Interaction of reinforcement schedules, a behavioral prosthesis, and work-related behavior in adults with mental retardation

The effects of variable-interval (VI) and fixed-ratio (FR) schedules of reinforcement for work-related behavior and an organizer for the work materials (behavioral prosthesis) were evaluated with 3 adults with severe or profound mental retardation. The participants had been recommended for study because of high rates of off-task and aberrant behavior in their daily vocational training programs. For 2 participants, VI and FR schedules resulted in the same outcome: more aberrant behavior than on-task and off-task behavior combined. The FR schedule nearly eliminated emission of aberrant and off-task behavior by the 3rd participant. Combining the behavioral prosthesis with FR reinforcement (FR+O) increased the proportion of time spent in on-task behavior by all participants under certain FR schedule parameters. Second-by-second analyses of the observation records revealed that FR schedules reduced off-task and aberrant behavior during work sequences (i.e., ratio runs), and FR+O led to a further reduction of these behaviors during postreinforcement pauses. Overall, the results show how organizer and schedule parameters can be adjusted to produce an optimized balance between productivity and reinforcement while undesirable behavior is minimized.     

Bilingual Children’s Narrative Comprehension: Do Pauses during Retelling Buy Time for Understanding?

Abstract

This study extended research on bilingual children’s narrative comprehension to text processing during retelling. A cross- and monolinguistic design allowed for the investigation of the association of various aspects of narrative comprehension with two types of pause occurring during oral retelling of a story heard in one language and retold in a second or in the same language. A sample of 95 bilingual (L1 German/L2 English) fourth-graders participated in the experiment. Comprehension was predominantly accomplished during listening, as children with L1 input outperformed children with L2 input, but they did not benefit from L1 in retelling. Children’s comprehension performance and corresponding pause patterns suggested that the duration of filled pauses dedicated to gist formation indicated efficiency of comprehension: The duration decreased with increasing comprehension. The findings allowed the conclusion that longer pauses during retelling did not buy time for comprehension.     

Effects of chlordiazepoxide on pausing during rich-to-lean transitions

Extended pausing during discriminable transitions from rich-to-lean conditions can be viewed as escape (i.e., rich-to-lean transitions function aversively). Thus, an anxiolytic drug would be predicted to mitigate the aversiveness and decrease pausing. In the current experiment, pigeons' key pecking was maintained by a multiple fixed-ratio fixed-ratio schedule of rich (i.e., larger) or lean (i.e., smaller) reinforcers. Intermediate doses (3.0-10.0 mg/kg) of chlordiazepoxide differentially decreased median pauses during rich-to-lean transitions. Relatively small decreases in pauses occurred during lean-to-lean and rich-to-rich transitions. Effects of chlordiazepoxide on pausing occurred without appreciable effects on run rates. These findings suggest that signaled rich-to-lean transitions function aversively.