Neurophilosophy

ATHLETES who are on a winning streak often claim that they perceive their targets to be bigger than they actually are. After a run of birdies, for example, golfers sometimes say that the cup appeared to be the size of a bucket, and baseball players who have a hit a few home runs say that the ball is the size of a grapefruit. Conversely, targets are often reported to be smaller than they actually are by athletes who are performing badly.

Research carried out in the past 5 years suggests that these are more than just anecdotes, and that performance in sports can actually affect perception. A new study by psychologists at Purdue University now lends more weight to this, by providing evidence that success rate in American football field goals affects how the size of the goal posts is perceived.

Jessica Witt and her colleagues have been investigating perception in athletes fro a number of years. Earlier work by this group of researchers has shown that apparent ball size is correlated with batting average in softball players, so that players who are performing better perceive the ball to be bigger, and that golfers who play better judge the hole to be bigger than those who do not play as well.  

For this new study, Witt collaborated with former National Football League player Travis Dorsch. 23 participants were taken to an indoor football practice field, where they warmed up with three practice kicks. They were then asked to estimate how many kicks out of 10 they would score, and also to estimate the dimensions of the field goal posts, using a scaled-down adjustable model made out of PVC pipes (below left). Each participant then kicked 10 field goals, after which they were asked to make another estimate of the height and width of the posts, using the same apparatus.

field goal perception.JPG

It was found that participants who made 3 or more successful kicks perceived the goal to be bigger than it actually was, whereas those who scored 2 or less goals perceived it to be smaller. There was also a relationship between the subsequent perception of the goal posts and how the kicks were missed: participants who more frequently kicked the ball to the left or right of the target perceived the upright posts to be narrower, whereas those whose kicks tended to fall short of the goal, or to be too low, perceived the crossbar to be higher.

There are number of possible explanations for these findings. One is that there is a relationship between the participants’ prediction of their success rate and their perception of goal size, so that those who predcited more successful kicks perceived the goal to bigger, but this was found not to be the case. Alternatively, there may have been pre-existing differences in the participants’ perceptions of the goal posts, and the earlier studies of golfers and softball players had not ruled this out, because the participants had only been asked to estimate target size after performing the task. This time though, the participants were asked to make their estimates twice – once just before their 10 field goal kicks, and again immediately afterwards. The pre-kicking estimates of those who scored 2 kicks or less were no different from those who scored 3 or more, strongly suggesting that the differences in the second estimate of goal size were due to performance on the task.

This is the latest in a series of studies showing that our perceptions are grounded firmly in our actions. Witt’s group has previously demonstrated that perceptions of goal size in golfers and softball players are apparently affected by performance. Other researchers have shown that perception is also influenced by the amount of effort required to perform an action. A location seems further away when one has to walk uphill to reach it, or if one is tired or in pain during the walk, and hills look steeper when one is carrying a heavy backpack. Similarly, objects that are just out of reach are perceived to be closer when one is holding atool that extends reach, while those that are positioned so that they are difficult to grasp are perceived as beign further away.

All of these studies show that perception does not merely involve reconstructing the geometry of one’s environment from visual information. Rather, our perceptions seem to be firmly grounded in, and strongly influenced by, the abilities, intentions and efforts of the perceiver. This may be because we view the environment in terms of energy costs, and plan our actions accordingly. Thus, a tired walker who perceives a hill to be steeper than it actually is will walk more slowly, and an athelete who perceives a target to be bigger will need to expend less energy and attention. Conserving energy is vital for survival, so such an adaptation would confer an important evolutionary advantage.

Related:


Witt, J. K, & Dorsch, T. (2009). Kicking to bigger uprights: Field goal kicking performance influences perceived size. Perception 38: 1328-1340 DOI: 10.1068/p6325.

Witt, J. K. et al. (2008). Putting to a bigger hole: Golf performance relates to perceived size. Psychon. Bull. Rev. 15: 581-585. [PDF]

Witt, J. K. & Proffitt, D. R. (2005). See the ball, hit the ball: Apparent ball size is correlated with batting average. Psychological Sci. 16: 937-938. [PDF]

Comments

  1. #1 Buljung
    October 13, 2009

    thanks for your sharing

  2. #2 Jordi
    October 13, 2009

    I wonder if it is really perception that is affected or just the higher level reasoning that leads to the size estimation. If I approximately know my skill level and I know that I don’t know the size of the goal, it seems likely to take the number of times I score into account when making a size estimation.

    If I score more than I expected, it can be either due to the fact that my skill level is fluctuating (I’m having a good run), or the goal is larger than expected. Or both. Simple reasoning will likely lead me to estimating the goal as larger.

  3. #3 Eric Thomson
    October 13, 2009

    Very cool! Too bad it isn’t perception that drives performance, as then we could use psychophysical tricks to make the goals appear bigger (at least for the Patriots’ kicker, for the Jets we would use tricks to make the goals appear smaller).

  4. #4 NM
    October 13, 2009

    Isn’t this the equivalent of saying that the more times one fails, the harder success would seem to be?

  5. #5 Mo
    October 13, 2009

    NM: Exactly!

  6. #6 Qokhum
    October 14, 2009

    thanks for your sharing

  7. #7 John H.
    November 21, 2009

    These studies, which are published, of course, in a literatury way are quite insight full. May I thank you for your contribution to my knowledge and, paradoxically (maybe! :D oh, this is just me being silly :))), to my emotions also.
    P.S.: The part about the emotions is true, although I will admit that the possibility of a study being quite necessary for the accurate determination of this state of facts is not very unlikely.

  8. #8 Andrew Wilson
    June 30, 2010

    @Jordi This really is about perception. While there is always a problem drawing too strong a conclusion from judgment studies like these, it maps nicely onto Gibson’s claim that what we perceive are affordances. As this post puts it, we don’t simply ‘reconstruct the [Euclidean] geometry’ of the world; instead, we perceive the world in terms of what actions we can take.

    Asking people to judge the objective size of the goal posts is only going to be correlated with what people are actually perceiving, so these studies are always noisy; but it’s clear in the literature that action calibrates perception which drives action and back again, and these are nice demonstrations.

The site is currently under maintenance and will be back shortly. New comments have been disabled during this time, please check back soon.