Psychochemical agents are primarily designed to affect the central nervous system, leading to alterations in mental states, perception, and behavior. The correct answer focuses on their impact of producing mental confusion and dysfunction, which aligns with how these agents operate. They can cause disorientation, impaired judgment, and various cognitive impairments, hindering a person's ability to think clearly or respond appropriately.
This effect is often leveraged in various contexts, such as military operations or psychological warfare, where disrupting the enemy's mental capacity can be strategically advantageous. The other effects listed do not accurately represent the primary purpose or effect of psychochemical agents; for example, while physical incapacitation may occur with some agents, it is not their primary function. Similarly, enhancing cognitive abilities and inducing sleep are not characteristics associated with the use of psychochemical agents.