What type of study involves the enrollment of undergraduate students to assess mood effects on problem-solving behaviors?

A cognitive psychology study is focused on understanding how mental processes influence behaviors, including those related to mood and problem-solving. By enrolling undergraduate students to assess how their mood affects their ability to solve problems, this type of study is effectively examining the cognitive aspects of how mood states can impact reasoning, decision-making, and other related cognitive functions. Cognitive psychology encompasses a broad range of topics, and the scenario described is closely aligned with exploring the cognitive mechanisms by which mood can alter problem-solving capabilities.

Other types of studies have distinct characteristics that don't directly align with the focus on mood and cognitive processes. Longitudinal studies track changes over time, qualitative research centers on understanding phenomena through non-numeric data, and observational studies involve watching subjects without intervention. In contrast, the essence of the proposed study centers on the relationship between specific cognitive functions and mood, which is why it fits well within the framework of cognitive psychology.