How does the WMM explain interference in dual-task experiments?

• A. Interference occurs when two tasks compete for the same long-term memory.
• B. Interference occurs only when tasks are both verbal.
• C. Interference occurs when both tasks compete for the same WM subsystem or CE resources.
• D. Interference is unrelated to WM subsystems.

Answer: (C)

The main idea being tested is that interference in dual-task performance comes from competition for limited working memory resources—specifically, the same WM subsystem or the central executive's processing capacity. In the Working Memory Model, each subsystem handles different kinds of information: the phonological loop for verbal information, the visuospatial sketchpad for visual-spatial information, and the central executive for attention and control. When two tasks demand the same subsystem, they compete for its limited resources, so performance drops. If the tasks tap different subsystems, interference is reduced because each task has its own pool of resources. The central executive can also become overloaded when both tasks require high-level control, even if the tasks use different subsystems. So, interference arises because two tasks are drawn from the same WM resources, either the same subsystem or the same central executive capacity. This isn’t about long-term memory, and it isn’t limited to verbal tasks—two spatial tasks can interfere just as the same verbal task can.