Complex sentence: The Selective Attention Theory suggests that color recognition as opposed to reading a word, requires more attention, the brain needs to use more attention to recognize a color than to word encoding, so it takes a little longer.
Split into simpler sentences: The Selective Attention Theory suggests that color recognition as opposed to reading a word, requires more attention. In other words, the brain needs to use more attention to recognize a color than to word encoding, so it takes a little longer.