Non-aversive reduction of cigarette smoking in two adult men in a residential setting.

Two middle-aged men with mental retardation, addicted to smoking cigarettes, operated spinners that determined the probability with which they could obtain cigarettes and other items. Absence of several maladaptive behaviors permitted the operation of the spinners hourly (i.e., DRO 60 min), 16 h per day, 7 days per week. The actual frequencies of obtaining cigarettes followed the theoretical probabilities of obtaining cigarettes in all phases of the study. Presumed smoking frequencies were reduced by about 50% with associated medical benefits. Low frequencies of maladaptive behaviors were maintained throughout.

Themes, taxons, and trial types in children's matching to sample: methodological considerations.

Five experiments were conducted in which preschool children (29-73 months) matched pictures of common objects. Each trial consisted of a sample and two comparison pictures (all three together defined as a trial type) in which the sample was related to one comparison taxonomically and to the other thematically. The intent of each experiment was to replicate results in the literature in which young children more readily relate objects thematically than taxonomically. Instead, in all five experiments the children more often selected the taxonomic comparisons. These results occurred independently of age, gender, instructions, order of the trial types, nonspecific performance feedback, the presence of a third comparison unrelated to the sample, and the level of the taxonomy (superordinate vs basic). Instructions to select a comparison that was the same as the sample increased responses to the taxonomic comparisons. Comparison selection in this task relates both to the individual trial type and the individual subject.

Observation and measurement of drooling by people with mental retardation.

Four brief observational surveys were used to score residents of a state institution for people with mental retardation as drooling/not drooling. An average of 14% of the population was identified as drooling on the occasion of any of the surveys; the accumulated proportion of clients reported as drooling was 28%. In a second study, the drooling of 2 of the clients identified in the first study was sampled within and across days. These clients drooled different amounts both within and between days, which validated their presence and classifications in the first study.

Sundown syndrome: is it reflected in the use of PRN medications for nursing home residents?

Sundown syndrome describes the increase in agitation and delirium in elderly patients with dementia that occurs in the evening after sunset. In a nursing home, data were gathered over a year-long period to test the hypothesis that the administration of PRN (pro re nata, given as needed) medications for agitation in Alzheimer's patients would reflect sundown syndrome. More PRNs were administered in the early morning and mid-afternoon hours than at other times of the day. These outcomes suggest there is a relationship of PRN use for agitation, in institutionalized Alzheimer's patients, to environmental variables other than sunset.

Ontogeny of proenkephalin mRNA and enkephalin peptide expression in the cerebellar cortex of the rat: spatial and temporal patterns of expression follow maturational gradients in the external granular layer and in Purkinje cells.

Proenkephalin mRNA and peptide products were examined in developing cells of the postnatal rat cerebellar cortex using in situ hybridization and immunocytochemistry. On day 7, proenkephalin mRNA was first detected as discrete cellular labeling in Golgi cells and as a diffuse hybridization signal over the Purkinje cell layer. On day 14, proenkephalin mRNA and peptide products primarily appeared in distinct subpopulations of Purkinje cells present in the posterior and lateral cerebellum. Similarly, in the external granular layer (EGL), enkephalin immunoreactivity was present only in the posterior and lateral portions of the cerebellum on day 14. However, proenkephalin mRNA was not detected in enkephalin-immunoreactive EGL cells. On day 21, the subset of Purkinje cells that expressed proenkephalin mRNA and peptides were distributed more uniformly throughout the cerebellum. On day 28, a few enkephalin-immunoreactive Purkinje cells were uniformly present throughout the cerebellum, but proenkephalin mRNA was not detected in most of these cells. The spatial gradients in proenkephalin mRNA expression evident in the Purkinje cells of younger rats were no longer present in 28-day-old rats. These findings are important, because endogenous opioids such as enkephalin have been previously shown to inhibit the growth of Purkinje cell dendrites and dendritic spines, and inhibit the rate of mitosis in EGL neuroblasts. Cells do not develop at uniform rates within the cerebellum. There are regional differences in the timing of the formation of the EGL, and in the morphogenesis of Purkinje cells. In conjunction with previous work, the present findings suggest that during development, the pattern of enkephalin immunoreactivity in Purkinje and EGL cells closely follows the spatial and temporal gradients of maturation in both these cell types. The emergence and disappearance of enkephalin immunoreactivity in Purkinje and EGL cells is spatially and temporally related, and coincides with proenkephalin mRNA expression in Purkinje cells. Thus, the transient and coordinated appearance of enkephalin in cerebellar Purkinje and EGL cells may contribute to regional differences in the rate of cerebellar maturation, and may help synchronize the developmental interactions between these two cell types.

Cyclical self-injurious behavior, contingent water mist treatment, and the possibility of rapid-cycling bipolar disorder.

