Limits...
Gaze behavior in one-handed catching and its relation with interceptive performance: what the eyes can't tell.

Cesqui B, Mezzetti M, Lacquaniti F, d'Avella A - PLoS ONE (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy; Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy.

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.

No MeSH data available.


Related in: MedlinePlus

Pursuit accuracy parameters variation across experimental conditions.Top row: smooth pursuit gain parameter averaged for each subject and experimental condition (mean ± SE) is plotted with respect to the initial vertical angular ball velocity at launch. Data are illustrated separately for the two different arrival heights (right column: Z2, left column: Z1). Bottom row: the eye-ball positional lag parameter (TAU). The different subjects and the four different flight duration conditions are coded as in Fig. 6.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4368737&req=5

pone.0119445.g010: Pursuit accuracy parameters variation across experimental conditions.Top row: smooth pursuit gain parameter averaged for each subject and experimental condition (mean ± SE) is plotted with respect to the initial vertical angular ball velocity at launch. Data are illustrated separately for the two different arrival heights (right column: Z2, left column: Z1). Bottom row: the eye-ball positional lag parameter (TAU). The different subjects and the four different flight duration conditions are coded as in Fig. 6.

Mentions: The interaction term between the T and Z fixed effects was significant (p < 0.01) in the case of LTs1. In fact, depending on the ball arrival height, there was a different dependence of LTs1 on flight duration. For example, in the Z2 condition (high) LTs1 increased as the ball flight duration increased, while in the Z1 condition (low) LTs1 showed a more variable behavior (see Fig. 8 top panels). In the case of high launches subjects appeared to initiate pursuit in advance when facing faster balls (i.e. T1 and T2 conditions) with respect to slower conditions (i.e. T3 and T4 conditions). The amplitude of the first saccade was also modulated by ball flight conditions (Fig. 8 bottom panels). Subjects significantly increased the amplitude as flight duration and ball arrival height increased (βT > 0, βZ > 0, both significant). In fact, longer and higher ball trajectories presented also higher initial elevation angular velocities (Fig. 6), which in turn led to larger initial saccadic movements. For this reason data in Figs 8, 9, and 10 are plotted against the initial ball gaze elevation velocity. Differences across subjects were also observed in the distribution of these parameters. They will be described below in a dedicated subsection.


Gaze behavior in one-handed catching and its relation with interceptive performance: what the eyes can't tell.

Cesqui B, Mezzetti M, Lacquaniti F, d'Avella A - PLoS ONE (2015)

Pursuit accuracy parameters variation across experimental conditions.Top row: smooth pursuit gain parameter averaged for each subject and experimental condition (mean ± SE) is plotted with respect to the initial vertical angular ball velocity at launch. Data are illustrated separately for the two different arrival heights (right column: Z2, left column: Z1). Bottom row: the eye-ball positional lag parameter (TAU). The different subjects and the four different flight duration conditions are coded as in Fig. 6.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4368737&req=5

pone.0119445.g010: Pursuit accuracy parameters variation across experimental conditions.Top row: smooth pursuit gain parameter averaged for each subject and experimental condition (mean ± SE) is plotted with respect to the initial vertical angular ball velocity at launch. Data are illustrated separately for the two different arrival heights (right column: Z2, left column: Z1). Bottom row: the eye-ball positional lag parameter (TAU). The different subjects and the four different flight duration conditions are coded as in Fig. 6.
Mentions: The interaction term between the T and Z fixed effects was significant (p < 0.01) in the case of LTs1. In fact, depending on the ball arrival height, there was a different dependence of LTs1 on flight duration. For example, in the Z2 condition (high) LTs1 increased as the ball flight duration increased, while in the Z1 condition (low) LTs1 showed a more variable behavior (see Fig. 8 top panels). In the case of high launches subjects appeared to initiate pursuit in advance when facing faster balls (i.e. T1 and T2 conditions) with respect to slower conditions (i.e. T3 and T4 conditions). The amplitude of the first saccade was also modulated by ball flight conditions (Fig. 8 bottom panels). Subjects significantly increased the amplitude as flight duration and ball arrival height increased (βT > 0, βZ > 0, both significant). In fact, longer and higher ball trajectories presented also higher initial elevation angular velocities (Fig. 6), which in turn led to larger initial saccadic movements. For this reason data in Figs 8, 9, and 10 are plotted against the initial ball gaze elevation velocity. Differences across subjects were also observed in the distribution of these parameters. They will be described below in a dedicated subsection.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy; Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy.

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.

No MeSH data available.


Related in: MedlinePlus