Lie, C. & Alsop, B. (2009).
Effects of point-loss punishers on human signal-detection performance.
Journal of the Experimental Analysis of Behavior, 92, 17-39.
Three experiments using human participants varied the distribution of point-gain
reinforcers or point-loss punishers in two-alternative signal-detection
procedures. Experiment 1 varied the distribution of point-gain reinforcers for
correct responses (Group A) and point-loss punishers for
errors (Group B) across conditions. Response bias varied
systematically as a function of the relative reinforcer or punisher
frequencies. Experiment 2 arranged two conditions - one where an
unequal ratio of reinforcement (5 : 1 or 1 : 5) was
presented without punishment (R-only), and another where
the same reinforcer ratio was presented with an equal distribution of
point-loss punishers (R+P). Response bias was significantly
greater in the R-only condition than the R+P condition,
supporting a subtractive model of punishment. Experiment 3 varied
the distribution of point-gain reinforcers for correct
responses across four unequal reinforcer ratios (5 :
1, 2 : 1, 1 : 2, 1 : 5) both
without (R-only) and with (R+P) an equal
distribution of point-loss punishers for errors. Response
bias varied systematically with changes in relative reinforcer
frequency for both R-only and R+P conditions, with
5 out of 8 participants showing increases in sensitivity
estimates from R-only to R+P conditions. Overall,
the results indicated that punishers have similar but
opposite effects to reinforcers in detection procedures
and that combined reinforcer and punisher effects might
be better modeled by a subtractive punishment model than
an additive punishment model, consistent with research
using concurrent-schedule choice procedures.
Key words: behavioral evolution, biological evolution, behaviorism,
Darwin, group selection, molar behaviorism, pragmatism, social evolution