Final answer:
Carol's ability to read books while holding them upside down demonstrates perceptual adaptation, which is the visual cortex's ability to adjust to changes in the visual field, as seen in experiments with inverted vision.
Step-by-step explanation:
After practicing, Carol was able to read books while holding them upside down. This best illustrates perceptual adaptation. Perceptual adaptation is a visual ability that allows us to get used to changes in our visual field such as inverted vision. This was evidenced in experiments from the 1960s where subjects wore prism glasses that inverted their vision. Initially, subjects had difficulty interacting with their environment, but over time, they adapted and behaved naturally despite the visual distortion. This ability shows the flexibility of the visual cortex and demonstrates how the brain can adjust to new visual information, which is not to be confused with retinal disparity, which involves depth perception due to differences in images on each retina, or perceptual constancy, which allows us to perceive objects consistently despite changes in viewing conditions.