 One exception to the trend of explaining away putative cases of cognitive penetration in terms of perceptual learning is Cecchi (2014). Cecchi argues that a particular case of perceptual learning—that found in Schwartz, Maquet, and Frith (2002)—should count as a case of cognitive penetration. The study in question found changes in the primary visual cortex due to learning, and also that these changes were brought about by higher areas in the brain influencing the primary visual cortex. Because the perceptual changes were the result of top-down influence, Cecchi argues that this case of perceptual learning should count as a case of cognitive penetration.