hard · MCAT psych-soc

A researcher trains a rat to press a lever for food pellets on a schedule in which the first press after a variable, unpredictable amount of time (averaging 60 seconds) is rewarded. After training, the reward schedule is discontinued entirely (extinction begins). Compared to a second rat previously trained on a fixed-ratio 5 schedule (reward after exactly every 5th press), the first rat's lever-pressing behavior during extinction is best described as:

1. More resistant to extinction, because the variable-interval schedule made reward delivery unpredictable and decoupled from a fixed count of responses.
2. Less resistant to extinction, since interval schedules produce weaker associative strength than ratio schedules regardless of reward predictability.
3. Equally resistant to extinction, since both schedules are examples of partial reinforcement and the partial-reinforcement effect is schedule-independent.
4. More resistant to extinction, but only because variable-interval schedules generate a lower overall response rate than fixed-ratio schedules.

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