Meet our Psychologists
Licensed. Expert neurodiversity-affirming evaluations. Here to give you answers.
Every evaluation at Grey Matter is conducted or directly supervised by a licensed doctoral-level psychologist. We don't outsource interpretation.
Dr. Quincee Gideon
Dr. Gideon is the founder and owner of Grey Matter Psychological Assessment and the primary evaluating psychologist for ADHD, autism, and learning disorder assessments. She created Grey Matter to fill a gap she saw clearly: people who suspected they were neurodivergent struggling to access evaluations that were thorough, affirming, and actually useful in their real lives.
Her clinical focus is on comprehensive neurodiversity-affirming evaluations for children, adolescents, and adults — with particular expertise in ADHD across the lifespan, autism spectrum disorder in adults (including those who masked for years before seeking answers), and learning disorders such as dyslexia and executive functioning differences.
In addition to her assessment work, Dr. Gideon has received extensive training in forensic psychological evaluation — a background that informs the precision and rigor she applies to every report she writes. She evaluates clients in person at Grey Matter's Santa Monica offices and virtually throughout California.
Specialties
- ✓ADHD evaluation across the lifespan (children, teens, adults)
- ✓Autism spectrum disorder assessment, including late-identified adults
- ✓ADHD and autism in women and girls
- ✓Learning disorder testing (dyslexia, dyscalculia, dysgraphia)
- ✓Exam accommodations documentation (SAT, ACT, GRE, LSAT, MCAT, Bar Exam)
- ✓Forensic psychological evaluation
Dr. Megan Johnson
Dr. Johnson is the supervising psychologist at Grey Matter Psychological Assessment, where she oversees the practice's clinical standards and brings deep expertise in both forensic and neuropsychological evaluation. She is the psychologist clients work with for complex cognitive assessments, neurological conditions, and evaluations connected to legal proceedings.
Her forensic training is extensive and field-tested. Dr. Johnson completed significant forensic work at Twin Towers Correctional Facility in downtown Los Angeles — the largest mental health facility of its kind in the world — where she evaluated individuals for competency to stand trial, criminal responsibility, and fitness for duty.
Alongside her forensic background, Dr. Johnson specializes in neuropsychological evaluation — assessing and diagnosing conditions such as dementia, traumatic brain injury (TBI), and other cognitive impairments. At Grey Matter, she also conducts ADHD assessments and diagnostic evaluations, and plays a central role in maintaining the clinical excellence that defines every report the practice produces.
Specialties
- ✓Forensic psychological evaluation
- ✓Competency to stand trial evaluations
- ✓Criminal responsibility (insanity) evaluations
- ✓Fitness for duty evaluations
- ✓Neuropsychological assessment (dementia, TBI, cognitive impairment)
- ✓ADHD evaluation (mini and comprehensive)
- ✓Conservatorship and capacity evaluations
What Does Neurodiversity-Affirming Actually Mean?
What does "neurodiversity-affirming" mean at Grey Matter?
It means we start from the position that ADHD, autism, and other forms of neurodivergence are natural variations in how a brain works, not deficits to be corrected. A neurodiversity-affirming evaluation still uses rigorous, standardized testing — the science doesn't change — but the framing does. You leave with a clear picture of how your brain works, written in language that treats that picture as useful information about you, not a list of what's wrong with you.
Do I work directly with a licensed psychologist, or with a trainee?
Every evaluation at Grey Matter is conducted or directly supervised by a licensed doctoral-level psychologist — Dr. Gideon or Dr. Johnson. We don't outsource interpretation, testing administration, or report writing to unsupervised trainees.
Can I request a specific psychologist for my evaluation?
Yes! You can request a specific psychologist and we'll make every effort to honor your request.
Every evaluation at Grey Matter is conducted by a licensed doctoral-level psychologist — not a technician, not an algorithm. We write every report ourselves, we deliver every feedback session personally, and we stand behind every conclusion we put on paper.
We are a small practice by design. That means you will always know who is evaluating you, you will always have direct access to your psychologist, and your report will never be a templated document with your name swapped in.
Our commitment to every client
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