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| OCR Specifications 2000. Module 1. Section B: Acquiring, Performing and Teaching Movement Skills |
| AS Level PE - Skill Acquisition |
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| Mr B's scheme of work for Skill Acq (online soon) |
| Info and links in the 'A Level' zone. Check it out!! |
| Reaction Time |
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| Reaction Time: |
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| Reaction time: |
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| Definitions of reaction time (RT), movement time and response time. Awareness of the importance of a short reaction time. Identify the factors affecting response time in practical activities. These should be included in the PPP. Knowledge of the psychological refractory period, choice reaction time (Hick's Law), and the role of anticipation. |
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| 2001 - S J Bettinson at www.physed.co.uk All comments to [email protected] |
| Some psychologists study decision-making by measuring the time between a performer seeing a stimulus and responding to it. This is known as the reaction time (or RT). Reaction time in sport is very important as many activities depend for their success on fast reactions, whether reacting to the starting pistol or responding to an opponent�s �dummy� in rugby. The study of reaction time is also important because it tells us a lot about the process of making decisions. |
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| Commentators in sport often use the term �reaction time� instead of �response time�. Indeed, When we conduct the experiment of an individual catching a vertical ruler that has been dropped, this would be more accurately described as a response time experiment. Look at the diagram below (which shows the whole sequence of responding to a stimulus in the context of a sprint) and the definitions that follow and write down why you think this may the case. |
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| or (Information Processing time) is the time between the presentation of a stimulus and the very start of the movement made in response to it � for example the time taken between the gun going off and the sprinter starting to move. It is, in reality, the time taken to process stimulus information. |
| Reaction time (RT): |
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| the time between starting and finishing a movement. |
| Movement time: |
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| the time between the presentation of a stimulus and the completion of the movement. |
| Response time: |
| In other words: response time = reaction time + movement time |
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| Reaction time is not about movement, it is about how quick the brain processes the information. It is information processing time, the time for us to make a decision. |
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| Movement time is the time it takes to move. It is the driving off the blocks, the first part of movement to finishing the race, breasting the tape at the end. |
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| Response time is reaction time plus movement time. How quickly we respond depends on how quickly we react and how quickly we move. |
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| When is reaction time important within your chosen sport? |
| Importance of short reaction time in sport: |
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| RT is about making decisions very quickly so quick RTs gives us time for options, and avoid injuries (avoid sliding tackles in football).s. The quicker you react the less time your opponent has and the fewer options your opponent has. You can get ahead start against other competitors (eg. Sprint starting in the 100m). |
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| Reaction time is an ability; it varies between individuals. Research suggests that the following characteristics are likely to affect reaction time: |
| Factors affecting reaction time in sport: |
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| age and sex |
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| health � ill health slows reactions |
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| body temperature � the colder, the slower the reaction |
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| personality � extroverts tend to have faster reactions than introverts |
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| length of neural pathways � the further information has to travel, the slower the reaction and also the slower the response time |
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| state and alertness, arousal and / or motivation |
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| previous experience |
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| ability |
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| selective attention |
| The demands of the task and the nature of the stimulus also influence reaction time: |
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| the intensity of the stimulus |
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| the probability of the stimulus occurring |
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| the sense being used for detection � see figure below: |
| the existence of warning signals and the context to which the stimulus is expected |
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| Reaction time itself is to a large extent genetically determined but overall reponse time can be improved. You need to analyse the type of skill and the requirements of the sport and decide where in the overall response gains can be made. |
| Improving response time: |
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| Need to coach concentration and focusing |
| e.g. focusing on starter�s voice and sound of gun in sprint start and separating this from background noise and negative thoughts. |
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| Detecting relevant cues |
| In CRT situations, e.g. goalkeeper learning to analyse body language at penalties. |
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| Practice drills and reactions to certain stimuli |
| This will help develop decision making. In open skills by working on set pieces and game situations as well as plenty of practice in the game itself. |
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| Change in attentional focus |
| Ability to switch quickly from concentration on opponent to field of play in rugby |
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| Controlling anxiety |
| Anxiety slows reaction times by adding competing neural activity to the information-processing system |
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| Teach mental rehearsal |
| �psyching up� |
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| Warm-up |
| Ensure sense organs and nervous system are ready to transmit information and the muscles to act upon it. |
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| Knowledge |
| RT is influenced by the uncertainty of the stimulus to the performer, i.e. his / her lack of knowledge. More practice gives more knowledge, which in turn reduces uncertainty and hence reaction time. |
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| Reaction time can be divided into two types: |
| Simple Reaction Time and Choice Reaction Time: |
| Simple Reaction Time (SRT) and |
