28619
OBJECTIVES : The aim of the present research was to determine if amphetamine - abstinent ecstasy users have changes in occipital lobe functioning , as revealed by two studies : a masking study that directly measured the width of orientation tuning bandwidths and a contour integration task that measured the strength of long - range connections in the visual cortex of drug users compared to controls .
 Chemical: amphetamine; Chemical: ecstasy
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: amphetamine, ecstasy 
Answer:
 Chemical: amphetamine; Chemical: ecstasy