20579
METHODS : Experiment 1 examined the effects of nicotine and methylphenidate on delayed matching - to - sample ( DMTS ) and self - ordered spatial search ( SOSS ) performances in rhesus monkeys ( DMTS : n = 7 ; SOSS : n = 6 ) to determine the validity and reliability of best dose effects .
 Chemical: nicotine; Chemical: methylphenidate
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: nicotine; Chemical: methylphenidate