In Luria's functional model, which of the following is one of the three basic functions?

• A. Regulate arousal (brain stem).
• B. Planning.
• C. Language comprehension.
• D. Memory consolidation.

Answer: (A)

Luria’s model splits brain function into three fundamental regulatory systems. The first system handles arousal and tone—essentially waking and readiness to act—anchored in the brainstem and related subcortical networks. This basic regulatory function provides the essential state that allows any further mental activity to occur. The second system is about planning and regulating actions—organizing and sequencing goal-directed behavior. The third system handles higher-level content like memory and language, coordinating complex cognitive processes.

So describing arousal regulation in the brainstem fits squarely with the first basic function in Luria’s scheme. It’s the foundational level that must be in place for planning or language-based processes to operate. The other options refer to higher-level processes (planning as a different basic system, language comprehension and memory consolidation as specific cognitive operations that depend on the broader systems), rather than the foundational arousal function.