EMERGENCE OF REINFORCER PREFERENCE AS A FUNCTION OF SCHEDULE REQUIREMENTS AND STIMULUS SIMILARITY

Tustin (1994) recently observed that an individual's preference for one of two concurrently available reinforcers under low schedule requirements (concurrent fixed-ratio [FR] 1) switched to the other reinforcer when the schedule requirements were high (concurrent FR 10). We extended this line of research by examining preference for similar and dissimilar reinforcers (i.e., those affecting the same sensory modality and those affecting different sensory modalities). Two individuals with developmental disabilities were exposed to an arrangement in which pressing two different panels produced two different reinforcers according to progressively increasing, concurrent-ratio schedules. When two dissimilar stimuli were concurrently available (food and a leisure item), no clear preference for one item over the other was observed, regardless of the FR schedules in effect (FR 1, 2, 5, 10, and 20). By contrast, when two similar stimuli were concurrently available (two food items), a clear preference for one item emerged as the schedule requirements were increased from FR 1 to FR 5 or FR 10. These results are discussed in terms of implications for conducting preference assessments and for selecting reinforcers to be used under training conditions in which response requirements are relatively high or effortful.     

A preventive,psychoeducational approach to increase perceived social support

Investigated the effects of a 13-week preventive, psychoeducational intervention program to improve perceived social support. Fifty-one, low-perceived support, community residents were randomly assigned to an intervention or wait-list control condition. Intervention subjects received training in social skills and cognitive reframing regarding the self and social relations. The intervention led to increased perceived social support from family, but not from friends. As hypothesized by social cognition models, increases in perceived support appeared to be mediated by changes in self-esteem and frequency of self-reinforcement. Further, such changes in cognition about the self were larger than the changes observed for perceived support, suggesting that it may be easier to change cognition about the self than perceptions of support.     

Intuitive Perceptions of Decision-making Strategy: Naive Assessors' Concepts of Integrative Complexity

Although there are measurable differences in integrative complexity among solutions that individuals generate in dealing with problems, it is uncertain to what extent people comprehend, recognize, and have preferences among different levels of complexity. Integrative complexity is a function of differentiation (the perception of several attributes within, or perspectives about, a topic) and integration (combining the differentiated characteristics in an interactive or synthesizing solution). The current paper reports two experiments dealing with how university students perceive, interpret, and choose among solutions differing in complexity. Experiment 1 showed that subjects accurately rated the complexity of described solutions differing along the continuum, but that their assessment of their own responses differed from the results of expert scoring. Their self-estimated complexity was highly correlated with their preferences, and preferred complexity was reliably higher than either expert- or self-assessed complexity of subject-generated solutions. Subjects were able to hypothesize quite accurately about environmental and endogenous factors likely to affect complexity. Experiment 2 found that in response to problem scenarios, solutions selected as being potentially most effective were consistently more complex than solutions that participants considered themselves most likely to use. The idea of complexity seems to be intuitively recognizable and understandable by untrained subjects: They can and do distinguish among problem solutions (self-generated or presented) that vary on that dimension, and are able to assess accurately the effects of relevant variables. Such subjects also share the bias shown by experts in favour of the superiority of more complex approaches.     

Short term Memory Impairment and Arithmetical Ability

We document the dissociation of preserved calculation skills in a patient with impaired auditory short-term memory. The patient (MRF) had a memory span of three digits. Furthermore, he showed rapid decrement in performance of single digits and letters with both auditory and visual presentation in the Brown-Peterson forgetting task. Analysis of his calculation skills revealed a normal ability to solve auditorily presented multidigit addition and subtraction problems such as 173 + 68 and to execute the Paced Auditory Serial Addition Task (Sampson, 1956, 1958; Gronwall, 1977). In addition, his performance on other tests, including arithmetic manipulation of natural numbers, decimals and fractions, approximation, magnitude, ratio, and percentage, appeared to be normal (Hitch, 1978b). It is argued that these findings require a revision of Baddeley and Hitch's (1974) concept of the function of working memory.     

