Response acquisition under signaled delay of reinforcement in temporally defined schedules [Adquisici�n del responder bajo condiciones de reforzamiento demorado en programas temporales se�alados]

A temporally defined schedule of delayed reinforcement was used to esta-blish lever pressing by rats. A constant 8 s Td subinterval was introduced at different temporal locations into reinforcement cycle (64 s). The first response during Td produced reinforcement at the end of the cycle. Varying the temporal location of Td generated reinforcement delays of either 8 s, 24 s or 56 s. Three rats each were assigned to different delay duration. Response rates were considerably lower when Td was at the beginning of the cycle (56 s) than when the opportunity to respond was at the middle (24 s) and its end (8 s). The results are discussed focusing in the response rates and the convenience of responses per reinforcement proportion as an effectiveness acquisition measure