Echoic and self-echoic responses in children.

Eleven typically developing children were assessed on the accuracy of prompted self-echoic responses following a 5-s delay from their initial echoic response, replicating procedures in Esch, Esch, McCart, and Petursdottir (2010) that compared discrepancies between echoic and self-echoic scores of autistic and typically developing children following a 2-s delay. We compared the two studies in terms of age, level tested, and echoic/self-echoic discrepancy scores. Age and test level differences were found to be statistically significant. Results are discussed in terms of discrepant self-echoic performance and self-echoic rehearsal as it relates to participant age, test level, motivating variables, and the development of complex behavior.

The role of common motor responses in stimulus categorization by preschool children.

The purpose of this study was to assess the role of common motor responses as the "speaker" behavior on stimulus class formation, and the emergence of functional classes. Experiment 1 examined whether training one motor response to a set of three stimuli and a second motor response to another set of three stimuli would result in correct category-sort responses for 5 typically developing preschool children. Three of the children passed the categorization tests. Experiment 2 examined whether the classes formed in Experiment 1 were functional classes, and whether participants who did not pass categorization tests in Experiment 1 would do so following common vocal tact training. The 2 participants who failed categorization tests in Experiment 1 passed these tests in Experiment 2, although none of the participants passed the tests for functional classes. The results of the current study did not unequivocally support the naming hypothesis. Future research should therefore evaluate other possible sources of control that aid in stimulus categorization.

Using giant African pouched rats to detect tuberculosis in human sputum samples: 2010 findings.

Giant African pouched rats previously have detected tuberculosis (TB) in human sputum samples in which the presence of TB was not initially detected by smear microscopy. Operant conditioning principles were used to train these rats to indicate TB-positive samples. In 2010, rats trained in this way evaluated 26,665 sputum samples from 12,329 patients. Microscopy performed at DOTS centers found 1,671 (13.6%) of these patients to be TB-positive. Detection rats identified 716 additional TB-positive patients, a 42.8% increase in new-case detection. These previously unreported data, which extend to over 20,000 the number of patients evaluated by pouched rats in simulated second-line screening, suggest that the rats can be highly valuable in that capacity.