Measuring dysgraphia: a graded-difficulty spelling test

Area of Science:

• Neuroscience
• Cognitive Psychology
• Linguistics

Background:

• Assessing spelling ability is crucial for understanding language processing.
• Existing spelling tests may lack graded difficulty or specific validation for neurological conditions.

Purpose of the Study:

• To construct and validate a graded-difficulty spelling test (GDST) for adults.
• To investigate the relationship between spelling, language skills, and brain lateralization.
• To identify specific spelling impairments, such as selective dysgraphia.

Main Methods:

• Development of a 30-word, two-form graded-difficulty spelling test (GDST).
• Administration of GDST and background verbal/non-verbal tests to 100 healthy controls.
• Validation of GDST in patient groups with left (n=26) and right (n=20) hemisphere lesions.

Main Results:

• GDST Forms A and B showed high correlation (0.92).
• Spelling correlated strongly with reading (0.75-0.77) and moderately with vocabulary (0.57) and naming (0.39-0.40).
• Spelling ability was lateralized to the left hemisphere, with 65% of left-lesion patients in the lower quartile. Selective dysgraphia was identified in 8% of left-lesion patients.

Conclusions:

• The GDST is a reliable tool for assessing adult spelling.
• Spelling is predominantly a left-hemisphere function, closely tied to other language abilities.
• The findings support the classification of selective dysgraphia and suggest diverse neurological underpinnings for spelling disorders.