John W. Hennessy’s research while affiliated with University of Illinois at Chicago and other places

Conducted a series of experiments to demonstrate that organisms tend not to repeat a response after reinforcement is "consumed," contrary to the basic tenet of learning theory. Using varied combinations of Ss, including college sophomores, nurses, children, and "real people," and varying apparatus from a black box to paper cups, the hypothesis was confirmed. Additional hypotheses were developed relating to naivete, expectancies of deception, and elaborate instrumentation. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Ran 60 male Sprague-Dawley albino rats in a shuttle box with 3 levels of shock intensity-high (H), medium (M), and low (L)-which varied independently on each side. This yielded 6 groups defined by the shock level in the 2 chambers: H-H, M-M, L-L, H-L, H-M, M-L. Results indicate that when active shock level was held constant, avoidance behavior was a function of passive shock level, with lower passive shock level producing higher levels of avoidance. Avoidance was not a function of active shock level when passive shock level was held constant. 10 controls were run using a unidirectional paradigm, and avoidance was not found to be a function of the active shock level. Results are interpreted as emphasizing the role of passive avoidance in bidirectional shuttling. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Sprague-Dawley rats received daily injections of either ACTH, hydrocortisone, corticosterone, or placebo throughout the acquisition and extinction of a food-reinforced runway response. The results showed that hormone injections produced no systematic effects upon acquisition performance. Injections of either hydrocortisone or corticosterone, however, produced faster running on early extinction trials as compared to either ACTH or placebo injection. There was some suggestion that increased corticosteroid levels, rather than some change in ACTH levels, produced the effects upon extinction responding.

Two experiments were performed which investigated the roles of goal box experience and sucrose novelty on sucrose-incentive-shift performance.It was hypothesized that both post-reinforcement delay and early sucrose experience would lead to rapid response decrements following an incentive reduction. Neither of these hypotheses were supported and further research is needed to elucidate the mechanism involved in the slow behavioral adjustments to decreased sucrose rewards. © 1973, The Japanese Psychological Association. All rights reserved.