Go ahead, read it again. Now say it out loud. Almost certainly not. But each time, the brain employed quite different neural circuits to perform each task, new brain imaging studies show. Reading comprehension depends on the ability to decode and recognize single words rapidly and accurately.
Any mental hesitation can destroy the high-speed flow on which reading depends.
The inability to identify and sound out properly the internal sounds, called phonemes, that make up words. English depends on the sounds of 44 phonemes and uses only 26 letters to encode them. Many poor readers have a hard time processing these phonological cues. The inability to make those auditory distinctions rapidly enough. Some brains may process information too slowly and may not be able to distinguish between the sounds from which words are composed.