Biomedical subjects

Murray J Dyck

Publications and source records attributed to Murray J Dyck.

9 recordsLinked to original sources

PubMed2006

Can autism, language and coordination disorders be differentiated based on ability profiles?

Children with autistic disorder (AD), mixed receptive-expressive language disorder (RELD), or developmental coordination disorder (DCD) have impairments in common. We assess which abilities differentiate the disorders. Children aged 3-13 years diagnosed with AD (n = 30), RELD (n = 30), or DCD (n = 22) were tested on measures of language, intelligence, social cognition, motor coordination, and executive functioning. Results indicate that the AD and DCD groups have poorer fine and gross motor coordination and better response inhibition than the RELD group. The AD and DCD groups differ in fine and gross motor coordination, emotion understanding, and theory of mind scores (AD always lower), but discriminant function analysis yielded a non-significant function and more classification errors for these groups. In terms of ability scores, the AD and DCD groups appear to differ more in severity than in kind.

Adolescent↗

PubMed2006

Are abilities abnormally interdependent in children with autism?

We propose that stronger than usual correlations between abilities indicate which cognitive processes are impaired in autism. Study 1 compared partial correlations (controlling age) between intelligence and social cognition in children with autism (n = 18), mental retardation (MR; n = 34), or no psychological disorder (n = 37). Correlations were stronger in the autism group. Study 2 compared correlations between measures of perceptual organization and verbal comprehension, receptive and expressive language, fine and gross motor coordination, and theory of mind, emotion recognition, and emotion understanding abilities in children with autism (n = 30) or MR (n = 24) and in a large representative sample of children (n = 449). Results indicate that autism is marked by stronger correlations between all ability domains, and MR is marked by stronger correlations between motor coordination tasks and other ability measures.

Affect↗

PubMed2005

Motor coordination, empathy, and social behaviour in school-aged children.

Children with motor coordination problems are known to have emotional difficulties and poor social skills. The current study investigated whether children with poor motor ability have poor emotion recognition skills, and whether these could be linked to problems in social behaviour. It was hypothesized that difficulties in empathic ability might be related to the poor visuo-spatial processing ability identified in children with developmental coordination disorder (as defined by the American Psychiatric Association). The relationship between motor coordination, emotion recognition, and social behaviour was examined in a sample of 234 children (113 males, 121 females; mean age 9y 7mo, [SD 1y 8mo] age range 6y 8mo to 12y 11mo). From this sample two groups of 39 children each (17 females, 22 males), one group with motor difficulties (mean age 9y 11mo [SD 2y], range 6y 11mo to 12y 11mo) and the other of control children (mean age 10y [SD ly 11mo], range 6y 11mo to 12y 11mo), matched for age and sex, were compared using a set of six emotion recognition scales that measured both verbal and perceptual aspects of empathic ability. Children with motor difficulties were found to perform more poorly on scales measuring the ability to recognize static and changing facial expressions of emotion. This difference remained even when visuo-spatial processing was controlled. When controlling for emotion recognition and visuo-spatial organization, a child's motor ability remained a significant predictor of social behaviour.

Adolescent↗

PubMed2004

The relationship between motor coordination, executive functioning and attention in school aged children.

Given the high level of comorbidity of attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD), deficits in executive function (EF), shown to be present in children with ADHD, may also be implicated in the motor coordination deficits of children with DCD. The aim of this study was to explore the relationship between EF and motor ability. A sample of 238 children, 121 girls and 117 boys, aged between 6 and 15 years was recruited for this project. Motor ability was assessed using the McCarron Assessment of Neuromuscular Development (MAND), level of inattention using the Child Behavior Checklist (CBCL), and Verbal IQ (VIQ) was estimated using subtests of the WISC-III. A reaction time task and three EF tasks measuring response inhibition, working memory and the ability to plan and respond to goal-directed tasks were administered. It was found that motor ability significantly accounted for variance in tasks measuring speed of performance, whereas inattention appeared to influence performance variability. Despite past evidence linking poor motor ability with inattention, there was little overlap in the processes that are affected in children with motor coordination or attention problems.

Adolescent↗

PubMed2004

The experience of mental death: the core feature of complex posttraumatic stress disorder.

Exposure to extreme interpersonal stress, exemplified by the experience of torture, represents a threat to the psychological integrity of the victim. The experience is likely to result in mental death, in the loss of the victim's pretrauma identity. Mental death is characterized by loss of core beliefs and values, distrust, and alienation from others, shame and guilt, and a sense of being permanently damaged. Mental death is a primary feature of a distinct posttrauma syndrome, complex posttraumatic stress disorder (PTSD), which is refractory to standard exposure therapies. We identify cognitive mechanisms that mediate the symptoms of complex PTSD, and suggest how current treatments need to be modified to obtain enhanced treatment outcomes.

