ANTICIPATION

Learning objectives understand what is meant by interceptive actions understand how information processing theory explains interceptive actions understand how action systems theory explains interceptive actions understand the nature and role of perceptual anticipation in skilled performance understand how information processing theory explains perceptual information understand how action systems theory explains perceptual anticipation understand the difficulties of carrying out research into anticipation understand the main research findings into anticipation have a basic knowledge of the key developmental issues

Interceptive actions Hitting a tennis ball, kicking a soccer ball or catching a netball are all examples of interceptive actions Punching someone in boxing is an interceptive action Avoiding interception is a form of interceptive action e.g. avoiding a punch in boxing

Information processing theory and interceptive actions Poulton (1957) called the making of interceptive actions coincidence anticipation Coincidence anticipation = effector anticipation plus receptor anticipation Effector anticipation refers to how long the individual thinks it will take them to move their limbs in order to make the interception Receptor anticipation is how long the person thinks that it will take for an external event to happen It is a working memory task Depends greatly on LTM store of similar situations Pattern recognition plays a major role

Action systems theory and interceptive actions Light waves from the person’s eyes to the object to be intercepted and back again provide information about the line and speed of flight We subconsciously ‘calculate’ tau () or time to contact The rate at which the size of the image of the object on the retina increases provides all the necessary information to calculate Lee (1976) showed that the inverse of the relative rate of expansion of the retinal image gives an accurate measure of  When contact is imminent, the object provides an affordance to make or avoid contact Perception-action coupling allows the interception to be made or avoided

Criticisms of the  hypothesis The  hypothesis is based on the assumption that the speed of the approaching object is constant In real life, it is not It normally slows due to various resistances in the atmosphere Lee claimed that the individual automatically takes this into account and, in such situations, determines what he calls tau dot (̇ ) ̇ is the rate of change in  itself the person does not calculate  once but does so ‘on-line’, i.e. calculates the continuous rate of change in 

Catching ‘skyers’ and ‘fly balls’ Michaels and Oudejans (1992) claimed that fielders aim to maintain a ‘constant bearing angle’ between their head and the ball This eases the calculation of ̇ As we do not catch with our eyes, a late second interceptive movement is necessary in order to get the hands or glove into position to make the catch Lenoir et al. (1999) claimed that fielders attempt to maintain a constant bearing angle between the hands (or catching mitt) and the ball Thus only one calculation is needed When the ball is to be intercepted by say a racquet, as in tennis, or a foot, as in soccer, the bearing angle is kept between the racquet (or foot) and ball López-Moliner et al. (2007) claimed that  and ̇ are supplemented by knowledge of the object to be intercepted

Perceptual anticipation Perceptual anticipation is the ability of the performer to predict upcoming events based on partial information It is vital in situations that require a decision to be made in faster than one reaction time It also plays a major role in the way we make decisions when not under time pressure Allows us to plan ahead

Information processing theory and perceptual anticipation A working memory task Relies on large LTM store Pattern recognition is very important

Ecological psychology and perceptual anticipation All necessary information is in the environment Biomechanical information allows pattern recognition Affordances are present These are obvious as long as we know the aims of the game We do become attuned to these affordances through practice

Research paradigms in perceptual anticipation Temporal occlusion Comparison of experts and novices watching videos and having to decide what was going to happen when the video is stopped before or just after a key point (e.g. racquet-ball contact when watching a serve in tennis) Spatial occlusion Comparison of experts and novices watching videos and having to decide what was going to happen when body parts or equipment (e.g. the racquet in badminton) are occluded Participants have to mark on a map where they think the ball would have landed Some paradigms have the participant make a simulated movement

Visual search research paradigms in perceptual anticipation Tracking eye movements of experts and novices while they watch a video and have to make an anticipatory decision at a chosen point Eye-mark (or eye-tracking) recorders are worn Can be used in real life situations Scan paths, fixation locations and durations can be measured Dependent variables can be verbal or motor (make some kind of movement)

Research results Very early cues can be used to aid anticipation Often pre-ball release/contact by an opponent Decisions are not always ‘all or nothing’ but the person continues to monitor the situation and make changes ‘on-line’ Experts better than novices, and to lesser extent intermediate level performers, when using the early cues Expert-novice differences in number of fixations on key parts of the display, scan paths and lengths of time focusing on key points Experts better in real life situations than in video simulations

Development and anticipation: interceptive actions By eight months infants catch objects moving along the ground at 125 cm/s Changes in infancy are due to developments in the sensory and motor cortices, and physical development Later changes are greatly affected by experience By 3 years children can make a catch using arms and body By 5 years children can catch a small ball using hands only By 6 years they are capable of producing a mature catching action By 6-7 years the child can hit a stationary ball with a mature pattern Age at being able to hit a moving ball depends on experience and varies greatly

Development and anticipation: perceptual anticipation Information Processing theorists and ecological psychologists agree that ability is dependent on cognitive development and experience According to Information Processing theorists, everything is dependent on Working memory LTM store According to ecological psychologists everything is dependent on Attunement to affordances