Final Report Summary - ACTION AND TIME (Perception of Time during Action Preparation) Sensory perception is often regarded as solely based on the characteristics of the sensory input. However, since the action is the only way for humans to interact with the environment, any sensory input should be processed according to the actions we make. The aim of the current project was to elucidate the mechanism of how the sensory input is modified by the neuronal processing of action. As the main part of the project, we tested how the time is perceived during the preparation for action. We developed a novel paradigm where participants were asked to judge the duration of a visual stimulus (white disk) presented on a monitor. The participants judged the duration by responding whether it was “short” in duration or “long” in duration. In the experimental condition, participants prepared for a reaching movement and reached out towards a target disk appeared on the monitor just after the disappearance of the white disk. They then judged the duration of the white disk. In the control condition, participants just judged the duration of the white disk without preparing any movements. Only during the experimental condition, the process of action preparation existed during the duration evaluation period, therefore, this paradigm allowed us to directly assess the effect of action preparation on duration judgment of the visual stimulus. Changing the feature of the visual stimulus also enabled us to assess the impact of action preparation on different aspects of visual processing, thus allowed us to gain deeper understanding of how the action preparation can modulate the perception of time. In summary, it was found that, 1) the visual stimulus is perceived as to last longer when action is prepared; 2) this time dilation effect does not occur when visual detection task is prepared just after the disappearance of the white disk, thus was action preparation specific; 3) the dilation of time depends on the degree of motor preparation (degree of uncertainty about action), thus is tightly linked to the processing of action preparation; 4) action preparation not only acts to prolong the perceived duration of time, but it also slows down the perceived frequency of a flickering stimuli; 5) during action preparation, capacity of visual information processing is increased. From these results, we concluded that action preparation dilates and slows down subjective passage of time, as a consequence of enhanced visual temporal processing. This increase of process capability may come from the strategy of the brain trying to gather as much environmental information as possible before the actual motor execution, to detect any information that alerts stopping or changing of the planned action. This novel finding was published as an article in a scientific journal (Hagura, Kanai, Orgs, Haggard. 2012; http://rspb.royalsocietypublishing.org/content/279/1746/4399.long ). Since this finding confirms the anecdotal feelings of the expert ball players reporting that the “ball slow down before hitting the ball”, the article received significant media interest, and the content was broadcasted inside/ outside of Europe, through TV/ radio programs of United Kingdom, France, Austria, Switzerland, China, Brazil, India etc. e.g. BBC News < http://www.bbc.co.uk/news/science-environment-19477623 >, Le Figaro < http://sante.lefigaro.fr/actualite/2012/09/06/19002-comment-grands-sportifs-arrivent-ralentir-temps >, Austrian Broadcasting Corporation < http://science.orf.at/stories/1704298/ >, CBS News < http://www.cbsnews.com/8301-205_162-57506743/study-time-really-does-slow-for-top-athletes/ >In line with the theme of action-based sensory processing, we have also revealed that delaying the visual feedback information of hand movement can make the movement to be perceived heavier (Honda, Hagura, Yoshioka, Imamizu, 2013 < http://journal.frontiersin.org/Journal/10.3389/fpsyg.2013.00760/full >). Furthermore, it was found that just associating a certain feature of the visual stimulus with the heaviness of movement can make the participants to avoid “seeing” that particular sensory feature (Hagura, Diedrichsen, Haggard, 2013 < http://www.seas.harvard.edu/motorlab/TCMC2013/91.pdf >). Overall, these findings of the project point out that our sensory perception is not a mere result of the sensory processing, but is tightly linked with the processing of action. The perspective focusing the importance of action in “creating” the perception is often referred to as “embodied” perspective, and has a strong philosophical background. Our findings of the project empirically support the “embodied” nature of our sensory perception, therefore, is expected to impact not only to the scientific community, but to the philosophical community. Furthermore, as the study attracted broad media interest, the findings of this project have potential to reveal the sports athlete’s experiences during their performance. Therefore, the study may also provide novel knowledge to the sports science populations, as well as to the wider public, including sports organisations and public sports fans.