Which of the following describes cognitive capacity?

• A. Cognitive capacity is the total amount of information that can be held in long-term memory.
• B. Cognitive capacity measures physical brain size.
• C. Cognitive capacity is the speed at which we can perform tasks.
• D. Cognitive capacity refers to our ability to perform cognitive processes.

Answer: (D)

Cognitive capacity is about how much mental work we can handle and the extent to which we can carry out cognitive processes. It reflects the system’s ability to plan, reason, solve problems, and manipulate information within our attentional and working-memory resources.

This best fits because it’s not about how much information is stored in long-term memory (that storage is vast and not a simple finite “capacity”), nor about the physical size of the brain, nor about how fast we perform tasks. Capacity is about the potential to perform cognitive operations given limited resources, such as how many items you can hold and manipulate at once in working memory.