Role of image acceleration in judging landing location of free-falling projectiles.

Babler, Timothy; Dannemiller, James L.

doi:10.1037/0096-1523.19.1.15

Cited by 57 publications

(100 citation statements)

References 22 publications

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“…Babler & Dannemiller, 1993;Calderone & Kaiser, 1989). The time courses of these two variables are very similar, but there are differences.…”

Section: Resultsmentioning

confidence: 94%

“…Catchers were videotaped, and their running patterns were determined from the digitized video images. Michaels and Oudejans showed that their participants indeed ran in a way that tended to keep optical speed constant throughout the run (optical speed deviated from con-3 Although studies asking observers to judge the future passing side (in front or behind) of (simulated) balls might provide evidence that observers make these judgments on the basis of optical acceleration (e.g., Babler & Dannemiller, 1993;Michaels & Oudejans, 1992), the use of optical acceleration in such a task cannot be generalized to the adherence to a Chapman Strategy, which claims a continuous control of locomotion on the basis of that variable. Later in this article we present further evidence that one needs to study the situation with locomotion to make claims on the use of the variables implied in the control of locomotion.…”

Section: Do Catchers Adhere To the Chapman Strategy?mentioning

confidence: 99%

“…In some cases, we simply refer to optical acceleration or optical velocity to express that we consider the variables in a more general sense without reference to their specific definition. plane, could accurately judge whether these simulated balls passed in front of, behind, or at their position (Babler & Dannemiller, 1993;Michaels & Oudejans, 1992).…”

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confidence: 99%

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The information for catching fly balls: Judging and intercepting virtual balls in a CAVE.

Zaal¹,

Michaels²

2003

Journal of Experimental Psychology: Human Perception and Perfor

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Visually guided action implies the existence of information as well as a control law relating that information to movement. For ball catching, the Chapman Strategy-keeping constant the rate of change of the tangent of the elevation angle (d(tan(␣))/dt)-leads a catcher to the right location at the right time to intercept a fly ball. Previous studies showed the ability to detect the information and the consistency of running patterns with the use of the strategy. However, only direct manipulation of information can show its use. Participants were asked to intercept virtual balls in a Cave Automated Virtual Environment (CAVE) or to judge whether balls would pass behind or in front of them. Catchers in the CAVE successfully intercepted virtual balls with their forehead. Furthermore, the timing of judgments was related to the patterns of changing d(tan(␣))/dt. The advantages and disadvantages of a CAVE as a tool for studying interceptive action are discussed.The visual guidance of goal-directed movement implies the existence of information for controlling that movement as well as a control law expressing the relation between this information and the forces to be exerted by the organism to realize that movement. It is the task of the student of perception-action to discover both the implied information and the control laws for the task under study. For the specific task of catching a fly ball, some progress has been made in identifying the information as well as the control law associated with this information. In this article we argue, however, that not all alternatives have been ruled out by previous studies. To provide an unequivocal test of whether the rate of change of the tangent of the elevation angle (or, equivalently, optical acceleration; definitions are given below) is the information used in fly-ball catching, we performed experiments using virtual reality techniques while at the same time assessing the usefulness of virtual reality for the study of perception-action tasks such as catching fly balls.Most of the theoretical work on the interception of fly balls bears at least some relation to the proposal made by the physicist Seville Chapman in 1968. He considered the situation in which a ball travels along the sagittal plane toward a fielder. Chapman ignored the effects of air resistance (drag) on the ball and consequently assumed that the ball would follow a parabolic path. His mathematical analysis showed that the tangent of the angle of elevation, defined as the angle ␣ between the horizontal and the line connecting the ball with the point of observation, increases at a constant rate if the ball will land exactly at the point of observation. A constant optical velocity, that is, a constant d(tan(␣))/dt, will also occur if a catcher runs at a constant speed to arrive at the landing location of the ball at the same time as the ball does. An increasing d(tan(␣))/dt specifies that the ball will fly over the catcher's head. To catch the ball, the catcher should start running backward or, if he or she is alr...

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“…Babler & Dannemiller, 1993;Calderone & Kaiser, 1989). The time courses of these two variables are very similar, but there are differences.…”

Section: Resultsmentioning

confidence: 94%

Section: Do Catchers Adhere To the Chapman Strategy?mentioning

confidence: 99%

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The information for catching fly balls: Judging and intercepting virtual balls in a CAVE.