Event-related brain potentials elicited by rhyming and non-rhyming pictures differentiate subgroups of reading disabled adolescents

Event-related brain potentials were recorded while disabled adolescent subjects read and judged whether two sequentially presented pictures had names that rhymed. Subjects with relatively good phonetic skills displayed an N400 priming effect, i.e., a significant reduction in the amplitude of the negative peak, occurring approximately 400 msec post-stimulus, for pictures with names that rhymed with preceding pictures as compared with pictures that had names that did not rhyme with the prime. No such effect was evident for subjects with relatively poor phonetic skills. This lack of an N400 priming effect provides evidence for a reduction in neural capacity and/or activation during phonological processing in the subjects with poor phonological skills. Demonstrating the N400 priming effect to be stronger in one group of reading disabled subjects, compared to another, supports the position that specific subtypes of reading disability exist. In addition to the stronger N400 priming effect, the phonetically stronger group also exhibited an enhanced negativity, from 700 to 1,000 msec after target stimulus onset, compared to phonetically inferior subjects. This finding replicates earlier work and possibly reflects a higher level of confidence in the group with better phonetic skills.     

The order of continuous,partial and nonreward trials and resistance to extinction

In the first experiment rats were given either 16 or 48 nonrewarded or continuously rewarded trials prior to 24 continuously or partially rewarded trials, followed by extinction. Increased resistance to extinction was found for increasing numbers of nonrewarded trials when they were followed by partial reward, but not when followed by continuous reward. Similarly, more continuously rewarded trials followed by partial reward tended to increase resistance to extinction. Because of the theoretical importance of the effect of continuous reward followed by partial, a second experiment was performed where the range of the number of continuously rewarded trials was extended to 0, 48, and 96. Contrary to many theoretical predictions, resistance to extinction increased as a function of increasing amounts of continuous reward.     

Arbitrariness of frustration: Inhibition or instigation effects on aggression

The purpose of the present research was to assess the relative influence of instigation or inhibition in mediating retaliation after arbitrary or non-arbitrary frustration. Sixty-four men were asked to learn a concept that was being taught by a peer. Although all men were frustrated, half were deliberately frustrated while the other half were not deliberately frustrated by the teacher. Following the task, the learner was given the opportunity to prevent the teacher from gaining employment under conditions where his evaluation was either anonymous or to be made public. The results of a 2 × 2 analysis of variance yielded several significant effects. The data revealed that subjects rejected the teacher more when the frustration was arbitrary than when it was non-arbitrary. Moreover, when the evaluation was anonymous, subjects rejected the teacher more than when the evaluation was to be made public. Furthermore, the difference in the amount of rejection expressed between arbitrary and non-arbitrary conditions was greater when the evaluation was anonymous than when it was public. These results were interpreted as demonstrating the greater contribution of instigatory rather than inhibitory factors in expressing aggression following deliberate or non-deliberate frustration.     

TEACHING THE HANDICAPPED TO EAT IN PUBLIC PLACES: ACQUISITION,GENERALIZATION AND MAINTENANCE OF RESTAURANT SKILLS

This study examined classroom-based instruction in restauranting skills for handicapped persons. Three male students were taught each of four skill components in sequential order: locating, ordering, paying, and eating and exiting. Training was implemented in a multiple baseline design across subjects and consisted of modeling and role playing in conjunction with photo slide sequences and a simulated ordering counter. The use of a menu containing general item classes and a finger matching procedure for identifying errors in the delivery of change greatly reduced the reading and math skills necessary to enter and complete the program. Periodic probes were conducted in a McDonald's restaurant prior to, during, and up to one-year following the termination of training. In addition, two probes (overt and covert observation) were conducted in a Burger King restaurant to assess further generalization to a location different from the one depicted throughout training. Results showed that students' performance on restaurant probes improved as a result of training, generalized to novel settings, maintained over an extended period of time, and was comparable to that of a normative sample of nonretarded persons.