ASSESSMENT AND TREATMENT OF DESTRUCTIVE BEHAVIOR MAINTAINED BY STEREOTYPIC OBJECT MANIPULATION

In the current investigation, 2 participants with mental retardation displayed property destruction and stereotypy, and both responses involved the same materials (e.g., breaking and tapping plastic objects). Three experiments were conducted (a) to indirectly assess the functions of these two responses, (b) to determine their relation to one another, and (c) to develop a treatment to reduce the more serious behavior, property destruction. In Experiment 1, previously destroyed materials were either present or absent, and their presence reduced property destruction but not stereotypy. In Experiment 2, matched toys (ones that produced sensory stimulation similar to stereotypy) were either present or absent, or were replaced by unmatched toys (for 1 participant). Matched toys produced large reductions and unmatched toys produced small reductions in property destruction and stereotypy. In Experiment 3, attempts to pick up undestroyed objects were either blocked or not blocked while matched toys were continuously available. Response blocking reduced property destruction (and attempts), prevented stereotypy, and increased manipulation of matched toys. These results suggest that the two aberrant responses formed a chain (e.g., breaking and then tapping the object), which was maintained by the sensory consequences (e.g., auditory stimulation) of the terminal response, and that previously destroyed material or matched toys made the initial response (property destruction) unnecessary.     

Touch dominates haptic estimates of discordant visual-haptic size

Observers (72 college students) estimated the size of plastic squares that they held in their fingers and simultaneously viewed through a reducing lens that halved the squares’ visual size. The squares were grasped from below through a cloth that prevented direct sight of the hand. Each estimate was a match selected later, either haptically or visually, from a set of comparison squares. Vision dominated the visual estimates and touch dominated the haptic estimates, whether or not the observers knew in advance which type of estimate they would be asked to make. Neither modality inherently dominates perceived size.     

Communicative stress and stuttering frequency during normal,whispered, and articulation-without-phonation speech modes

The effect of communicative stress on the frequency of stuttered syllables in 12 adult stutterers reading six different but equivalent passages using normal voicing, whispering, and articulation-without-phonation speech under a stress and a non-stress condition was studied. Although the frequency of stuttering was significantly greater in the normal voicing mode than in the whispering mode and greater in the whispering mode than in the articulation-without-phonation mode, no differences were found between the stress and the nonstress conditions with respect to stuttering.     

Effect of effort and latent extinction on resistance to extinction

Sixty-four male Wistar rats were given acquisition training in an enclosed straight-alley runway which could be adjusted for angles of inclination. The 2×2×2 design involved two angles of inclination in acquisition (0° and 40°) and two angles of inclination in extinction (0° and 40°). Between acquisition and extinction, half the subjects were exposed to a latent extinction procedure and half served as controls. Number of responses in a 30-min extinction session was an inverse function of effort required in extinction. Additionally, latent extinction procedures resulted in reduced resistance to extinction, but only when the effort conditions of acquisition and extinction were constant. When the effort conditions of acquisition and extinction were dissimilar, latent extinction procedures resulted in increased resistance to extinction. The results raise questions about the nature of the learning which occurs during latent extinction training.     

The Attraction-Leniency Effect in Jury Research: An Examination of External Validity

The external validity of the attraction-leniency effect observed repeatedly in jury research was examined by adding two small elements of juridicial realism to the usual paradigm modeled after Landy and Aronson (1969). An attraction-leniency effect was not found when judge's instructions regarding the criteria of guilt were provided, and subjects assessed probable guilt rather than appropriate sentence.     

Verbal and nonverbal recognition memory in aphasic and nonaphasic stroke patients

The ability to retain lists of verbal and nonverbalizable items across recurrent recognition tasks was tested in three groups: (1) stroke patients with a left-brain lesion and aphasia, (2) stroke patients with a right-brain lesion and left hemiplegia, and (3) nonneurologically impaired outpatients. As determined with signal detection measures, aphasics were deficient in discriminating words that were to be remembered from those that were not; their recognition of nonverbal visual (geometric art) or auditory (bird calls) patterns, however, was unimpaired. Left hemiplegics showed the opposite pattern. After a long-term interval (<10 min), correct recognition of words was diminished in all groups whereas recognition of visual patterns increased. Both groups of stroke patients adopted material-specific decision criteria which in part accounted for the dissociation of verbal and nonverbal recognition memory by laterality of lesion. Item analysis indicated that aphasics' verbal memory difficulties were affected by acoustic-semantic confusion of list words.     

Context and repetition effects in recognition memory

The demonstration of a repetition effect in recognition memory when context at the time of test is different from that occurring during presentation places limits on the role played by context in interpretations of recognition memory. Four experiments are reported that explore those limits, including a situation in which the repetition effect does not obtain due to the nature of the context. The data are interpreted in terms of the important interaction between item information and contextual information in theoretical accounts of recognition memory.     

Practical and scientific rationality: A difficulty for Levi's epistemology

Traditionally scientific rationality has been distinguished from mere practical rationality. It has seemed that it is sometimes rational to accept statements for the purposes of particular practical deliberations even though it would not be rational to count them as having been confirmed by science. Isaac Levi contends that this traditional view is mistaken. He thinks that there should be a single standard of acceptance for all purposes, scientific and practical. The author contends that Levi has given no good reason for identifying scientific with practical rationality. And he argues that Levi's own theory is inconsistent with the thesis that a scientist should use a single standard of acceptance in all his scientific deliberations.