Cyclical self-injurious behavior (SIB) in the form of self-slapping was treated in a 45-year-old, profoundly retarded woman who had a life-long history of SIB. Her SIB alternated between high (mean = 8.54 responses per min; SD = 6.77 and low (mean = 0.05 responses per min; SD = 0.20) frequencies every 8 weeks on average. Instances of self-slapping produced water mist treatment paired with a verbal command, "No hitting". Absence of self-slapping and/or completion of a work task led to a variety of outcomes, including brief back rubs, sips of water, small edibles, and praise. Water mist treatment reduced the frequency of SIB within treatment days during high frequency periods, but produced no reduction across treatment days. Treatment onset was associated with a slight increase in the frequency of SIB during three of the five low frequency periods. However, water mist treatment suppressed SIB completely in sessions during low frequency periods and the suppression continued across treatment days. Water mist treatment produced no discernible changes in the length of the high and low frequency periods of SIB.

Expression of proenkephalin mRNA in developing cerebellar cortex of the rat: expression levels coincide with maturational gradients in Purkinje cells.

The cellular localization of proenkephalin (PE) mRNA expression was systematically examined in midsagittal (vermal) sections of the developing rat cerebellar cortex by in situ hybridization. PE mRNA was initially detected in Golgi cells of postnatal day 7 (PND 7) rats and in each group thereafter. Moreover, PND 7 rats also displayed an intense layer of PE mRNA hybridization signal over the Purkinje cell layer. By PND 14, distinct cellular labeling was observed in a subpopulation of Purkinje cells in all lobules of the vermis except lobule III. At PND 7 and 14, the area and level of intensity of Purkinje cell associated PE mRNA hybridization signal followed a gradient that was most intense caudally but then decreased rostrally. At PND 21, the proportion of labeled Purkinje cells and the intensity of PE hybridization signal was evenly dispersed between the anterior and posterior lobules of the cerebellar vermis. PE hybridization signal was not detected in the developing neural cells of the external granular layer or the interneurons of the molecular layer in the vermis. These results indicate that the ontogeny of PE mRNA expression in Purkinje cells is developmentally regulated since levels of expression closely follow the chronological order of settling and maturation of these neurons. Based on prior evidence that endogenous opioids inhibit the growth of Purkinje cell dendrites and dendritic spines, PE expression is likely to be important for Purkinje cell maturation.

The use of contingent water misting in the treatment of self-choking.

A 25-year-old, deaf-blind, mentally retarded male was treated for chronic self-choking using water mist treatment and positive reinforcement. During pre-treatment baseline, self-chokes occurred at a rate of 2.09 per minute. During treatment sessions each self-choke was followed by water misting of the subject's face paired with a forceful "No!". Periods of 20 sec absent of self-chokes were positively reinforced with liquids and/or social contacts. Treatment procedures were generalized from the initial therapists, location, and absence of other clients and staff to other locations, and the presence of other clients and staff. Water mist treatment was associated with at least a 10-fold and as much as a 100-fold reduction of self-choking (i.e. to 0.02-0.20 self-chokes per min) across treatment and generalization phases. Eight-month follow-up observations showed that self-choke rates were at zero.

Co-localization of proenkephalin mRNA using cRNA probes and a cell-type-specific immunocytochemical marker for intact astrocytes in vitro.

To determine whether cultured astrocytes express opioid gene mRNA, a method was developed for co-localizing a cell-type specific immunocytochemical marker for astrocytes, glial fibrillary acidic protein (GFAP), and proenkephalin mRNA in situ hybridization signal using high affinity cRNA probes. GFAP immunoreactivity and proenkephalin mRNA hybridization reaction were examined in intact glial cell preparations from neonatal mice that were cultured for 4-6 days prior to fixation. The double labelling method described herein permits the unambiguous identification of mRNA expression in specific populations of intact cultured cells using cell type-specific markers.

Cellular localization of proenkephalin mRNA and enkephalin peptide products in cultured astrocytes.

To identify the possible cellular sites of opioid gene expression during ontogeny, proenkephalin mRNA and enkephalin peptide expression were examined, respectively, by in situ hybridization and immunocytochemistry in organotypic explants of rat cerebellum and in astrocyte-enriched cultures of murine cerebral hemispheres. High levels of proenkephalin mRNA and enkephalin immunoreactivity were detected in immature cells identified as astrocytes. Double-labeling studies combining in situ hybridization and immunocytochemical localization of the astrocytic marker, glial fibrillary acidic protein, provided direct evidence that proenkephalin mRNA is expressed by astrocytes in culture. Based on previous studies that Met-enkephalin can inhibit astrocyte growth in vitro, the present results suggest that proenkephalin gene expression by astrocytes is important during central nervous system maturation.

