Temporal control by signals of interval duration within variable-interval schedules

Rats' lever pressing produced sucrose reinforcers on a variable-interval schedule where, in different conditions, the duration of a stimulus presented immediately after reinforcement was either correlated or uncorrelated with the duration of the current interreinforcement interval. Under the baseline schedule, in which no stimulus was presented, the minimum interreinforcement interval was 8 s and the mean postreinforcement pause of each subject approximated this value. Response rates increased slowly over the first 10 to 15 s and then remained roughly constant throughout the remainder of the interval. In both the correlated and uncorrelated conditions, the added stimulus resulted in the postreinforcement pauses lengthening to values in excess of the duration of the preceding stimulus. This resulted in a poststimulus pause which was, in most cases, roughly constant irrespective of the duration of the preceding stimulus, or of the reinforcement contingencies prevailing immediately after stimulus offset. Local response-rate patterns in the uncorrelated conditions were similar to those obtained under the baseline schedule in which no stimulus was presented. However, in the correlated condition local response rates increased across the remainder of the interreinforcer interval. Further, the rate of acceleration was inversely related to the duration of the preceding stimulus. These results show that a correlation between stimulus duration and the ensuing time to reinforcement can control behavior—a type of temporal control not previously reported.     

The effects of ethanol intoxication on phobic anxiety

Behavioral conceptions of alcohol abuse often include the hypothesis that drinking behavior is a negatively reinforced operant, with ethanol intoxication viewed as alleviating aversive environmental and internal states. This hypothesis has not been confirmed or refuted by previous studies which employed mild stressors and limited assessment methodology. In the present experiment, 22 patients with severe phobias approached their phobic animal under two consecutive conditions—first while sober and second after drinking either a placebo or an intoxicating dose of ethanol. The severe anxiety induced was assessed behaviorally, physiologically and by the patient's self-report of fear. The intoxicated patients did not experience decreased anxiety, tachycardia or avoidance, compared to the placebo group. These results have clinical implications and suggest the need to reconsider tension-reduction theories of alcohol abuse.     

Generalization of treatment effects in training public speakers

Three studies compared the efficacy of various treatments for public-speaking incompetence. These effects were evaluated for the target behavior as well as for generalization effects across situations (conversations), settings (different sizes and types of audiences) and time (6-month follow-up). The first study showed that Self-instructional Training, either alone or in combination with other procedures, produced little or no benefits. The second study demonstrated the superiority of a Skills Training program over flooding therapy, while the final study failed to detect any enhancement of treatment benefits for the addition of home-practice to the Skills Training. In the first two studies generalization occurred across the three dimensions (settings, situations and time), while in the final study it was shown that the program was effective for a clinical population as well as recruited volunteers.     

Two stages in postcategorical filtering and selection

Memory &; Cognition - In a modified Stroop paradigm, Kahneman and Henik (1981) varied the spatial location of incompatible color words in relation to the position of the ink color to be named. A...