Consonant and vowel discrimination ability was unimpaired in Mecp2 mutant rats. (a) Mecp2 and control rats were trained to perform a consonant discrimination task, where they pressed a lever in response to the speech sound ‘dad’, and refrained from lever pressing to the speech sounds ‘bad’, ‘gad’, ‘sad’, and ‘tad’. Error bars indicate SEM across rats. The dashed line indicates chance performance (50%). (b) Mecp2 and control rats were trained to perform a vowel discrimination task, where they pressed a lever in response to the speech sound ‘dad’, and refrained from lever pressing to the speech sounds ‘deed’, ‘dood’, and ‘dud’.