Elite motor expertise refines estimation of temporal events

The general aim of this research was to broaden the knowledge about the highly developed perceptual and motor system possessed by elite athletes and professional pianists by focusing the attention on their ability to evaluate the passage of time. That is, we sought to identify motor expert’s superiority in evaluating temporal events as compared to non-motor experts specifically on the timescale below and above a second. This specific range of time selected is considered crucial for achieving exceptional motor performances in sports and in music playing (review see Buhusi & Meck, 2005). In Study 1 titled “Elite athletes refine their internal timers”, elite athletes (fencers and pole-vaulters) and non-athletes were recruited as participants. We first attacked a long-debated issue by asking whether a single centralized internal clock (e.g., Creelman, 1962; Treisman, 1963) or two separate timing mechanisms (e.g., Lewis & Miall, 2003) are better articulated in describing participants’ reproductions of time instants from hundreds of milliseconds to more than a second. The proficiency of temporal estimates, as accuracy and precision, was compared between elite athletes and non-athletes. As a secondary issue, the effect on the type of skill developed, namely open versus closed skill in which an athlete’ movements are externally- or self-paced, was investigated by comparing the performance of elite fencers (a typical open-skill activity) and elite pole-vaulters (a typical closed-skill activity). Inspired by the notion “representational momentum” (Freyd & Finkie, 1984) that sustains the existence of a dynamic internal embodiment of the observed action, in study 2 titled “Seeing an implicit expertise-related action allows perfect time flow estimation” we investigated how the hypothesized mental representation of an observed action influences time evaluation. Pianists and musically-naïve controls were asked to reproduce different times of exposure of either piano playing or non-music related visual displays, both were presented in an implicit action (as shown in one single photograph) or in an explicit action (as shown in one video-clip) exposed for time shorter or longer than a second. Error and variability were the measures used again to test the level of refinement of internal action simulators provoked by the specificity and dynamical properties of the stimuli presented. In general we found that both motor experts groups (elite athletes and professional pianists) showed a higher timing proficiency with less error and lower variability across trials compared with non-experts. This result confirms that long-term learning/training experience in space/time domain as athletes and musicians possess, could refine individual’s time estimation ability as reported in developmental studies where children have been shown to improve their temporal judgment with age (e.g., Szalag et al., 2002) or in studies that confirmed the short-term (for example 5-days) learning effect (Rammsayer, 1994; Karmarkar & Buonomano, 2003; Perret et al., 1993). More importantly, this higher ability was present independently of the range of time tested (below and above a second). Interestingly though all the participants tested showed a trend of the data that implies the existence of two separated internal clocks (one for below a second range and one for above a second range). This finding then strongly supports the existence of multiple clocks for different ranges of time (e.g., Lewis & Miall, 2003; Buhusi & Meck, 2005) as contrasted to the notion of one central clock taking care of timing behaviour in all timescales (e.g., Gibbon, 1977). An important finding in this research is the confirmation of the tight link between time perception and internal action embodiment. Our results showed that pianists outperformed the controls independently of the time of exposure of the stimuli as found in study 1, but only pianists differentiated the two actions by showing higher timing accuracy for implicit expertise related actions (hand in a piano playing photograph) and lower timing variability for explicit expertise related actions (hand in a piano playing video-clip). The characteristic of embodying an implied action represented in a single photograph is “time free” such that the perceivers determine their own rate in forming the action. Possibly due to a more activated internal action representation (Haslinger et al., 2005), pianists were more able to correctly reproduce the time flow of piano-playing photo expositions. While viewing an explicit action as shown in a video-clip in which a sequence of movements was presented in a certain rate, perceivers appeared to have their internal action embodiment disturbed by the superimposed sequence of action. Therefore, pianists were no longer showing their accuracy superiority for piano-playing as compared to finger-thumb opposition actions even though they were more accurate than controls for both action videos. Nevertheless, the specificity was detected in terms of their estimation variability, suggesting that pianists were more stable in their estimates using a more consistent strategy probably due to more familiarity with piano-playing actions. These two different strategies applied by pianists in performing the task are interpreted based on the idea of internal action embodiment. To sum up, our results broaden the knowledge in time perception specifically below and above a second by investigating motor experts’ capability to perceive temporal events. Moreover, for the first time we provide evidence that throughout perceptual and motor training, experts create a specific internal representation of the movements allowing them to precisely estimate the time flow. Interestingly our data suggest that the operation of internal action embodiment works more efficiently when the perceivers form their movement representations at a preferred rate; future study could investigate in deep this issue by manipulating the movement velocity of an observed action.