Some researchers, including Harvard neuropsychologist Gail Grodzinsky, have identified subtypes of nonverbal learning disorders.
proposes three major subtypes of nonverbal learning disorders: Prodominant Deficiency in Visual Processing Speed and Organization; Predominant Deficiency in Spatial Visualization; and Predominant Deficiency in Social Perception.
The second subtype of nonverbal learning disorders delineated by Dr. Grodzinsky
primarily involves trouble with spatial reasoning.
In neuropsychological testing, they perform poorly on visuospatial tests like Object Assembly and Block Design, and often have difficulty interrelating various information into a meaningful whole.
Motor difficulties are often also present, creating difficulties with handwriting, sports and other gross motor skill tasks, and difficulty with mathematical and time-related concepts.
Spatial orientation and awareness of the body's location in space is also below average, causing general "clumsiness".
In terms of working memory skills, Dr. Grodzinsky
has also found that people with nonverbal learning disorders affecting spatial visualization are easily "overloaded" by visuospatial information.
They sometimes struggle with reading comprehension tasks, such as summarizing a story, and can also be socially naïve.
#3: Predominant Deficiency in Social Perception
The third subtype of nonverbal learning disorders outlined by Dr. Grodzinsky
is characterized primarily by difficulties interpreting social signals.