Which of the following is NOT an effect of hypocapnia?

Hypocapnia, which is a lower-than-normal level of carbon dioxide (CO2) in the blood, can lead to several physiological effects. One of these is vasoconstriction, which reduces blood flow to the brain and can lead to a decreased level of consciousness, confusion, and difficulty concentrating. This stands in contrast to the notion of "improved mental clarity."

While it might seem appealing that a reduction in carbon dioxide would enhance mental function, the reality is that hypocapnia typically results in mental symptoms such as dizziness, confusion, or even fainting due to the reduced availability of CO2 for regulating blood flow and oxygen delivery to the brain. Improved mental clarity is therefore not an effect of hypocapnia; instead, its effects often lead to diminished cognitive performance.

The other choices, such as increased depth of breathing and muscle spasms, are indeed recognized effects of hypocapnia. Increased depth of breathing occurs as a compensatory mechanism for reduced carbon dioxide levels. Muscle spasms can arise due to shifts in blood pH and electrolyte imbalances that occur with hypocapnia. Lastly, rapid fatigue may follow as the body struggles to compensate for low CO2 levels, leading to associated symptoms of weakness. This makes "im