A sufficient condition for conditional expectation to be monotonically related to distribution parameters

In this paper we give a sufficient condition for conditional expectation to be a monotonic function of a parameter of the joint probability distribution. A second sufficient condition is given for the case where varying the parameter of the joint distribution leaves the shape of that distribution unchanged. Finally, an application of the condition is illustrated on the counter models for choice reaction time of LaBerge (1962) and Nickerson (1969).     

Automated preference testing apparatus for rating palatability of foods

An electronic preference testing apparatus is described for measuring taste preference of rodents and other small animals with solid or liquid foods. The apparatus is designed on the principle of the two-choice, preference technique. It operates photoelectrically with a sequence of presentations so that whenever a subject eats from a compartmentalized food tray, a standard and a test food are each briefly sampled alone before both foods are presented together (in alternate positions) for preference determination. Preferences are automatically recorded on digital counters. The apparatus is built in two modules (a preference tester and the master control) connected by multiconductor cable. The modular design provides portability and isolation of the animals from the major noise-producing components. Diagrams of the apparatus are given, and test results from a trial that evaluated positional bias and a sucrose-concentration preference experiment are presented to demonstrate its application in research.     

The effects of instructions,fixed rate of presentation,and complexity on free looking time

The effect of stimulus complexity, prior experience with a short or long fixed rate of presentation (FRP) and S’s knowledge concerning the purpose ot the experiment on free looking time (FLT), was examined. Results indicated that under all conditions, Ss view complex stimuli longer than simple. A long FRP produced longer FLT than did a short FRP for Ss uninformed of the purpose of the experiment, hut FRP had no effect on FLT for Ss who were informed.     

Feedback in behavior modification: an experimental analysis in two phobic cases

Two illustrations of single-case research are described in which an isolated therapeutic variable was sequentially introduced, withdrawn, and reintroduced while changes in a clinically relevant behavior were measured. A claustrophobic patient and a knife-phobic patient received graduated practice in facing their phobic stimuli; length of time the claustrophobic patient stayed in a small dark room per trial, and length of time the knife-phobic patient kept knife exposed per trial were measured. In both experiments, when feedback of these time scores was withdrawn, ongoing progress was retarded. Reinstatement of feedback led to renewed improvement. In Experiment 2, adding and removing contingent verbal praise against a constant background of precise feedback did not significantly alter rate of progress.     

Presentation modality,rehearsal-prevention conditions,and auditory confusions in tests of short-term memory

Ss were presented four-letter sequences either auditorily or visually and asked for ordered recall after 0, 2.1, 4.2, 8.4, or 12.6 sec of digit categorization. Three different rehearsal-prevention conditions were required during presentation of the memory set: categorizing, suppressing (saying "dah"), or pronouncing each letter. Recall was worst after categorizing, best after pronouncing. Auditory presentation led to better recall after no delay but more rapid forgetting than visual presentation, regardless of the rehearsal-prevention condition. These results, and analyses of auditory confusions, are inconsistent with a view of memory which asserts that sensory information is encoded auditorily regardless of presentation modality or vocalization behavior during presentation.