Probability learning as a function of momentary reinforcement probability

Pigeons were trained on a probability learning task where the overall reinforcement probability was 0.50 for each response alternative but where the momentary reinforcement probability differed and depended upon the outcome of the preceding trial. In all cases, the maximum reinforcement occurred with a “win-stay, lose-shift” response pattern. When both position and color were relevant cues, the optimal response pattern was learned when the reinforcement probability for repeating the just-reinforced response was 0.80 but not when the probability was 0.65. When only color was relevant, learning occurred much more slowly, and only for subjects trained on large fixed ratio requirements.     

Abortion outcome as a function of sex-role identification

The present study investigated the relationship between sex-role identification and abortion outcome in 120 women receiving first trimester abortions. The sex-role concept dimension was measured both by self-attributions of sex-role traits (as measured by the Bern Sex-Role Inventory) and by life-style (career vs. homemaker) trait attributions. Psychological and physiological aspects of abortion outcome were included; slightly more than 7% of scores were in the symptomatic range, similar to percentages found in previous studies. Both Androgyny (r = -.42, p <.001) and Masculinity (r = -.23, p <.05) were found to be related to positive abortion outcome. Androgyny was more strongly related, which suggests that a balance of masculine and feminine traits, at least for women in the post-abortion situation, is preferable to high Masculinity scores alone. Congruence between one's self-image and one's image of a career woman was also found to be related to abortion outcome (r =.31, p <.01). In attempting to differentiate between the upper and lower 10% of the distribution of abortion outcome, only two variables, Androgyny and self-career congruence, survived parameter criterion, and accounted for 32% of the variance.     

Temporal duration as a function of information processing

Estimation of duration has been shown to be a function of the amount and manner of organization of information processed during an interval. It was assumed that the use of an organizational schema to encode information reduces the actual amount of information stored. It was predicted that the use of an organizational schema will result in relatively shorter estimates of duration. Eighteen undergraduate subjects made estimates of intervals (.58 to 3.0 sec.) during which they watched film animations of moving geometric forms. In a second condition the same subjects were instructed to organize the animation as representing social interaction. An interaction showed that the use of an organizational schema to encode information resulted in smaller estimates for the longer intervals.