Does training with 3D videos improve decision-making in team invasion sports?

We examined the effectiveness of video-based decision training in national youth handball teams. Extending previous research, we tested in Study 1 whether a three-dimensional (3D) video training group would outperform a two-dimensional (2D) group. In Study 2, a 3D training group was compared to a control group and a group trained with a traditional tactic board. In both studies, training duration was 6 weeks. Performance was measured in a pre- to post-retention design. The tests consisted of a decision-making task measuring quality of decisions (first and best option) and decision time (time for first and best option). The results of Study 1 showed learning effects and revealed that the 3D video group made faster first-option choices than the 2D group, but differences in the quality of options were not pronounced. The results of Study 2 revealed learning effects for both training groups compared to the control group, and faster choices in the 3D group compared to both other groups. Together, the results show that 3D video training is the most useful tool for improving choices in handball, but only in reference to decision time and not decision quality. We discuss the usefulness of a 3D video tool for training of decision-making skills outside the laboratory or gym.

Long-term effects of acoustic reafference training (ART).

In sport visual feedback is often used to enhance performance, mostly neglecting the auditory modality. However, athletes produce natural sounds when they move (acoustic reafferences) which they perceive and use to control their movements. We examined the short- and long-term effects of a training intervention on a complex movement by using acoustic reafferences. Natural step sounds produced during hurdling were recorded and played back to the participants immediately before each trial, with an increase (fast group), decrease (slow group), or no manipulation (control group) in the tempo. All groups increased their hurdling performance regarding overall running time, with the slow group showing the best performance development. After a 10-week retention, the fast and slow group further increased performance, whereas the control group declined. The repeated experience with acoustic information associated with the rhythmic pattern of hurdling may have helped developing a cognitive representation of that movement, especially regarding long-term effects.

Auditory reafferences: the influence of real-time feedback on movement control.

Auditory reafferences are real-time auditory products created by a person's own movements. Whereas the interdependency of action and perception is generally well studied, the auditory feedback channel and the influence of perceptual processes during movement execution remain largely unconsidered. We argue that movements have a rhythmic character that is closely connected to sound, making it possible to manipulate auditory reafferences online to understand their role in motor control. We examined if step sounds, occurring as a by-product of running, have an influence on the performance of a complex movement task. Twenty participants completed a hurdling task in three auditory feedback conditions: a control condition with normal auditory feedback, a white noise condition in which sound was masked, and a delayed auditory feedback condition. Overall time and kinematic data were collected. Results show that delayed auditory feedback led to a significantly slower overall time and changed kinematic parameters. Our findings complement previous investigations in a natural movement situation with non-artificial auditory cues. Our results support the existing theoretical understanding of action-perception coupling and hold potential for applied work, where naturally occurring movement sounds can be implemented in the motor learning processes.

The perception of natural and modulated movement sounds.

The motor system is engaged when we perceive movement in the environment, even when we have no sensorimotor experience of that movement. It has been suggested that this ability relies on internal models that comprise specific exteroceptive representations, such as audition and vision. It has been shown that, for human movements, the quality of perception depends on the closeness between the perceived movement and the perceiver's own capability of reproducing it. Thus, if we are able to reproduce a movement, we also have the interoceptive motor memories that enable us to run internal models and perceive the same movements more accurately when merely observed. In a behavioral study we investigated if participants would be able to distinguish between self-produced and other-produced movement sounds from a previously recorded hurdling performance. We also analyzed if participants' discriminative ability would vary as a function of specific sound features, examining rhythmic step structure and amplitude range. The results reveal that participants were able to distinguish between their own and others' movement sounds. However, changing either rhythmic step structure or amplitude range of the sounds did not influence this self-other discrimination. We suggest that identification of one's own movement sounds is holistically achieved as an auditory gestalt.

Recognising one's own motor actions through sound: the role of temporal factors.

It has been shown that humans are able to recognise their own movement. While visual cues have been amply studied, the contribution of auditory cues is not clear. Our aim was to investigate the role of temporal auditory cues in the identification of one's own or others' performance in a complex movement--a golf swing. We investigated whether golfers are able to discriminate between the sounds associated with their own swings and other golfers' swings, by using the relative timing and the overall duration of the movement. The sounds produced by the participants performing 65 m shots have been recorded and used to create the stimuli. The experimental conditions were: participants' swing sounds and the sounds of other golfers having equal both relative timing and overall duration, equal relative timing but different overall duration, different relative timing but equal overall duration, and both different relative timing and overall duration. The task of the participants was to say whether each sound corresponded or did not correspond to their own swing. Results show that golfers are able to recognise their own movements, but they also recognise as their own the sound produced by other athletes having equal both relative timing and overall duration.

Motor familiarity: brain activation when watching kinematic displays of one's own movements.

The perception of action is influenced by the observer's familiarity with its movement. However, how does motor familiarity with own movement patterns modulate the visual perception of action effects? Cortical activation was examined with fMRI while 20 observers were watching videotaped point-light displays of markers on the shoulders, the right elbow, and wrist of an opposing table tennis player. The racket and ball were not displayed. Participants were asked to predict the invisible effect of the stroke, that is, the ball flight direction. Different table tennis models were used without the observers knowing and being informed in advance that some of the presented videos displayed their own movements from earlier training sessions. Prediction had to be made irrespective of the identity of the player represented by the four moving markers. Results showed that participants performed better when observing their "own" strokes. Using a region-of-interest approach, fMRI data showed that observing own videos was accompanied by stronger activation (compared to other videos) in the left angular gyrus of the inferior parietal lobe and the anterior rostral medial frontal cortex. Other videos elicited stronger activation than own videos in the left intraparietal sulcus and right supramarginal gyrus. We suggest that during action observation of motorically familiar movements, the compatibility between the observed action and the observers' motor representation is already coded in the parietal angular gyrus--in addition to the paracingulate gyrus. The activation in angular gyrus is presumably part of an action-specific effect retrieval that accompanies actor-specific prefrontal processing. The intraparietal sulcus seems to be sensitive to incongruence between observed kinematics and internal model representations, and this also influences processing in the supramarginal gyrus.