L ｅａ rnin ｇ ｄ is ａ b ｉｌ ities are v ｅ ry c ｏ mmon. Th ｅ y ａ f ｆ ect perhaps １ 0 perce ｎｔ o ｆ al ｌ ch ｉ ldr ｅ n. Four times as ｍａ ny bo ｙ s as girlｓ ha ｖｅ ｌ ea ｒ ning ｄ i ｓ ab ｉ l ｉｔ ies． Since ab ｏｕ t １９ 70,n ｅｗ rese ａｒ ch h ａ s ｈ e ｌ ped brain scient ｉｓt ｓ un ｄ erst ａ nd ｔ h ｅ s ｅ pro ｂ le ｍ s b ｅ tter. Scie ｎ tist ｓ no ｗ ｋｎow there ａ re m ａｎ y di ｆｆｅｒ ent kinds of le ａ rning disa ｂ ilit ｉ es anｄ t ｈ at they are ｃ aus ｅ d b ｙ ｍ a ｎ y d ｉ fferen ｔ thi ｎｇ s． Th ｅ r ｅ is n ｏ l ｏ nge ｒ ａ n ｙ question ｔｈ at a ｌｌ learning disa ｂ ilit ｉ es ｒｅsu ｌ t from d ｉ ff ｅｒｅ n ｃ es in t ｈｅ w ａ y t ｈ e ｂｒ ain is organiz ｅ d. You c ａ nnot ｌｏ ok at a child and tell if ｈｅ or ｓ he ha ｓ a learnｉ n ｇ disabili ｔ y. The ｒ e ｉ s no ou ｔｗ ard sig ｎ of t ｈ e diso ｒ d ｅ r. Ｓ o ｓｏｍｅ res ｅ arch ｅｒ s b ｅ gan looking a ｔ the brai ｎ its ｅ lf to learn ｗ h ａ t ｍ ig ｈ t ｂ e wr ｏ ng. In o ｎｅ st ｕ dy，res ｅ ar ｃ he ｒ s exa ｍ in ｅ d ｔ he ｂｒａ in o ｆ a learnin ｇ-di ｓ abl ｅ d person,ｗ ho ｈ ad ｄｉ ed ｉ n ａｎ ａｃ cident. Ｔ heｙ foun ｄ two unusual t ｈ i ｎ g ｓ. One ｉ nvol ｖ e ｄ c ｅ l ｌｓ in ｔｈ e ｌeft side of ｔｈ e br ａｉ n，w ｈ ic ｈ cont ｒ ol langu ａ ge. Th ｅ se cells normally ａ re w ｈ ite. In t ｈ e ｌｅ arning－dis ａ bled ｐ e ｒｓ o ｎ,how ｅ v ｅr，the ｓ e c ｅｌｌ s ｗ e ｒｅ gray. T ｈｅ res ｅａｒｃ h ｅ rs a ｌ so ｆ o ｕ nd th ａ t many of th ｅ ｎ erve c ｅｌ l ｓ wer ｅ ｎ ot in a line ...
