Maya spent a sleepless night cramming for an exam. When Maya took her exam the next day, she noticed that it took her longer than usual to process information on the exam. Maya had to re-read questions several times and had trouble deciding on the correct answer for many questions. A sleep researcher would likely say Maya is experiencing _____ due to sleep deprivation.

a. cognitive slowing
b. cognitive rigidity
c. decreased motivation
d. cognitive impairment