Peter Lindsay

Effects of event rate and display time on sustained attention in hyperactive, normal, and control children

Two experiments were conducted to determine whether hyperactive boys have a unique deficit in sustained attention. Groups with DSM-III diagnoses of attention deficit disorder (ADDH), conduct disorder (CD), ADDH+CD, and learning disorder were compared with normal controls on the Continuous Performance Task. In Experiment 1, stimulus presentation rate (stimulus onset asynchrony, SOA) and display time were varied to manipulate attentional demand, and speed and accuracy of performance were measured. The ADDH group was uniquely affected, with less accurate performance at the fastest and slowest SOA. To distinguish the effects of time on task and SOA, the duration of each SOA condition was held constant in Experiment 2. The poorer performance of the ADDH group at the fastest SOA was no longer evident. This finding indicates that the deficit of sustained attention in boys who have ADDH is associated with a greater susceptibility to refractory effects, which is influenced by practice.

Mild traumatic brain injury from motor vehicle accidents: Factors associated with return to work

OBJECTIVES To describe return to work (RTW) for motor vehicle accident (MVA) survivors with mild traumatic brain injury (MTBI) and to examine relationships between RTW and injury severity, cognitive impairment, social interaction, discharge disposition, and sociodemographics. DESIGN Inception cohort assessed within 1 month of injury and at follow-up 6 to 9 months (mean = 7.4) after injury, for comparisons on outcome of RTW. SETTING Tertiary care center in Toronto (time 1); at home for follow-up. PARTICIPANTS Fifty patients with MTBI resulting from MVA who were consecutively admitted during a 20-month period ending April 1994. Thirteen of 63 eligible patients refused consent or were lost to follow-up. Mean age was 31; 62% were men. ELIGIBILITY CRITERIA (1) patients had been working; (2) they had no history of head injury, neurologic disease, or psychiatric illness requiring hospitalization; and (3) they had no catastrophic impairment from accident. MAIN OUTCOME MEASURE Return to work (at premorbid or modified level). RESULTS Of the 42% who returned to work, 12% resumed their premorbid level of employment and 30% returned to modified work. There were significant differences (p<.05) between the groups in level of social interaction, premorbid occupation, and discharge disposition. On one test of cognitive functioning the difference was at p = .06. CONCLUSION Social interaction, jobs with greater decision-making latitude, and discharge home were positively related to RTW for this population. Cognitive impairment within the first month was not a reliable indicator of RTW potential.

Cognitive science and augmentative and alternative communication

To date, research and clinical attention in the field of augmentativeand alternative communication (AAC) has largely ignored the role of cognition. This paper explores some of the theoretical issues currently being addressed in the field of cognitive science and discusses the potential impact of these issues for persons who use AAC systems. Issues considered include the information-processing capabilities of human memory systems, the limitations of working memory, the knowledge structures of long-term memory, the encoding of information into memory, the retrieval of information from memory stores, the construction of mental models to make sense of the world, the role of metacognition in problem solving, and the nature of novice and expert performances. Case examples from the AAC field are used to illustrate how the theoretical constructs presented may apply to system design and to clinical and educational practice. Directions for further research to address the information processing issues in the AAC fie...

Effects of Early Intervention on Hearing Impaired Children

A longitudinal study was conducted of 118 children with severe and profound hearing losses-Children were first tested when they were between 3 and 5 years and again in 3 or 4 years, using measures of receptive and expressive spoken language, receptive language in the childs primary educational modality, receptive and expressive mother-child communication, and social development. A multivariate design was used to investigate the effects of age of intervention, program intensity, and parent instruction on the childrens linguistic and social development. Early intervention was associated with higher receptive language scores in the first, but not in the final year. Age of intervention was not related to any other language measure or the measure of social development. Consistent effects were not associated with program intensity or parent instruction.

Social inclusion of employees who are blind or low vision

This study investigated social integration in the workplace of 13 blind or low vision employees. Qualitative research methodology was used. The employees participated in semi‐structured interviews responding to questions on social barriers in the workplace. The findings show that they do not enjoy full integration into the workplace because of the lack of social support. Social barriers are not acknowledged as workplace barriers that lead to social exclusion at work. Organizations need to be proactive in developing concrete solutions to remove social barriers and facilitate the social inclusion of blind or low‐vision employees into the workplace.

Including people with disabilities in research: implications for the field of augmentative and alternative communication

This paper presents a collaborative, investigative approach that incorporates the perspectives of people with disabilities into the design of research studies. The approach integrates elements of participatory and action research methodologies within a framework of an explicit, negotiated partnership. Three scenarios involving people who use augmentative and alternative communication are provided and theoretical, methodological, and ethical issues are outlined. It is proposed that fostering a research partnership among people with disabilities, service providers, and researchers not only assists in meeting research goals but furthers transformative action on a personal, community, and societal level.

Approaching literacy with AAC graphics

This paper examines the possible impact on beginning reading of graphic representational system (GRS) instruction and usage during the emergent literacy years of young children with severe speech and physical impairments (SSPI). The unique development of children who use GRS symbols for communication is discussed within the context of the research literature on the reading process, visual processing, graphic representational processing, and language development. The position taken argues that one should remain open to the possibility of a differential impact upon beginning reading due to use of different types of GRSs. The objectives of this paper are to refine the questions relating to the relationship between the use of a GRS during the preschool years and the childs ultimate reading acquisition.

Factors Affecting the Placement of Preschool-Aged Deaf Children

The placement in and movement among preschool programs of 131 children with severe and profound hearing losses was monitored over four years. Longitudinal data were obtained on the childrens linguistic and social development.In the first year of the study, most of the children were enrolled in auditory/oral (A/O) programs. By the final year, most were enrolled instead in total communication (TQ programs; similar movement occurred from individual to classroom programs. Children in A/O individual programs had the most hearing, highest intelligence and most favorable family profile, followed by children in A/O classes, TC individual programs, and TC classes. Scores on measures of spoken language followed the same pattern. On measures of receptive language and mother-child communication, children in A/O individual programs and those in TC classes had similar scores. Children in TC individual programs came next, and last were children in A/O classes. These findings have implications for the choice of programs for preschool deaf children.

Database for the identification of AAC users for participation in research, product development, and service delivery

A nonprofit, self-sustaining database that contains the names of individuals, age 16 or over, with cerebral palsy who do not speak or are unable to speak successfully in at least some situations that are important to them has been established. The database is available on a cost basis to researchers, market researchers, and leaders of disability advocacy groups. Persons with disabilities operate the DIREL™ database.