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J Sigafoos

Publications and source records attributed to J Sigafoos.

34 records · Page 2Linked to original sources
PubMed1994

A survey of aggressive behaviour among a population of persons with intellectual disability in Queensland.

A survey was conducted on aggressive behaviour within a population of 2412 persons with intellectual disability in Queensland, Australia. Two hundred and sixty-one individuals were identified who engaged in at least one form of aggressive behaviour, yielding an overall prevalence of 11%. The relative prevalence of aggressive behaviour was higher among institutionalized persons (35%) when compared to those living in group homes (17%) or other community-based facilities (3%). The aggressive behaviour sample included a higher percentage of males (64%). Most were described as functioning in the severe/profound (54%) or moderate (31%) range of intellectual disability with one-third having no intelligible speech. Two-thirds of the sample received medication for their challenging behaviour, while only one-third had behavioural programmes. Eighty per cent engaged in three or more forms of aggression. Many also displayed self-injury (34%) or property destruction (30%). Surveys of aggressive behaviour may prove useful for coordinating services.

Adolescent↗
PubMed1993

Identification of a 7B2-derived tridecapeptide from bovine adrenal medulla chromaffin vesicles.

1. A novel tridecapeptide was isolated from extracts of bovine adrenal medulla chromaffin vesicles and the primary structure determined to be SVPHFSDEDKDPE. 2. This peptide is identical to the C termini of human and porcine 7B2 and is highly homologous to the same region of the mouse and Xenopus lavis protein. 3. In all these species the homologous peptide is preceded by a pair of lysine residues, a potential proteolytic processing site. 4. Ser6 is part of a well-conserved casein kinase II consensus phosphorylation sequence. Evidence for phosphorylation of this residue was obtained during Edman sequencing. 5. Thus, this novel adrenal medullary probably arises from the posttranslational processing of the bovine 7B2 protein.

Adrenal Medulla↗
PubMed1993

Novel peptides from adrenomedullary chromaffin vesicles.

The adrenal medulla chromaffin vesicle (CV) contains, on a weight basis, as much soluble protein and peptide as catecholamine. The bulk of the protein is accounted for by chromogranins (Cgr) A, B and C. Additionally, a large variety of neuropeptides and their precursor proteins have been found recently within these vesicles. Nevertheless, fractionation of CV lysates indicates the presence of many more peptides than previously reported. In the hope of finding novel bioactive peptides, we initiated a systematic isolation and characterisation of CV peptides. Bovine CV pellets were prepared by sucrose gradient centrifugation and immediately boiled in water to avoid degradation of native proteins and peptides. The water lysates were fractionated through a battery of reversed-phase and ion-exchange high-performance chromatographic steps. We fully or partially characterised a substantial number of novel peptides derived from CgrA and CgrB. A tetradecapeptide and a 13 kDa extended peptide were derived from the bovine homologue of rat secretogranin III. Peptides corresponding to C-terminal fragments of 7B2 and proteoglycan II were also found. Additionally, several sequences had no known precursors. Of the sequences derived from known precursors some corresponded to fragments bracketed by pairs of basic amino acids, but others were preceded or followed by single basic residues or by unusual putative cleavage sites. Some of these peptides were postranslationally modified (pyroglutamylation, glycosylation, phosphorylation, amidation). A significant degree of structural conservation of some of these peptides across species suggests that they may exert biological effects when cosecreted with catecholamines during splanchnic stimulation.

Adrenal Medulla↗
PubMed1992

Assessing choice making among children with multiple disabilities.

Some learners with multiple disabilities display idiosyncratic gestures that are interpreted as a means of making choices. In the present study, we assessed the validity of idiosyncratic choice-making behaviors of 3 children with multiple disabilities. Opportunities for each child to choose between food and drink were provided under two conditions. In one condition, the children were given the food or drink item corresponding to their prior choice. In the other condition, the teacher delivered the item opposite to that chosen. It was reasoned that valid choice-making behaviors would be reflected in a greater tendency to accept the chosen item and refuse the unchosen item. Direct observations revealed all children consistently indicated choices during both conditions. Choices of both the food and drink items were made by all 3 children. A reversal design demonstrated that acts of refusal were more frequent when choices were followed by delivery of the item opposite to that chosen. Similar assessment procedures may be effective in determining the function of idiosyncratic gestures exhibited by persons with multiple disabilities. For children lacking such skills, intervention to teach valid choice-making behaviors may be needed to complement assessment procedures.

