Effects of methylphenidate on learning a 'beginning reading vocabulary' by normal adults.

The effects of methylphenidate on reading was studied by having nine adults learn a beginning vocabulary of 96 Chinese characters under placebo and 5 mg and 10 mg methylphenidate by two teaching methods which differed in the rate at which new items were introduced for practice. Using lists composed of 12 characters and their English equivalents, all items were presented prior to the start of practice trials (simultaneous method), or each item was introduced only as the subject practiced items previously presented (progressive method). Learning performance was analyzed in terms of total errors and errors made at two criterion stages in list acquisition. Overall performance was significantly facilitated by the low (5 mg) dose or methylphenidate, but only with the simultaneous method. Significant drug effects were also obtained at criterion stages which were associated with high error rates. It was concluded that drug effects are likely to be most pronounced in difficult learning situations and that dosage appears to be an important variable for consideration in further studies.