I think you're onto the main question. Were the fish neglecting more natural instincts and past learned behaviours that led to the search for food -- instead pr

I think you're onto the main question. Were the fish neglecting more natural instincts and past learned behaviours that led to the search for food -- instead preferring the platform that indicated a release of the drug? It would need to show that they were acting actively against their best survival interests for an endorphin release provided by a substance they learned they could acquire by acting in this certain way. That would be the damning conclusion.