Child↗
PubMed1990

"Spontaneous" transfer of stimulus control from tact to mand contingencies.

An important issue in teaching verbal behavior to persons with severe handicaps is the transfer of stimulus control from tact (e.g., naming) to mand (e.g., requesting) relationships. Previous research has shown that topographies taught as tacts frequently fail to appear as mands unless transfer between these two response classes is explicitly programmed. Procedures promoting this transfer would provide a necessary instructional tool. Transfer from tact to mand contingencies was investigated in two adults with severe mental retardation. Correct pointing responses to line drawing symbols depicting the utensils required to access previously requested food (beverage) items were assessed prior to and following tact intervention. Mands for two of three utensils emerged following tact intervention. The results suggest transfer from tact variables to the conditioned establishing operation may be facilitated by the prior development of a minimal mand repertoire.

Adult↗
PubMed1989

Developing mand and tact repertoires in persons with severe developmental disabilities using graphic symbols.

An important educational objective for many persons with developmental disabilities is the acquisition of verbal operants such as the mand (e.g., requesting) and tact (e.g., labeling). Mands and tacts have been described as separate response classes and several studies support this description. Consequently, an important applied issue involves implementing procedures to develop both tact and mand repertoires. The present study investigated procedures for developing mands and tacts in three learners with severe disabilities. Learners were first taught to tact, then mand food/beverage items and the utensils required to access those items by pointing to line drawings depicting the items. The results suggest that responses acquired as tacts do not readily occur as mands. "Spontaneous" manding was developed through a transfer of stimulus control procedure which brought mands under the control of conditioned establishing operations. Substantial transfer to untrained objects and transfer across response classes were frequently noted after both tact and mand interventions had occurred for some items. Variables facilitating these generalized effects are discussed.

Adult↗
PubMedDate not supplied

Interrater reliability of the Motivation Assessment Scale: failure to replicate with aggressive behavior.

The Motivation Assessment Scale (MAS) was used to identify the variables maintaining aggressive behaviors exhibited by 18 adolescents and adults with severe to profound intellectual disability. Each client was rated by two staff members. A variety of measures were calculated to assess interrater reliability. Pearson coefficients across the 18 pairs of raters ranged from -.667 to .722 with an overall correlation of .034. Five of the 12 positive correlations were significant at the .05 level. Correlations across each of the 16 questions of the MAS ranged from -.337 to .425. None of these correlations were significant. Similarly low reliability was obtained when percentage of agreement measures were calculated, although 8 of the 18 pairs of raters (44.44%) did agree on the source of reinforcement maintaining the client's aggressive behavior. These results suggest that for some individuals the MAS may not represent a viable alternative to more formal functional analysis procedures.

Adolescent↗
PubMedDate not supplied

A review of the nature and treatment of sleep disorders in individuals with developmental disabilities.

This paper describes research on the prevalence, correlates, and treatment of sleep disorders in individuals with developmental disabilities. A significant number of individuals with developmental disabilities have disordered sleep, although prevalence estimates vary from 13% to 86%. Constitutional variables, including age, presence of physical and sensory impairments, and certain genetic syndromes and medical conditions appear to be related to sleep disturbance, but the evidence is mainly correlational and therefore cannot be said to show a causal relation. While a number of behavioral interventions have proven effective in the treatment of sleep disturbance, and drug therapy involving melatonin appears promising, epidemiologic work on the correlates of sleep disorders appear to have had little impact on treatment. Consideration of the nature of sleep disorders may enhance treatments for individuals with developmental disabilities.

Behavior Therapy↗
PubMedDate not supplied

The Motivation Assessment Scale: reliability and construct validity across three topographies of behavior.

The psychometric properties of the Motivation Assessment Scale (MAS) were examined. Specifically, reliability, internal consistency, and construct validity were estimated using 90 ratings of different problem behaviors among 86 individuals with mental retardation. Data were analyzed under conditions of (a) three topographies of problem behavior and (b) two methods of calculation. Although reliability and internal consistency were generally poor, the results depended upon the above conditions. Factor analysis revealed that the four factors of the MAS differed from the subscale structure obtained in this study, proposed by the authors of the MAS. Thus, the construct validity of this scale was ambiguous. It is concluded that the MAS should be employed in conjunction with other instruments to assess the functional characteristics of problem behavior with individuals who have mental retardation.

