Structural imaging in dyslexia: the planum temporale

Area of Science:

• Neurobiology
• Cognitive Neuroscience
• Developmental Psychology

Background:

• The neurobiological basis of dyslexia has been investigated through brain imaging, with a focus on planum symmetry.
• Previous imaging studies on planum symmetry in dyslexia yielded inconsistent results, potentially due to methodological variations and insufficient control for confounding factors like handedness, sex, and cognitive abilities.

Purpose of the Study:

• To explore the functional significance of planum temporale asymmetry in relation to reading disability.
• To identify key factors that need to be controlled in future neuroimaging studies of dyslexia.

Main Methods:

• Review and synthesis of existing neuroimaging and behavioral studies on planum temporale asymmetry.
• Analysis of associations between planum asymmetry, hand preference, and verbal skills in various populations.

Main Results:

• Structural imaging studies have not definitively clarified the neurobiology of dyslexia.
• Converging evidence indicates that variations in planum temporale asymmetry possess functional significance.
• A significant association was observed between planum asymmetry, hand preference strength, and general verbal abilities (e.g., vocabulary, comprehension).

Conclusions:

• While structural imaging has not fully elucidated the neurobiology of dyslexia, planum temporale asymmetry appears functionally relevant.
• Future research should control for hand preference and general verbal ability to better understand the brain structure-language relationship in dyslexia.