In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: A conjunction analysis of the encode and recall phases of the task revealed ecstasy - specific hyperactivity in bilateral frontal regions , left temporal , right parietal , bilateral temporal , and bilateral occipital brain regions .
### Output Text:
A conjunction analysis of the encode and recall phases of the task revealed <span class="chemical">ecstasy</span> - specific hyperactivity in bilateral frontal regions , left temporal , right parietal , bilateral temporal , and bilateral occipital brain regions . 