THE BARRIER CHOICE PARADIGM: ASSESSING HALOPERIDOL WITH EIGHT RESPONSE ALTERNATIVES AND TWO TRAVEL

Research has shown that the same doses of a dopamine antagonist that cause de suppression of leverpressing for a preferred meal, facilitate the consumption of another non-preferred meal freely available inthe choice situation. This finding suggests that dopamine antagonists change the organism’s preferencesin favor of alternatives that require less physical effort. These ideas were assessed in a choice situation thatincluded eight sources of food simultaneously available, and two travel requirements, one being harderthan the other. After rats responded in such situations for 30 consecutive days, four doses of haloperidol(0.04, 0.08, 0.16, & 0.24 mg/kg) were assessed (ip) over a 12-day period. None of the doses suppressedlever pressing for food, but they changed allocation of responses. At low doses (0.04 & 0.08) of haloperidolundermatching was observed, the slopes of the generalized matching low being below 1.0. High doses(0.16 & 0.24), however, produced results consistent with overmatching, the slopes were above 1.0. Thesefindings support the idea that in choice situations dopamine antagonists affect choices and preferences.