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* <cite>Ripoll-Latiri-1997</cite>
* <cite>Ripoll-Latiri-1997</cite>
* <cite>Senot-2005</cite>
* <cite>Senot-2005</cite>
* Flash-lag in depth <cite>Harris-2006</cite>: Using difference types of motion in depth they found mean precisions about 55-71 ms. The individual differences, however, are very big.  
* Flash-lag in depth <cite>Harris-2006</cite>: Using different types of motion in depth they found mean precisions about 55-71 ms. The individual differences, however, are very big.  

Revision as of 00:09, 14 October 2008


Alex Holcombe
Sarah McIntyre
Fahed Jbarah
• Shih-Yu Lo
• Patrick Goodbourn
Lizzy Nguyen

action precision
Tactile Motion
Tactile Receptors
Binding, grouping


Skills Checklist
Python Programming
Psychopy/VisionEgg Installation Notes
R analysis,plot,stats
Verifying timing
Programming Cheat Sheets

  • cricket:[1] They explored the shot called "back leg glance" in which the trajectory of the ball is perpendicular to the trajectory of the bat. In that way, they can calculate precision just by considering the width of the bat. The temporal resolution of best cricket players is 2 ms. For normal subjects is about 5-10 ms. They think that the precision is not qualitatively different. How can this temporal resolution be achieved?
  • Hopkins and Kristofferson[2] required subjects to generate a time interval by trying to press a button at a precise time after a light went on. After 70000 trials the standard deviation was only 7 ms!
  • ping-pong [1] "managed to get 75% of the balls, on average, into the target area. Because the target had a diameter of 55 cm and was located some 2.5 m away from the point of contact (near the leading edge of the table), this implies that at least 75% of the balls have been contacted with the direction of travel of the bat not varying more than 6° around the line through the center of the target. Assuming a normal distribution, the standard deviation of the direction of travel of the bat at the moment of contact must have been therefore 5.2°. As seen later, angular bat velocities at contact of 800°/s are quite common, which means that the players have to time their moment of contact with a precision of, at maximum, 5.2/0.800 = 6.5 ms"
  • ball falling from ceiling [3] ball dropped down vertical chute. Subject had to swing bat horizontally through line of flight of ball. Plotting successful hit rate against bat width. Showed that ordinary people without any particular practice executed the action within +/- 10msec 90% of the time
  • [4] need this one
  • infants can reach for moving objects with 50 ms precision! [5]
  • less-ecological using mouse to move cursor to intercept object moving in circular trajectory [6]Target (small disc) following a circular path with constant velocity. Design: 2 (real vs apparent motion) x 5 (velocity) within Ss. Ss had to move a mouse cursor to intercept the disc at the 12 o'clock position. For all conditions, Ss intercepted late. Error increased for faster speeds, with a sharp increase for fastest speed (540 deg/s). Precision (SD in deg) was overall worse for apparent motion than for real motion. Precision worsened as a linear function of speed, which means it is more or less constant in time. From their linear regression equations, for real motion it was around 38-47ms, for apparent motion it was 73-91ms. I don't think Ss had to fixate. They got online feedback about the mouse cursor – it would be a pretty meaningless task if they didn't since you can't assume any pre-existing knowledge about how much kinaesthetic motion corresponds to cursor motion on the screen.
  • [7]
  • [8]
  • Flash-lag in depth [9]: Using different types of motion in depth they found mean precisions about 55-71 ms. The individual differences, however, are very big.


  1. McLeod P and Jenkins S. Timing accuracy and decision time in high-speed ball games. International Journal of Sport Psychology 1991; 22 279-295. [McLeod-Jenkins-1991]
  2. Hopkins and Kristofferson. Ultrastable stimulus-response latencies: acquisition and stimulus control. Perception and psychophysics, 27, 241-250. [Hopkins-Kristofferson-1980]
  3. McLeod, P., McLaughlin, C. and Nimmo-Smith, I., 1985. Information encapsulation and automaticity evidence from the visual control of finely timed actions. In: Posner, M.I. and Marin, O.S., Editors, 1985. Attention and performance XI, Erlbaum, Hillsdale, NJ. [McLeod-McLaughlin-NimmoSmith]
  4. McLeod P. Visual reaction time and high-speed ball games" Perception 1987; 16(1) 49 – 59 [McLeod-1987]
  5. von Hofsten, C. (1987). Catching. In H. Heuer & A. F. Sanders (Eds.), Perspectives on perception and action (pp. 33-46). Hillsdale,NJ Erlbaum [vonHofsten-1987]
  6. Port NL, Pellizzer G, Georgopoulos AP. Intercepting real and path-guided apparent motion targets. Exp Brain Res. 1996;110:298-307. [Port-etal-1996]
  7. Ripoll H and Latiri I. . pmid:9486434. PubMed HubMed [Ripoll-Latiri-1997]
  8. Senot P, Zago M, Lacquaniti F, and McIntyre J. . pmid:16120661. PubMed HubMed [Senot-2005]
  9. Harris, LR, Duke, AP, Kopinska, A. Flash-lag in depth. Vision Research, 46, 2735-2742. [Harris-2006]
  10. Bootsma RJ, van Wieringen PCW. Timing an attacking forehand drive in table tennis. Journal of Experimental Psychology: Human Perception and Performance. 1990;16:21 [Bootsma-Wieringen-1990]
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