2015
SCOB testing of food - restricted animals , using a multiple fixed ratio ( FR ) / fixed interval ( FI ) schedule ( FR20 : FI120 ) , was conducted prior to each exposure to maintain the operant behavior ; the data from Weeks - 1 , 4 , 8 , and 13 were evaluated for evidence of neurotoxicity .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 None