Effect of heading perception on microsaccade dynamics

European Journal of Sport Science

et al. 2020

Self Cite

Experts keep a steady final fixation at a specific location just before final movement initiation, the so-called "quiet eye" (QE). However, the eyes are rarely "quiet", and small eye movements occur during visual fixation. The current research investigated the subtle eye movements and underlying mechanisms immediately prior to and during QE. The gaze behaviour of 8 intermediate-level goalkeepers was recorded as they moved (either left or right) in an attempt to predict the future direction of the ball during a soccer penalty kick. Goalkeepers were more likely to predict the direction of the penalty, which was coupled with delaying movement initiation. The temporal sequence of microsaccade rates dropped ∼1000 ms before goalkeepers' final movement initiation. Saccade rates increased, reaching a peak ∼500 ms before final movement initiation, concomitant with microsaccades reduction. Microsaccades predicted the goalkeepers' direction, oriented to the right when goalkeepers moved to the right, and conversely to the left when they moved to the left. Microsaccades may be modulated by attention and appear functionally related to saccadic intrusions. Pupil-size increased proportionally with the lead up to the instance of the penalty being kicked, reaching a plateau at final movement initiation. In conclusion, microsaccades and small saccades could improve the perception of the soccer penalty kick, helping athletes during the period that precedes the critical movement initiation, shifting from covert to overt attention for identifying the useful cues necessary to guide the action.

Section: Discussionmentioning

confidence: 99%

Understanding the underlying mechanisms of Quiet Eye: The role of microsaccades, small saccades and pupil‐size before final movement initiation in a soccer penalty kick

Piras

Timmis

European Journal of Sport Science

et al. 2020

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“…Microsaccades are small eye movements produced during attempted fixations. In past decades, studies on microsaccades have successfully demonstrated their role in contrasting visual fading [ 11 , 12 ], driving attentional and discrimination tasks [ 13 , 14 , 15 , 16 , 17 ], and processing the visual field [ 18 , 19 , 20 , 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

“…In a previous study, we used optic flow stimuli to reveal the relationship between heading perception and microsaccades in a discrimination task. The results demonstrated that microsaccades’ characteristics and directions are related to heading perception [ 20 ]. In the present work, we moved on to analyze the microsaccades’ characteristics during the view of radial optic flow stimuli with different dot speeds.…”

Section: Introductionmentioning

confidence: 99%

Optic Flow Speed and Retinal Stimulation Influence Microsaccades

Raffi

Meoni

et al. 2022

IJERPH

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Microsaccades are linked with extraretinal mechanisms that significantly alter spatial perception before the onset of eye movements. We sought to investigate whether microsaccadic activity is modulated by the speed of radial optic flow stimuli. Experiments were performed in the dark on 19 subjects who stood in front of a screen covering 135 × 107° of the visual field. Subjects were instructed to fixate on a central fixation point while optic flow stimuli were presented in full field, in the foveal, and in the peripheral visual field at different dot speeds (8, 11, 14, 17, and 20°/s). Fixation in the dark was used as a control stimulus. For almost all tested speeds, the stimulation of the peripheral retina evoked the highest microsaccade rate. We also found combined effects of optic flow speed and the stimulated retinal region (foveal, peripheral, and full field) for microsaccade latency. These results show that optic flow speed modulates microsaccadic activity when presented in specific retinal portions, suggesting that eye movement generation is strictly dependent on the stimulated retinal regions.

“…The great majority of the studies on microsaccades and visual perception have been performed using attentional, cued or discrimination tasks using classical visual stimuli (i.e., small bars either steady or moving across the screen), leading to a large agreement that microsaccades rates are modulated by both endogenous and exogenous attentional shifts [28]. A previous study firstly used optic flow stimuli to uncover the relationship between microsaccades and heading perception in a discrimination task, showing that microsaccade characteristics and directions are related to the correct perception of heading [37]. In the present work, we moved forward, analyzing the microsaccade characteristics during the view of radial optic flow stimuli, given that such stimuli attract attention toward the focus of expansion [38].…”

Section: Introductionmentioning

confidence: 99%

Sensory Input Modulates Microsaccades during Heading Perception

Raffi

Perazzolo

et al. 2021

IJERPH

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Microsaccades are small eye movements produced during attempted fixation. During locomotion, the eyes scan the environment; the gaze is not always directed to the focus of expansion of the optic flow field. We sought to investigate whether the microsaccadic activity was modulated by eye position during the view of radial optic flow stimuli, and if the presence or lack of a proprioceptive input signal may influence the microsaccade characteristics during self-motion perception. We recorded the oculomotor activity when subjects were either standing or sitting in front of a screen during the view of optic flow stimuli that simulated specific heading directions with different gaze positions. We recorded five trials of each stimulus. Results showed that microsaccade duration, peak velocity, and rate were significantly modulated by optic flow stimuli and trial sequence. We found that the microsaccade rate increased in each condition from trial 1 to trial 5. Microsaccade peak velocity and duration were significantly different across trials. The analysis of the microsaccade directions showed that the different combinations of optic flow and eye position evoked non-uniform directions of microsaccades in standing condition with mean vectors in the upper-left quadrant of the visual field, uncorrelated with optic flow directions and eye positions. In sitting conditions, all stimuli evoked uniform directions of microsaccades. Present results indicate that the proprioceptive signals when the subjects stand up creates a different input that could alter the eye-movement characteristics during heading perceptions.