| Choice Reaction Time (CRT) - HICK'S LAW |
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| SRT is the time taken to start a response to a single stimulus e.g. the sprinter at the start of the race. |
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| CRT is the time taken for an individual to respond correctly from a choice of several stimuli each one demanding a different response. e.g. the basketball player at the top of the key deciding whether to shoot, pass or dribble. |
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| As the number of choices increases, so does reaction time. |
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| CRT improves with practice. Even when there is a low stimulus-response compatibility. |
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| CRT is far commoner in sport. Performers have to make a choice about what to do. |
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| SRT is quicker when attention is given to it. Experiments have shown that audible stimuli produce quicker SRT's than visual stimuli. |
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| The skilled performer has a much quicker CRT than the novice. |
| Can you explain why? |
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| Diagram to show the whole sequence of responding to a stimulus in the context of a sprint. |
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| The more choices that are available, the slower the CRT. This is Hick's Law. |
| HICK'S LAW |
| 'Choice reaction time is linearly related to the amount of information that must be processed to resolve the uncertainty about the various possible stimulus response alternatives.' |
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| PRP is linked to response time. When there is more than one stimulus to attend to, we might attend to the wrong one, make a decision, realise that a second stimulus has to be attended to and dealt with, and therefore there is a delay. |
| Pstchological Refractory Period (PRP): |
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| The theory that underpins this is called the single channel hypothesis (SCH). When information is coming into the brain, the theory states that you only have room within the single channel organ, our brain, for one piece of information at a time. And therefore, if that one piece of information is incorrect, it has to be got rid of before we can deal with the second piece of information. This is the reason for the Psychological Refractory Period. |
| You are a table tennis player, the ball is coming to your forehand, you make a decision to make a forehand. You haven�t moved yet, but you can see the ball coming towards forehand. But suddenly the ball hits the top of the net, you then have to wipe the first decision out of your head and make a second decision, a backhand. It is that delay, with attending and then wiping out the first decision, and then attending to the second decision, that is called the Psychological Refractory Period (PRP). |
| Example 1: |
| We use the PRP for our advantage in sport because we give cues because when responding to a stimulus, there is a short delay, whilst the performer decides how to respond to the stimulus, and initiates the appropriate motor programme. |
| Faking a rugby pass to someone then suddenly passing it to them. What happens? The passer has given the receiver more than one stimulus. The receiver starts to respond to the first stimulus, realises that that wasn�t the stimulus to respond to and then has to make a second decision. This affects how quick we are able to respond. |
| Example 2: |
| During the time that this takes, the performer, because of the limited capacity of the brain to deal with the processing of information, cannot produce a response to any other stimulus. If a second stimulus is given, the reaction time is much slower than normal. |
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| Anticipation is a strategy used by sportspeople to reduce the time they take to respond to a stimulus. Two types: |
| The Role of Anticipation: |
| 1) Temporal anticipation: the sprinter who attempts to anticipate when the gun will go off |
| 2) Spatial or event anticipation: the tennis player who anticipates the type of serve the opponent will use. Player learnt to detect certain cues early in serving sequence which predict the type of serve. |
| The dangers of anticipation are obvious. They will look foolish if they anticipate wrong. But the advantages of getting it right are great! |
| Coaches can help performers learn to identify certain cues so that they are more able to anticipate successfully. |
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| In competition the athlete should avoid making the same response, or presenting the same stimuli, all the time. This leads an opponent to treat the situation as SRT, and thus allows him to minimise the time taken to respond. Hence the athlete should try to give his opponents as wide a variety of stimuli as possible to increase their opponents CRT. The athlete should practice to develop as wide a range of new movements as possible, so as to increase the number of possible stimulus alternatives to present to an opponent. |
| Applications of RT for the performer: |
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| CARD GAME: SRT & CRT: |
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| Reaction Time Homework: |
| 1. What is the difference between reaction time and response time? (2 marks) 2. List two skills in which fast response times are important and two skills in which fast response times are unimportant. Justify your choice. (4 marks). 3. Why is it important to react quickly your chosen sport? (2 marks) 4. Make a list of al the factors that you feel affect your reaction time in one skill in your chosen activity. (2 marks) 5. State Hicks Law and give an example of its relevance in sport. 6. Explain the extent to which fast reaction times contribute to performance in (i) self and externally paced skills; (ii) open and closed skills 7. The time it takes for a performer to react to stimuli can effect the resultant performance. (i) If you were the receiver of a serve in tennis, give three factors which would affect your response time. (3 marks) (ii) How would you cut down the time it takes for you to respond to the server? (3 marks) (iii) Sketch a graph to illustrate the relationship between reaction time and the number of possible responses. (3 marks) 8. If the shuttle hits the top of the net during a rally in badminton, the receiver has to adjust the response. There is a delay between processing the first stimulus and the final response. (i) What is this delay called? (1 mark) (ii) Explain why this delay could occur . (2 marks) |
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| KEY TERMS: |
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| Reaction Time |
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| Movement Time |
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| Response Time |
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| Importance in sport of a short reaction time |
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| Factors affecting response time in sport |
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| Psychological Refractory Period (PRP) |
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| Single reaction time (SRT) |
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| Choice reaction time (CRT) Hick's Law |
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| Role of anticipation |