Transfer of contextual stimulus function via equivalence class development.

In a conditional discrimination, 6 college students arranged six Cyrillic letters into groups of three based upon which of two additional Cyrillic letters (contextual stimuli) was present. All subjects demonstrated symmetry and transitivity within each class of equivalent stimuli. In a second conditional discrimination, two more Cyrillic letters were related to each contextual stimulus. Testing of symmetrical and transitive relations between the original contextual stimulus and the two new ones confirmed the development of two three-member classes of contextual stimuli. Subsequent tests demonstrated that the new contextual stimuli controlled the previously trained sample-comparison relations for all subjects.

Control of behavior by an establishing stimulus.

Seventeen pigeons were exposed to a three-key discrete-trial procedure in which a peck on the lit center key produced food if, and only if, the left keylight was lit. The center key was illuminated by a peck on the lit right key. Of interest was whether subjects pecked the right key before or after the response-independent onset of the left keylight. Pecks on the right key after left-keylight onset suggest control of behavior by the left keylight-an establishing stimulus. In three experiments, the strength of center-keylight onset as conditioned reinforcer for a response on the right key was manipulated by altering the size of the reduction in time to food delivery correlated with its onset. Control of pigeons' key pecks by onset of the left keylight occurred on more trials per session when the center keylight was a relatively weak conditioned reinforcer and on fewer trials per session when the center keylight was a relatively strong condtioned reinforcer. Differences across conditions in the degree of control by onset of the establishing stimulus were greatest when changes in conditioned reinforcer strength occurred relatively frequently and were signaled. The results provide evidence of the function of an establishing stimulus.

A citation analysis of the influence on research of Skinner's verbal behavior.

The influence of Skinner's Verbal Behavior on the generation of verbal behavior research was examined in a citation analysis that counted the citations of the book from January 1957 to August 1983 and described the fields in which the citations occurred. In a subsequent content analysis, citations were classified as directly influenced by the book if they selected at least one of Skinner's classes of verbal behavior for empirical examination. Directly influenced citations were sorted as descriptive, applied, or basic. The total number of citations of the book (836), the increasing annual number of citations, and the range of fields in which the book has been cited are evidence of its broad influence. However, empirical investigations employing at least one of Skinner's classes of verbal behavior are only a small proportion (31/836) of the citations. Of this small proportion an even smaller number constitutes experimental analyses (19/836). The small proportion of empirical studies suggests that Verbal Behavior is primarily cited for reasons other than as source material for research hypotheses in the study of verbal behavior. Some speculations are offered to account for the book's limited influence on research.

Control of adolescents' arbitrary matching-to-sample by positive and negative stimulus relations.

In Experiment 1, four developmentally delayed adolescents were taught an A-B matching-to-sample task with nonidentical stimuli: given Sample A1, select Comparison B1; given A2, select B2. During nonreinforced test trials, appropriate matching occurred when B stimuli appeared as samples and A stimuli as comparisons, i.e., the sample and comparison functions were symmetrical (B-A matching). During A-B or B-A matching test trials in which familiar samples and correct comparisons were presented along with novel comparisons, the subjects selected the correct comparisons. In tests with familiar samples and both incorrect and novel comparisons, subjects selected the novel comparisons, demonstrating control by both positive ("matching") and negative ("nonmatching") stimulus relations in A-B and B-A arrays. In Experiment 2, 12 developmentally delayed subjects were taught a two-stage arbitrary-matching task (e.g., A-B, C-B matching). Test sessions showed sample-comparison symmetry (e.g., B-A, B-C matching) and derived sample-comparison relations (e.g., A-C, C-A matching) for 11 subjects. These subjects also demonstrated control by positive and negative stimulus relations in the derived relations.

Fixed-ratio and fixed-interval schedule control of matching-to-sample errors by children.

Nine children, ages 4 through 7 yr, matched-to-sample on fixed-ratio, fixed-interval, variable-ratio, and variable-interval schedules of reinforcement. Simultaneous, zero-delay, and 2-sec delay matching were employed. Distributions of errors, in which the greatest number of errors occurred at the ordinal position immediately after reinforcement with fewer errors occurring at subsequent positions in the ratio, were produced by six of six children on fixed-ratio schedules for zero-delay and both of two children for 2-sec delay matching. Only two children of seven produced similar error distributions on simultaneous matching for fixed-ratio reinforcement. Variable-ratio schedules produced slightly lower accuracy for most subjects and no systematic error patterns for any subject. Error distributions occurred for all of the five children who experienced fixed-interval schedules for zero-delay matching. Peak error production occurred in the second fourth of the interval. Similar patterns were not produced on variable-interval schedules of equal reinforcement density. Schedule control of complex discriminated operants in children resembles control over similar responses of nonhuman animals.