13404
OBJECTIVES : To examine the generality of this latter effect , the present study employed a delay - discounting task to determine if acute and sub - chronic nicotine will also increase impulsive choice when subjective reward value is manipulated by changes in the probability , rather than magnitude , of reward .
 nicotine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 nicotine