The section will look at various information processing models from the basic model to Whitings model. Also covered are Hicks Law, factors effecting Reaction time, Single Channel Hypothesis and Psychological Refractory Period.
When we are performing a skill, many decisions must be made. For example, if making an overhead clear in badminton, we must decide, where to aim the shot, how hard to hit it, where to position ourselves afterwards etc etc. The diagram below shows the process involved in making such decisions. This is closely related to the Open Loop Theory as all information is received in one block and feedback does not influence the action.
The 3 stages above can also be named Stimulus Identification, Response Selection and Response Programming. An extended, more detailed example of this is shown below.
Whiting's Model of Information Processing
This model has 3 main stages.
Perceptual Mechanisms - Information is brought in from the environment and analysed
Translatory Mechanisms - Uses this information to make a decision on the skill to be performed
Effector Mechanisms - Selected movement is sent to the muscles via the motor nerve. Importantly, no movement occurs until the effector stage.
After a decision has been made, the body performs the skilled movement using the effectors.
Response (or reaction) time, is a persons ability to take in and process information to make a decision and then put this into action. Response time = Reaction Time (The time between the onset of a stimulus and the initiation of a response.)+ Movement Time (The time it takes to complete a movement.)
Response time is affected by the following:
The time to make a decision increases, with the more choices which are available, as shown in the graph below:
Reaction time speeds up as we develop through childhood, into adulthood, to an optimal point where it then deteriorates again
Presentation of Stimuli in Rapid Succession
This is also sometimes referred to as the psychological refractory period. It is a delay in response to a second stimuli which comes in close succession to the last. For example, when playing hockey, a dummy or fake movement works to put the defender off as they initiate a response to this dummy which they must then stop and correct with a response for the attackers actual movement.
Males tend to have a faster response time than females, although this deteriorates more rapidly in old age.
If the stimulus is expected then the reaction is quicker than if it is unexpected. For example, a goalkeepers reaction to a penalty will be faster than their reaction to an unexpected shot from outside the box.
The ability to use past experiences to select the correct reaction speeds up the response time
The stronger the stimulus is, the faster the reaction will be. This is because it is easier to focus the selective attention on strong stimuli. With weaker stimuli, more irrelevant information is taken in.
If an event is anticipated then often the movements required for the reaction are prepared and began before the stimulus occurs. This is known as spatial anticipation. The best example of this is a false start by a sprinter - they were anticipating the gun and the motor programme began too early!
Single Channel Hypothesis
The Single Channel Hypothesis states that once a stimulus has been recognised and is in the process of being dealt with any secondary stimuli must wait until the first has been dealt with before it can be processed. We can only process one piece of information at a time. With more stimuli, the decision making process slows down. From an attackers point of view, the more stimuli you can present to an attacker, the easier it should be to beat them. Try to present the 2nd stimuli as close to the first as possible for maximum effect.
Psychological Refractory Period (PRP)
The PRP works alongside the single channel hypothesis. The PRP is the lull in time between finishing processing stimuli 1, before processing and making a decision on stimuli 2. An example of this is a tennis player waiting at the base line for a return shot. They see that the ball is arriving on their forehand side and they start to decide upon the appropriate response (S1). Whilst the ball is still in flight, it clips the net (S2). The time taken to forget about the first stimuli and then process and respond to S2 is the PRP