Chapter 2 Processing Information and Making Decisions

Objectives This chapter will help you to understand the following: The information-processing approach for understanding motor performance The stages that occur during information processing Various factors that influence the speed of information processing (continued)

Objectives (continued) The role of anticipation in hastening the speed of responding Memory systems and their roles in motor performance

Information-Processing Approach Researchers have found it useful to think of the human being as a processor of information (like a computer). A goal of researchers interested in the performance of motor skills is to understand the specific nature of the processes in the box labeled “The human” in figure 2.1.

Figure 2.1

Stages of Information Processing There are three stages through which information must pass on the way from input to output. Stages are nonoverlapping (processing in two different stages cannot occur at the same time).

Stimulus Identification Stage The system’s problem is to decide whether a stimulus has been presented and, if so, what it is. It is primarily a sensory stage. The components of stimuli are thought to be assembled in this stage. Patterns of movement are detected.

Response Selection Stage The system’s problem is deciding what response to make, given the nature of the situation and environment. It is a transition process between sensory input and movement output.

Movement Programming Stage The system’s problem is organizing the motor system to make the desired movement. Before producing a movement, the system must ready the lower-level mechanisms in the brain stem and spinal cord for action and retrieve and organize a motor program.

Figure 2.2

Reaction Time (RT) It is an important performance measure indicating the speed and effectiveness of decision making. RT interval is a measure of the accumulated durations of the three stages of processing. Any factor that increases the duration of one or more of these stages will lengthen RT.

Figure 2.4

Number of Stimulus–Response Alternatives It is a factor that influences RT. RT is the time required to detect and recognize the stimulus and select and initiate the proper response. As the number of possible S-R alternatives increases, there is an increase in the time required to respond to any one of them. See Hick’s Law.

Stimulus–Response Compatibility It is the extent to which the stimulus and the response it evokes are connected in a natural way. For a given number of S-R alternatives, increasing S-R compatibility decreases choice RT. Practice can help overcome low S-R compatibility.

Population Stereotypes It is a type of stimulus–response compatibility. The association of the stimulus and response is likely learned in population stereotypes (e.g., red for stop, green for go). We sometimes act habitually due to specific cultural learning.

Anticipation It is one way in which learners cope with long RT delays. A performer can organize movements in advance. Event, spatial, and temporal anticipation. Experts have a large advantage over novices in perceptual anticipation.

Benefits of Anticipation A correct anticipation can result in the processing lag equivalent to RT = 0 ms. It can start an action simultaneously with a signal or even before it. One factor that affects the capability to predict effectively is the regularity of events.

Costs of Anticipation The primary disadvantage occurs when the anticipated action is not what actually happens. An incorrect anticipation will require more processing activities and longer delay compared to a response to a neutral or unanticipated event. It can create a biomechanical disadvantage.

Short-Term Sensory Store It is responsible for storing vast amounts of sensory information only long enough for some of it to be abstracted and further processed.

Short-Term Memory It is a temporary holding place for information (e.g., a phone number given to you verbally). Unless we repeat the item, we know that this phone number will be lost from memory in a short time. Rehearsal is the process by which we keep from losing information from STM.

Long-Term Memory It contains very well-learned information that has been collected over a lifetime. A vast amount of information can be stored in LTM by processing in STM (requires effort). To say that someone has learned something means that information was processed in some way from STM to LTM.