Luminal distension as a possible consequence of experimental intestinal perfusion

In an experimental jejunal perfusion study, distress in healthy subjects occurred during eight out of 16 perfusions in which intestinal secretion was provoked. Calculation demonstrates the volumetric consequences of inadequate recovery of secretory perfusates, and analysis of the perfusion studies shows that distress was significantly associated with poor recovery of the perfusate. These observations are pertinent to increasing interest in the phenomenon of intestinal fluid secretion.

Employing paraprofessional teachers in a group language training program for severely and profoundly retarded children

A study was conducted to evaluate the effectiveness of a newly developed language training program particularly suited for the severely retarded. Designed for use with non-professional staff acting as teachers, the program contains (1) a simplified introduction to operant and modeling procedures, (2) detailed lesson plans, (3) necessary materials, and (4) instructions for testing and evaluation. Institutionalized children classified as severely and profoundly retarded were pretested and assigned to four groups, based on pretest scores. Pairs of children were matched within each group according to pretest performance, language equivalence scores, mental classification, age, sex, race, and behavior problems. One member of each matched pair was then randomly designated an experimental or control child. The experimental groups received 2 mo. of language training (each group comprising one class), with two psychiatric aides conducting all activities. As training was completed, all children were posttested. Comparison of pre- and posttest performances indicated clear treatment effects, demonstrating the potential for wide-spread institutional use of such programs.

Error-detection and correction latencies as a function of S-R compatibility

In choice-response tasks employing correction-procedure, error-correcting responses are typically found to be faster than equivalent correct responses. An experiment was made to compare error-correction RT under conditions of good and poor S-R compatibility in a two-choice task. After practice, variations in S-R compatibility producing significant variations in mean correct RT nevertheless have no effect on error-correction time. The contrast between this result, and one previously reported (Burns, 1965) leads to a re-discussion of the processes of error detection and correction.

Learning set in squirrel monkeys as affected by pretraining with differentially rewarded single objects

The possibility of developing discrimination learning set (LS) by some method other than discrimination training was investigated. In Phase I, 3 groups were given LS pretraining with single objects. Two groups were presented 500 objects, each for 6 trials; one group was rewarded at a 50% random rate, the other at a 100% rate. A third group encountered one object throughout Phase I with all trials rewarded. Their Phase II LS performances were compared with an LS control condition. No pretraining group exhibited LS at the beginning of Phase II. The pretraining group having a 50% random reward rate was significantly suppressed in developing LS. Thus, (a) LS in squirrel monkeys is dependent upon the processes of discrimination learning; (b) the rate at which LS is formed may involve expectancies concerning probable reward rate.