Changeover delay and concurrent schedules: some effects on relative performance measures

The pigeon and the rat partition total response output between both schedules of a concurrent variable-interval pair. The quantitative nature of a partition seems critically dependent on the relative rates with which the two schedules provide reinforcements for responding, in addition to the changeover delay. The manner in which the changeover delay controls the partition was studied by varying the duration of the changeover delay from 0 to 20 sec with each of two pairs of concurrent variable-interval schedules, viz., Conc VI 1.5-min VI 1.5-min and Conc VI 1-min VI 3-min. Rats served as the subjects and brain stimulation was employed as the reinforcer. When the schedules were Conc VI 1.5-min VI 1.5-min, relative response rate approximated 0.50 at all values of the changeover delay. When the schedules were Conc VI 1-min VI 3-min, relative response rate, computed with respect to the VI 1-min schedule, increased when the duration of the changeover delay increased. Changeover rate decreased when the duration of the changeover delay increased. The decrease was the same for both VI schedules of the Conc VI 1.5-min VI 1.5-min pair but was more rapid for the VI 3-min schedule of the Conc VI 1-min VI 3-min pair.     

Book reviews

The Journal of Value Inquiry -     

Intake and Walk-in Procedures in a College Counseling Setting

Modifications of the intake procedure usually employed in counseling settings were adopted in order to provide students the opportunity for immediate contact with a counselor. Elimination of the waiting list, reduction in number of missed appointments, and reduction of length of counseling came about. Staff satisfaction with the new approach has been high and there would be opposition to reverting to the scheduled initial interview. Possible changes in the type of problem or clients' readiness for problem-solving were observed.     

Cation and anion contributions to gustatory quality of simple salts

Curves of mean percentages of the four gustatory quality responses as a function of concentration of solutions of LiCl, KCl, lithium sulfate, and potassium sulfate were evaluated as to the relative contributions of the cation and anion to the quality. It was concluded that chloride ion, and sulfate ion to a lesser degree, were responsible for the salty quality. In the mid-range concentrations, potassium ion was responsible for the bitter quality, and lithium ion, by means of an ion-soliient interaction; was responsible for the sour quality reported. At the very low concentrations, at which all salts tested evoked sweet responses, a structure produced by a solvent-cation interaction was assumed to be responsible. The details of the presumed structure are still to be clarified. Although one ion in each salt is primarily responsible for a particular quality over a given concentration, the other ion usually modifies the effect.