear. Nike Strobes are eyewear that use battery-powered liquid crystal stroboscopic filters (alternating between transparent and opaque) in the lenses to restrict incoming visual information and the control eyewear had clear lenses. Participants completed multiple 24-minute training sessions. Those who trained with the Nike Strobes showed greater improvements than those in the control group, revealing training benefits due to the stroboscopic experiences. The Strobe eyewear offer a potentially powerful visual training tool as they can be easily incorporated into normal activities and the strobe rate can be adjusted to progressively limit more incoming visual information.

Examining the effects of stroboscopic vision

Examining the effects of stroboscopic vision

Stroboscopic vision: deleuze and cixous

Tous ces morceaux, mais entiers, que Je suis et n'arrive pas a etre (Cixous 1976:400)1 ‘All these fragments, but whole ones, which “I” am and do not manage to be’ (all translations from the French ...