In the human study, when the number of responses required for each injection was progressively increased over consecutive sessions, high rates of responding were maintained by nicotine injections, but not by concurrently available saline injections, at response requirements as high as 1600 responses per injection.
During the final FI15 FR10 S) schedule, responding was maintained by contingent presentation of the cocaine-associated CS after 10 responses (FR10 S); cocaine was delivered on completion of the first 10 lever presses after the expiration of each 15-min fixed interval.
Response rate declined rapidly from an initially high level at the start of the trial, and a relatively constant rate of responding was maintained throughout the remainder of the trial.
At 12 weeks, responding patients were maintained on bexarotene 300 mg m−2 p.o. daily until disease progression or the treatment was no longer tolerated.
Thus if the original CS is substituted by a transfer CS, responding will be maintained to the extent that the test compound is similar to the training compound – so that an occasion setter should be equally effective with a transfer CS, regardless of whether its outcome matches that of the occasion-setting discrimination or not.
Therefore, although a lack of RIP140 leads to an alteration in the metabolic function of skeletal muscle the ability of RIP140 null mice to respond to a dietary challenge is maintained.
This means that this body of theory could be brought to bear to help understand how social variation in reproductive behaviour is maintained, how it respond to changes in the environmental context, and how and over what timescale interventions should be evaluated.
However we must first understand how the CMV footprint is maintained in HIV patients responding to ART.
During development, a fetus and its placenta must respond to a changing maternal environment to ensure normal growth is achieved and survival is maintained.
The finding that self-administration responding continued to be maintained at high rates during the first exposure to saline substitution conditions (Fig. 2) suggests that habitual behavior had progressively developed in the monkeys and that they were becoming insensitive to the outcome of their actions.