Cognition↗

PubMed2004

Sensory-motor deficits in children with developmental coordination disorder, attention deficit hyperactivity disorder and autistic disorder.

Children who have been diagnosed with any one developmental disorder are very likely to meet diagnostic criteria for some other developmental disorder. Although comorbidity has long been acknowledged in childhood disorders, little is understood about the mechanisms that are responsible for the high level of comorbidity. In a series of studies, we have investigated the link between sensory-motor deficits and developmental disorders. Poor sensory-motor integration has long been implicated as a cause of motor problems in developmental disorders such as developmental coordination disorder (DCD), and our recent research has also investigated sensory-motor deficits in children with attention deficit hyperactivity disorder (ADHD) and autistic disorder. Based on a critical examination of relevant literature and some of our recent research findings, we argue that the importance of poor sensory-motor functioning in discriminating children with different disorders has been underestimated. Poor sensory-motor coordination appears to be linked to DCD, but not ADHD. Also, sensory-motor deficits in children with DCD and autistic disorder may provide insight into some of the social difficulties found in these groups of children. This research will increase our understanding of why children with one developmental disorder typically also have problems in other areas.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

Emotion recognition/understanding ability in hearing or vision-impaired children: do sounds, sights, or words make the difference?

BACKGROUND: This study was designed to assess whether children with a sensory disability have consistent delays in acquiring emotion recognition and emotion understanding abilities. METHOD: Younger (6-11 years) and older (12-18 years) hearing-impaired children (HI; n = 49), vision-impaired children (VI; n = 42), and children with no sensory impairment (NSI; n = 72) were assessed with the Emotion Recognition Scales (ERS), which include two tests of the ability to recognize vocal expressions of emotion, two tests of the ability to recognize facial expressions of emotion, and three tests of emotion understanding. RESULTS: Results indicate that when compared with age-peers, HI children and adolescents have significant delays or deficits on all ERS, but VI children and adolescents are delayed only on emotion recognition tasks. When compared with children group-matched for verbal ability (Wechsler verbal scales), the achievement of HI children on ERS equals or exceeds that of controls; VI children underachieve on an emotion recognition task and overachieve on an emotion vocabulary task compared to verbal ability matched peers. CONCLUSIONS: We conclude that VI children have a specific emotion recognition deficit, but among HI children, performance on emotion recognition and emotion understanding tasks reflects delayed acquisition of a broad range of language-mediated abilities.

Adolescent↗

PubMed2004

Is the discrepancy criterion for defining developmental disorders valid?

BACKGROUND: Most developmental disorders are defined by an achievement discrepancy in which achievement on one or more specific abilities is substantially less than a person's measured intelligence. We evaluated the validity of this discrepancy criterion by assessing parameters that determine variability across abilities and by assessing relationships between achievement discrepancies and behavioral disturbances. METHODS: Measures of intelligence, language, motor coordination, empathic ability, and attentional control were administered to a representative sample of 390 children aged 3 to 12 years. Parent ratings of child behavior were obtained. RESULTS: Results indicate that achievement discrepancies are a function of the correlation between ability measures, the shape of the ability distributions, and position on an index ability dimension. Discrepancies in achievement were not related to behavioral disturbance, but underachievement relative to age peers was invariably related to behavioral disturbance. CONCLUSIONS: We conclude that developmental disorders need to be redefined in ways that are consistent with how Mental Retardation is now defined, by (a) underachievements, (b) of defined magnitude, (c) using standardized measures, (d) with known relations to normal development, and (e) concurrent deficits on standardized measures of impaired function.

Age Factors↗

PubMed2003

Can the Emotion Recognition Ability of Deaf Children be Enhanced? A Pilot Study.

We evaluated the effectiveness of an 11-lesson psychoeducational program designed to enhance the ability of deaf children to understand the emotional experience of themselves and other people. The "Funny Faces Program" was provided to 14 children, aged 9 to 13, with moderate to profound hearing impairments. All children were enrolled in an "oral" education program at a school for the deaf. Alternate forms of the Emotion Recognition Scales (Dyck, Ferguson, & Shochet, 2001) were administered at pretest and posttest. Results indicate significant increases in emotion vocabulary and emotion comprehension but not in the speed or accuracy of emotion recognition (ER), from pretest to posttest. At posttest, children whose hearing loss was moderate to severe did not differ from hearing children in ER abilities but children with profound hearing loss continued to show substantial ability deficits.

Journal Article↗