Efficiency of information processing to include:: Single channel hypothesis.

The idea

The single channel hypothesis states that a performer can process only one piece of information at a time, so a second stimulus must wait until the first has been processed. In AQA A-Level Physical Education, this hypothesis is used to explain the psychological refractory period and the limits of decision making in fast sports. For example, a cricket batsman facing a disguised slower ball may begin a shot, then have to adjust to a different delivery; the adjustment is delayed because the first decision is still occupying the channel. The hypothesis does not mean that performers cannot attend to several things, but that central decision making is serial. Efficient performers reduce the delay through anticipation, cue detection and practised decision making, which shortens processing time and frees the channel sooner.

What earns the marks

• States that the single channel hypothesis proposes that only one piece of information can be processed at a time.
• Explains that a second stimulus must wait until the first has been processed.
• Links the hypothesis to the psychological refractory period and delayed responses.
• Applies the hypothesis to a sporting example where a performer must adjust to a second stimulus.
• Recognises that anticipation and practice can reduce, but not remove, the processing delay.

Common mistakes and how to put them right

• Thinking the single channel hypothesis means a performer cannot see or hear a second stimulus.

  Put it right: The stimulus may be detected, but central processing of it is delayed.

• Confusing the hypothesis with the psychological refractory period.

  Put it right: The hypothesis is the explanation, while the psychological refractory period is the observable delay.

• Assuming skilled performers have unlimited parallel processing.

  Put it right: Skilled performers process more efficiently and anticipate better, but the single-channel limitation still applies.

• Believing that the hypothesis applies only to beginners.

  Put it right: It describes a general limitation of information processing for all performers.

Exam tips

• State the hypothesis clearly: one piece of information is processed at a time.
• Use the term 'serial processing' to show understanding of the mechanism.
• Link the hypothesis directly to the psychological refractory period in your explanation.
• Support your answer with a sporting example that shows a delayed response to a second stimulus.