Zaal¹,

Michaels²

2003

Journal of Experimental Psychology: Human Perception and Perfor

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“…In the second experiment, we used an indirect interceptive task in which participants intercepted a moving stimulus using a ball 3 Some recent studies have tried to test Chapman's (1968) hypothesis, according to which locomotor displacements required to catch a ball in flight could depend directly on the perception of the acceleration of the ball (e.g., Babler & Dannemiller, 1993;Brouwer et al, 2002;P. McLeod, Reed, & Dienes, 2001;Michaels & Oudejans, 1992;Oudejans, Michaels, Bakker, & Davids, 1999).…”

Section: Synthesismentioning

confidence: 99%

Time-to-Contact Estimation of Accelerated Stimuli Is Based on First-Order Information.

Ripoll¹,

Broderick²

2003

Journal of Experimental Psychology: Human Perception and Perfor

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The goal of this study was to test whether 1st-order information, which does not account for acceleration, is used (a) to estimate the time to contact (TTC) of an accelerated stimulus after the occlusion of a final part of its trajectory and (b) to indirectly intercept an accelerated stimulus with a thrown projectile. Both tasks require the production of an action on the basis of predictive information acquired before the arrival of the stimulus at the target and allow the experimenter to make quantitative predictions about the participants' use (or nonuse) of 1st-order information. The results show that participants do not use information about acceleration and that they commit errors that rely quantitatively on 1st-order information even when acceleration is psychophysically detectable. In the indirect interceptive task, action is planned about 200 ms before the initiation of the movement, at which time the 1st-order TTC attains a critical value.

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“…When you follow this heuristic, you will be there when the ball hits the ground. As it happens, baseball players are very poor at predicting where a ball is going to hit the ground when they are asked not to run towards it (Babler & Dannemiller, 1993). They just manage to get there when the ball does.…”

Section: )mentioning

confidence: 99%

The mismeasure of machine: Synthetic biology and the trouble with engineering metaphors

Boudry

Pigliucci

2013

Studies in History and Philosophy of Science Part C: Studies in

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a b s t r a c tThe scientific study of living organisms is permeated by machine and design metaphors. Genes are thought of as the ''blueprint'' of an organism, organisms are ''reverse engineered'' to discover their functionality, and living cells are compared to biochemical factories, complete with assembly lines, transport systems, messenger circuits, etc. Although the notion of design is indispensable to think about adaptations, and engineering analogies have considerable heuristic value (e.g., optimality assumptions), we argue they are limited in several important respects. In particular, the analogy with human-made machines falters when we move down to the level of molecular biology and genetics. Living organisms are far more messy and less transparent than human-made machines. Notoriously, evolution is an opportunistic tinkerer, blindly stumbling on ''designs'' that no sensible engineer would come up with. Despite impressive technological innovation, the prospect of artificially designing new life forms from scratch has proven more difficult than the superficial analogy with ''programming'' the right ''software'' would suggest. The idea of applying straightforward engineering approaches to living systems and their genomesisolating functional components, designing new parts from scratch, recombining and assembling them into novel life forms-pushes the analogy with human artifacts beyond its limits. In the absence of a one-to-one correspondence between genotype and phenotype, there is no straightforward way to implement novel biological functions and design new life forms. Both the developmental complexity of gene expression and the multifarious interactions of genes and environments are serious obstacles for ''engineering'' a particular phenotype. The problem of reverse-engineering a desired phenotype to its genetic ''instructions'' is probably intractable for any but the most simple phenotypes. Recent developments in the field of bio-engineering and synthetic biology reflect these limitations. Instead of genetically engineering a desired trait from scratch, as the machine/engineering metaphor promises, researchers are making greater strides by co-opting natural selection to ''search'' for a suitable genotype, or by borrowing and recombining genetic material from extant life forms.Ó 2013 Elsevier Ltd. All rights reserved. When citing this paper, please use the full journal title Studies in History and Philosophy of Biological and Biomedical SciencesWe improve our favourite plants and animals-and how few they are-gradually by selective breeding; now a new and better peach, now a seedless grape, now a sweeter and larger flower, now a more convenient breed of cattle. We improve them gradually, because our ideals are vague and tentative, and our knowledge is very limited; because Nature, too, is shy and slow in our clumsy hands. Some day all this will be better organized, and still better. That is the drift of the current in spite of the eddies. The whole world will be intelligent, educated, and co-operating; th...

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Role of image acceleration in judging landing location of free-falling projectiles.

Cited by 57 publications

References 22 publications

The information for catching fly balls: Judging and intercepting virtual balls in a CAVE.

The information for catching fly balls: Judging and intercepting virtual balls in a CAVE.

Time-to-Contact Estimation of Accelerated Stimuli Is Based on First-Order Information.

The mismeasure of machine: Synthetic biology and the trouble with engineering metaphors

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