Alessandro Piras

Prof. Alessandro Piras

Dipartimento di Scienze per la Qualità della Vita, Alma Mater Studiorum Università di Bologna, Bologna, Emilia-Romagna, Italy
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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 April 2014 in Journal of Ophthalmology
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Journal Article
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Alessandro PirasAlessandro Piras
Alessandro Piras
RLRoberto Lobietti
Roberto Lobietti
SSSalvatore Squatrito
Salvatore Squatrito
This paper aimed at comparing expert and novice volleyball players in a visuomotor task using realistic stimuli. Videos of a volleyball setter performing offensive action were presented to participants, while their eye movements were recorded by a head-mounted video based eye tracker. Participants were asked to foresee the direction (forward or backward) of the setter’s toss by pressing one of two keys. Key-press response time, response accuracy, and gaze behaviour were measured from the first frame showing the setter’s hand-ball contact to the button pressed by the participants. Experts were faster and more accurate in predicting the direction of the setting than novices, showing accurate predictions when they used a search strategy involving fewer fixations of longer duration, as well as spending less time in fixating all display areas from which they extract critical information for the judgment. These results are consistent with the view that superior performance in experts is due to their ability to efficiently encode domain-specific information that is relevant to the task.

1 February 2014 in International Journal of Sports Science & Coaching
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Journal Article
Closed access
Alessandro PirasAlessandro Piras
Alessandro Piras
EPEmanuela Pierantozzi
Emanuela Pierantozzi
SSSalvatore Squatrito
Salvatore Squatrito
Visual search behaviour is believed to be very relevant for athlete performance, especially for sports requiring refined visuo-motor coordination skills. Modern coaches believe that optimal visuo-motor strategy may be part of advanced training programs. Gaze behaviour of expert and novice judo fighters was investigated while they were doing a real sport-specific task. The athletes were tested while they performed a first grip either in an attack or defence condition. The results showed that expert judo fighters use a search strategy involving fewer fixations of longer duration than their novice counterparts. Experts spent a greater percentage of their time fixating on lapel and face with respect to other areas of the scene. On the contrary, the most frequently fixed cue for novice group was the sleeve area. It can be concluded that experts orient their gaze in the middle of the scene, both in attack and in defence, in order to gather more information at once, perhaps using parafoveal vision.

22 June 2017 in Journal of Sports Sciences
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Journal Article
Closed access
Alessandro PirasAlessandro Piras
Alessandro Piras
Milena RaffiMilena Raffi
Milena Raffi
MPMonica Perazzolo
Monica Perazzolo
ILIvan Malagoli Lanzoni
Ivan Malagoli Lanzoni
SSSalvatore Squatrito
Salvatore Squatrito
Microsaccades are important fixation eye movements for visual scene perception. Compared to novices, athletes make fewer fixations of longer duration toward limited interest areas crucial for action prediction. Thus, our aim was to study the microsaccade features during those fixations. Gaze behaviour of expert and novice table tennis players was recorder during a task in which subjects were instructed to predict the direction of the ball after the opponent’s throw. Three interest areas from the opponent’s body and one from the ball trajectory were identified. We analysed correctness of predictions, fixations, microsaccades and saccades to estimate the relationship between eye movements toward interest areas and success in the task. Compared to novices, experts fixated more on hand-racket during forehand and on trunk during backhand drive technique. Longer fixations on hand-racket and trunk were associated with higher microsaccade rate with a narrower directional distribution of them. It probably means that athletes focused their gaze on these small areas, suggesting enhanced attention mainly to them, and fewer consideration for the surrounding regions. We can assume that microsaccade rate and average direction could be related to the salience of interest areas during performance.

1 November 2016 in The American Journal of Geriatric Psychiatry
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Journal Article
Closed access
GTGiulio Toni
Giulio Toni
MMMartino Belvedeti Murri
Martino Belvedeti Murri
MPMassimo Piepoli
Massimo Piepoli
SZStamatula Zanetidou
Stamatula Zanetidou
ACAderville Cabassi
Aderville Cabassi
MAMario Amore
Mario Amore

1 July 2015 in Investigative Ophthalmology & Visual Science
Verified
Journal Article
Open access
PDF file
Alessandro PirasAlessandro Piras
Alessandro Piras
Milena RaffiMilena Raffi
Milena Raffi
ILIvan Malagoli Lanzoni
Ivan Malagoli Lanzoni
MPMichela Persiani
Michela Persiani
SSSalvatore Squatrito
Salvatore Squatrito
Purpose: Microsaccades could indicate the place where our mind is unconsciously focusing, although our gaze is directed elsewhere. Many studies report the importance of microsaccades in visual scene perception, but none of them has addressed their relationship with the perception of a dynamic action and the prediction of its outcome. Methods: Expert and novice table tennis players were asked to fixate their gaze on a precise spot while viewing the launch of a ball whose final landing had to be predicted. Four separate epochs of the action were considered for their information content. The correctness of the prediction and microsaccade statistics were measured in order to estimate the relationship between covert attention and predictions. Results: Microsaccades rate showed a time course modulated by the different epochs, with a significant enhancement during the post-bounce. In this epoch, novices showed a significantly higher rate than experts when the responses were correct. Duration and amplitude were highest in the pre- and post-bounce periods and lowest in the other two. Mean microsaccades direction was toward the stimuli that most probably attracted the visual attention (ball or racket), whereas there was no relationship with the predicted side of the final bounce. Conclusions: Distribution of microsaccades can be influenced by attentional cues in a task-specific situation, revealing links between visuomotor performance and covert attention shifts in fast visuomotor perception. Microsaccade orientation is conditioned by objects that attract visual attention and not by the direction in which action is expected to be performed.