Samantha Chen

Colour vision in ADHD: Part 1 - Testing the retinal dopaminergic hypothesis

ObjectivesTo test the retinal dopaminergic hypothesis, which posits deficient blue color perception in ADHD, resulting from hypofunctioning CNS and retinal dopamine, to which blue cones are exquisitely sensitive. Also, purported sex differences in red color perception were explored.Methods30 young adults diagnosed with ADHD and 30 healthy young adults, matched on age and gender, performed a psychophysical task to measure blue and red color saturation and contrast discrimination ability. Visual function measures, such as the Visual Activities Questionnaire (VAQ) and Farnsworth-Munsell 100 hue test (FMT), were also administered.ResultsFemales with ADHD were less accurate in discriminating blue and red color saturation relative to controls but did not differ in contrast sensitivity. Female control participants were better at discriminating red saturation than males, but no sex difference was present within the ADHD group.ConclusionPoorer discrimination of red as well as blue color saturation in the female ADHD group may be partly attributable to a hypo-dopaminergic state in the retina, given that color perception (blue-yellow and red-green) is based on input from S-cones (short wavelength cone system) early in the visual pathway. The origin of female superiority in red perception may be rooted in sex-specific functional specialization in hunter-gather societies. The absence of this sexual dimorphism for red colour perception in ADHD females warrants further investigation.

Color vision in ADHD: Part 2 - Does Attention influence Color Perception?

BackgroundTo investigate the impact of exogenous covert attention on chromatic (blue and red) and achromatic visual perception in adults with and without Attention Deficit Hyperactivity Disorder (ADHD). Exogenous covert attention, which is a transient, automatic, stimulus-driven form of attention, is a key mechanism for selecting relevant information in visual arrays.Methods30 adults diagnosed with ADHD and 30 healthy adults, matched on age and gender, performed a psychophysical task designed to measure the effects of exogenous covert attention on perceived color saturation (blue, red) and contrast sensitivity.ResultsThe effects of exogenous covert attention on perceived blue and red saturation levels and contrast sensitivity were similar in both groups, with no differences between males and females. Specifically, exogenous covert attention enhanced the perception of blue saturation and contrast sensitivity, but it had no effect on the perception of red saturation.ConclusionThe findings suggest that exogenous covert attention is intact in adults with ADHD and does not account for the observed impairments in the perception of chromatic (blue and red) saturation.

Book Review: Psychological assessment of culturally and linguistically diverse children and adolescents

There is an increasing proportion of immigrants and refugees around the world whose children struggle to adjust to the school environment and face challenges with academic achievement. Many of these children and adolescents experience significant learning, behavioural, social, and emotional difficulties that require professional assessment and treatment services. Psychological Assessment of Culturally and Linguistically Diverse Children and Adolescents was written as a resource for school and clinical psychologists who work with children and adolescents, as well as other mental health professionals in educational or counselling psychology. The 352-page volume is divided into 10 chapters and provides an evidence-based systematic developmental framework for psychological assessment and diagnosis of children and adolescents from diverse linguistic and cultural backgrounds. The book provides practical strategies for assessment in the native language and the acquired language, integrates current research on the development of second-language learning and literacy with key issues for interpreting assessment data, and discusses the academic, language learning, and social-emotional needs of immigrant and refugee children from diverse backgrounds.

Book Review: DSM-5 diagnosis in the schools, by R. M. Tobin and A. E. House

The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association [APA], 2013) is generally viewed as a universal authority for psychiatric diagnosis in North America. It is an important classification and diagnostic tool used by mental health professionals in a variety of clinical and rehabilitative settings, including psychiatrists, psychologists, social workers, nurses, occupational and rehabilitation therapists, and counselors. The school system is becoming an important setting wherein significant DSM-5 diagnostic determinations are occurring. Moreover, schools serve as an increasingly important venue for mental health promotion and treatment for students presenting with significant psychological issues, as well as for targeted prevention for those at risk. DSM-5 Diagnosis in the Schools was written as a resource for professionals in educational and school psychology, child and adolescent clinical or counseling psychology, as well as educational administration and policy. The 268-page volume is divided into 21 chapters and provides a solid resource discussing the system and organization of the DSM-5 and how this relates to common presenting problems in children and adolescents. The book includes practical recommendations for diagnostic decision making and coding, highlights links to special education eligibility under the Individuals With Disabilities Education Improvement Act (IDEA), discusses ethical and professional issues in school-based assessment, and emphasizes the use of diagnosis as a foundation for effective intervention.