Magoon, M.A. & Critchfield, T.S. (2008).
Concurrent schedules of positive and negative reinforcement: differential-impact and differential-outcomes hypotheses.
Journal of the Experimental Analysis of Behavior, 90, 1-22.
Considerable evidence from outside of operant psychology suggests that
aversive events exert greater influence over behavior than equal-sized
positive-reinforcement events. Operant theory is largely moot on this
point, and most operant research is uninformative because of a scaling
problem that prevents aversive events and those based on positive
reinforcement from being directly compared. In the present investigation,
humans’ mouse-click responses were maintained on similarly structured,
concurrent schedules of positive (money gain) and
negative (avoidance of money loss) reinforcement. Because
gains and losses were of equal magnitude, according to the analytical
conventions of the generalized matching law, bias (log b 0)
would indicate differential impact by one type of consequence; however,
no systematic bias was observed. Further research is needed to reconcile
this outcome with apparently robust findings in other literatures of
superior behavior control by aversive events. In an incidental finding,
the linear function relating log behavior ratio and log reinforcement
ratio was steeper for concurrent negative and positive reinforcement than
for control conditions involving concurrent positive reinforcement. This
may represent the first empirical confirmation of a free-operant
differential-outcomes effect predicted by contingency-discriminability
theories of choice.
Key words: positive reinforcement, negative reinforcement,
concurrent schedules, differential-outcomes effect, generalized matching
law, humans, mouse click, money