Group Homes↗
PubMedDate not supplied

Longitudinal assessment of play and adaptive behavior in young children with developmental disabilities.

Deficits in appropriate play have been widely documented among children with developmental disabilities. However, there has been little research on the development of play or the relation between play and adaptive behavior in such children. The present study involved a longitudinal assessment of play and adaptive behavior among 13 preschool children with developmental disabilities. Children were assessed every 6 months over a 3-year period. Assessments included standardized ratings of adaptive behavior and videotape observations during unstructured free-play times in the preschool classroom. Adaptive behavior increased by almost one standard deviation from the first to the last round of data collection. Appropriate play was observed during approximately 20% of each 30-min observation and showed little overall change over 3 years of study. Observed play was primarily functional (57%) and exploratory (28%) with less constructive (5%) and pretend (10%) play. Adaptive behavior scores were not consistently correlated with the amount or type of play. The results suggest little overall relation between appropriate play and other major domains of adaptive behavior. Implications for play-based assessment and intervention in early childhood special education are discussed.

Autistic Disorder↗
PubMedDate not supplied

Evaluating a computer system used as a microswitch for word utterances of persons with multiple disabilities.

PURPOSE: To assess the effectiveness of a computer system used as a microswitch for word utterances of two adults with multiple disabilities. The system combined a new control software programme with a commercially available speech recognition programme. METHOD: Nine word utterances were targeted for each participant. The participant's emission of those utterances triggered the occurrence of related (favourite) stimuli during the intervention and the post-intervention check. RESULTS: Intervention data showed that (1) the participants increased the frequencies of the target utterances and (2) the computer system recognized about 80% of those utterances correctly, providing the participants with high levels of favourite stimulation. The post-intervention check showed comparable data with both participants. CONCLUSIONS: The computer system proved an adequate microswitch for word utterances. Based on this evidence, microswitch programmes could be extended beyond the use of conventional motor responses.

Abnormalities, Multiple↗
PubMedDate not supplied

Enabling a person with multiple disabilities and minimal motor behaviour to control environmental stimulation with chin movements.

PURPOSE: To assess whether a young man with multiple disabilities and minimal motor behaviour would learn to control environmental stimulation using chin movements and a mechanical microswitch. METHOD: The study was carried out according to an ABAB design in which A represented baseline and B intervention phases. The chin movements controlled the stimulation only during the intervention phases. A 2-month post-intervention check was conducted. RESULTS: The man increased the frequency of his chin movements, thus increasing the level of environmental stimulation, during the intervention phases. This performance was maintained at the post-intervention check. CONCLUSION: The use of chin movements is a practical strategy for enabling individuals with minimal motor movements to control environmental stimulation. Future research should examine whether similar types of movements may enable some individuals to control voice-output communication devices.

Abnormalities, Multiple↗
PubMedDate not supplied

Transferring AAC intervention to the home.

PURPOSE: To evaluate the acquisition of AAC skills during an initial clinical trial and assess subsequent transfer of the training to the home setting. METHOD: A 12-year-old male with autism was first seen in a clinical setting to establish the use of a voice-output communication device. After learning to use the device to request access to preferred objects in the clinical trial, the intervention was transferred to the home. Follow-up with the parent was conducted via e-mail and telephone. Videotapes were made of initial home-based sessions to enable evaluation of the participant's progress. RESULTS: The programme was successful in teaching the participant to use a portable AAC device to make requests during the clinical trial and then in two home-based activities. CONCLUSION: An initial clinical trial with follow-up support for parents may be an efficient method for beginning AAC intervention and transferring the training procedures to the home setting.

Autistic Disorder↗
PubMedDate not supplied

An optic micro-switch for an eyelid response to foster environmental control in children with minimal motor behaviour.

This study assessed whether two children (11.9- and 9.7-years-old) with profound multiple disabilities and minimal motor behaviour could learn to control environmental stimulation using an eyelid response with a newly developed micro-switch. The response consisted of raising the eyelid markedly (i.e. by looking upward or opening the eyes widely). The micro-switch developed for this target response consisted of an electronically regulated optic sensor mounted on an eyeglasses' frame. Data showed that the children learned the target eyelid response to activate the micro-switch and to increase their level of environmental stimulation. Responding was largely maintained at a 2-month post-intervention check. These results indicate that continued work in this area has positive implications for the rehabilitation of children with most serious disabilities.

Child↗