Reading focus
Syllabus: How Do We Direct Attention and Control Thought?
Distinguish perceptual demands from demands on maintaining priorities. Use the opposing predictions to ask what a difficulty manipulation actually changes.
A question to consider. Would searching among similar letters and remembering a longer digit sequence necessarily have the same effect on distraction? Specify the measurements needed to compare them.
Why this reading
Why can making a task harder sometimes reduce distraction and sometimes increase it? Lavie's proposal distinguishes demands on perception from demands on maintaining priorities, turning an apparent contradiction into contrasting predictions.
Before you read
Perceptual load concerns the processing demands of relevant stimuli. Cognitive control load concerns demands on processes that maintain task priorities, often manipulated with a concurrent memory task. Distractor interference is commonly measured by comparing responses when an irrelevant item favors the correct versus a competing response. These are operational measures, not direct readings of a single mental fuel supply.
Read for
- Compare the perceptual-load and working-memory-load manipulations in Figure 1 and explain their opposing predicted effects.
- Distinguish behavioral interference, neural responses, and explicit recognition as measures of distractor processing.
- Track exceptions involving faces, spatial overlap, sensory modality, and age rather than treating one prediction as universal.
Consider afterwards
- A harder visual search produces less distractor interference. What change besides capacity exhaustion could explain this, and how could you vary task demands while holding the display constant?
Editorial context
This compact statement of load theory offers a productive model, not a settled rule that being busy prevents distraction. Murphy, Groeger, and Greene's later review examines problems defining load, competition from additional display items, and differences among memory demands. Reduced interference alone does not prove that an unattended item received no processing.