EFFECTS OF WITHIN-STIMULUS AND EXTRA-STIMULUS PROMPTING ON DISCRIMINATION LEARNING IN AUTISTIC CHILDREN1

Two different prompting procedures to teach visual and auditory discriminations to autistic children were compared. The first involved presenting an added cue as an extra-stimulus prompt. This required the child to respond to both prompt and training stimulus. The second involved the use of a within-stimulus prompt. This consisted of an exaggeration of the relevant component of the training stimulus and thus did not require that the child respond to multiple cues. The results indicated that (1) children usually failed to learn the discriminations without a prompt, (2) children always failed to learn when the extra-stimulus prompt was employed but usually did learn with the withinstimulus prompt, and (3) these findings were independent of which modality (auditory or visual) was required for the discrimination.     

Selective imitation of the passive construction through modeling

Six 4- to 5-yr-old subjects were exposed to five sessions in which an adult model used passive sentences to describe a set of modeling stimuli. Probe stimuli, which the subjects were asked to describe without benefit of modeling and without selective reinforcement were interspersed among modeling stimuli. A matched group of control subjects received probletrials but no modeling trials. Both groups of subjects were subsequently tested on their ability to comprehend active and passive sentence forms. Every subject in the experimental group produced passive sentences on probe trials even though there was considerable variability in the number of passives produced. No control subject produced passives. The modeling procedure increased the comprehension scores of the experimental group above those of the control group though the scores of both groups were above chance. The results were contrasted with earlier studies in which modeling was ineffective in producing passive usage and in which comprehension of the passive was not demonstrated by even older children.     

Positive contrast obtained in reacquisition following interpolation of nonreinforced or partially reinforced trials

Two experiments investigated the effects of shifting from either nonreinforcement or partial reinforcement (PRF) to continuous reinforcement conditions (CRF). In the first experiment, three groups of rats were given food reinforcement under CRF conditions in a runway followed by regular extinction trials (RE), extinction trials where Ss were delayed for 30 sec before entering the empty goal box (DE), or CRF trials where Ss were delayed for 30 sec before entering the baited goal box (DF). Then all Ss were run on the delayed reinforcement condition (DF). In the final delayed reinforcement condition, group DE ran significantly faster than group DF, reflecting positive contrast. In the second experiment, four groups of rats were trained in a runway to receive either 4% or 18% sucrose reinforcers under either PRF or CRF conditions. Then all Ss were transferred to a Skinner box and bar presses were continuously reinforced, with each S continuing to receive the same sucrose concentration as before. The former PRF Ss, regardless of the reinforcer, bar pressed at a significantly higher rate in the Skinner box than the former CRF Ss. The evidence seemed to favor the view that the effectiveness of a reinforcer is not an absolute, unchanging quantity but rather depends on the historical context in which the reinforcer occurs.     

The importance of subject control in reinforcing brain stimulation

A comparison between the reinforcement strength of self-administered and externally imposed brain stimulation was undertaken. Rats performed on a chain schedule in order to receive brain stimulation, either selfadministered or imposed, during the second component of the chain. Response rates during the first component of the chain schedule indicated that self-stimulation was more reinforcing than imposed stimulation. In addition, contrast, both positive and negative, seemed to be present. It was concluded that reinforcement strength may be enhanced when the subject controls the presentation of reinforcement.     

Comparison of women engineers who persist in or depart from engineering

The current research examined differences between women engineers who persisted in an engineering career versus those who left engineering using a combination of two prominent theories of career change: social cognitive career theory (SCCT, Lent, Brown & Hackett, 1994; 2002) and integrated model of career change (Rhodes & Doering, 1983). The two groups of women did not differ in three domains of self-confidence or outcome expectations (engineering tasks, navigating organizational climate, or multiple roles), in vocational interests, or in workplace barriers. Women who continue in engineering do differ from those who leave in their experience of workplace supports and their levels of occupational commitment. Engineering turnover intentions and occupational commitment emerged as the two key variables that explained 33.4% of the variance in persistence in engineering careers. We discuss the implications of the results in terms of theoretical development and practical implications for organizations.     

Traffic Offences: Planned or Habitual? Using the Theory of Planned Behaviour and habit strength to explain frequency and magnitude of speeding and driving under the influence of alcohol

This study addresses the socio‐cognitive determinants of traffic offences, in particular of speeding and drinking and driving. It has two aims: (1) to test the hypothesis of a direct effect of habits on offences (i.e., independent of intentions) by employing a specific measure of habits (i.e., the SRIH) and (2) to analyse the offences by taking account of three distinct parameters: Frequency, usual magnitude (i.e., the most frequent deviation from the law) and maximal magnitude (i.e., the greatest deviation occasionally adopted) in order to represent more accurately the variability of the offending behaviours. A total of 642 drivers replied to a questionnaire. The results corroborate the idea that intention and habit are distinct and direct determinants of offences. The use of the SRIH dismisses the criticisms made with regard to the measure of past behaviour. The distinction between the three behavioural parameters proves to be relevant, as their determinants are not exactly similar. Finally, attitude and subjective norm had direct effects on the maximal magnitude and/or on the frequency of the offence. The discussion concerns the contribution of this study to the analysis of offences as well as its limitations and addresses the theoretical plausibility of the direct effects of attitude and the subjective norm.