Related Experiment Video
Updated: Jul 14, 2026

Assessing Dyslexia at Six Year of Age
Published on: May 1, 2020
Mental rotation of letters and shapes in developmental dyslexia
Patrycja Rusiak1, Thomas Lachmann, Piotr Jaskowski
1Department of Psychophysiology, Kazimierz Wielki University, PL 85-837 Bydgoszcz, Poland.
Abstract:
Extending the work of Corballis et al (1985, Cortex 21 225-236), we investigated mental rotation of letters (experiment 1), and of letters and shapes (experiment 2) in normal readers and developmental dyslexics. Whereas the overall response times were equal for shapes in both groups, for letters they were slower in dyslexics. For letters as well as for shapes, however, the same mental-rotation effects were obtained between the groups. The results are interpreted as support for the notion of developmental dyslexia as a deficit in functional coordination between graphemic and phonological letter representations.
Related Concept Videos
Learning Disabilities
Dyslexia
Dyslexia is a...
Visual Agnosia
Language and Cognition
Lateralization
Prosopagnosia
Higher Mental Functions of the Brain: Language
Language formation and comprehension take place in the dominant hemisphere. The dominant hemisphere is responsible for understanding the meaning of spoken, written, or sign language, as well as the ability to communicate. For most people, the left hemisphere is the dominant one. The right hemisphere, then, gives tone and emotional context to the...

