In a study on the biological bases of learning, lab rat A is given a drug that blocks dopamine activity in its brain. Thereafter, the rat is placed in an operant chamber where a lever-pressing task is shaped through positive reinforcement.
We should expect that the rat will have .

We should expect that the rat will have more difficulty learning the task than a regular rat.

Explanation:

Dopamine plays various roles on the brain, such as enhancing the executive functions, playing a role on motivation, pleasure and gratification. It is the reward system, meaning that it plays a big role in getting an individual to do something because of the reward he/she gets from it, thus motivating the individual.

In this case, we can conclude that the rat with the blocked dopamine activity will have more difficulty learning the lever-pressing task because it loses its reward system and its motivation to do so.

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abraham lincoln issued the preliminary emancipation proclamation on september 22nd, 1862. it stipulated that if the southern states did not cease their rebellion by january 1st, 1863, then proclamation would go into effect.