ㄆ▱㻌 㻟㻱㼂㻜㻟㻟㻌 ᪥ᚰ➨ 㻣㻠㻌 ᅇ኱఍䠄㻞㻜㻝㻜䠅㻌 ࢥࢿࢡࢩࣙࢽࢫࢺ࣭ࣔࢹࣝ࡟ࡼࡿࠕ⢏ᛶ࡜㏱᫂ᛶࠖ௬ㄝࡢ᳨ド ‫ۑ‬ఀ㞟㝔╬㞝㸯࣭㏆⸨බஂ㸰࣭Taeko N. Wydell㸱 㠀఍ဨ 㸦 ᮾி㒔೺ᗣ㛗ᑑ་⒪ࢭࣥࢱ࣮ ◊✲ᡤ࣭㸰NTT ࢥ࣑ࣗࢽࢣ࣮ࢩࣙࣥ⛉Ꮫᇶ♏◊✲ᡤ࣭㸱Brunel University㸧 ࣮࣮࢟࣡ࢻ: Ⓨ㐩ᛶ dyslexia㸪 ࠕ⢏ᛶ࡜㏱᫂ᛶࠖ௬ㄝ㸪ࢥࢿࢡࢩࣙࢽࢫࢺ࣭ࣔࢹࣝ 㸯 A connectionist account of the hypothesis of granularity and transparency Mutsuo IJUIN1, Tadahisa KONDO2 and Taeko N. WYDELL3,# 1 ( Tokyo Metropolitan Institute of Gerontology, 2 NTT Communication Science Labs, 3 Brunel University) Key words: developmental dyslexia, hypothesis of granularity and transparency, connectionist model 方 法 シミュレーション 1：健常モデル  ࢿࢵࢺ࣮࣡ࢡࡢㄢ㢟ࡣ㸪௬ྡ࣭₎Ꮠ 1 ᩥᏐࡢ㡢ㄞࢆᏛ⩦ࡍ ࡿࡇ࡜࡛࠶ࡿ㸬Ꮫ⩦ᩥᏐ࡜ࡋ࡚㸪௬ྡࡣࡦࡽࡀ࡞㸪࢝ࢱ࢝ࢼ ྛ 71 ᩥᏐ㸪₎Ꮠࡣ㓄ᙜᏛᖺ 6 ᖺ௨ୗ࡛㸪ㄞࡳࡢጇᙜᛶ[2]6.5 ௨ୖࡢカㄞࡳ࡛ㄞࢇࡔ㝿࡟㸪ಁ㡢㸪ᣉ㡢ࢆྵࡲࡎ㸪ྠ୍࣮ࣔ ࣛࡢ⧞ࡾ㏉ࡋࡀ࡞࠸ 218 ᩥᏐࢆ⏝࠸ࡓ㸬ධฟຊ࡟ࡣᒁᡤ⾲⌧ ࢆ⏝࠸㸪ධຊࡣ 1 ᩥᏐࢆ 1 ࣘࢽࢵࢺ㸦ィ 360 ࣘࢽࢵࢺ㸧㸪ฟຊ ࡣ 1 ࣮ࣔࣛࢆ 1 ࣘࢽࢵࢺ㸦ィ 71 ࣘࢽࢵࢺ㸧࡛⾲⌧ࡋࡓ㸬ࢿࢵ ࢺ࣮࣡ࢡࡢᵓ㐀ࢆᅗ 㻝 ࡟♧ࡍ㸬Ꮫ⩦ᡭ⥆ࡁࡣ㸪1) 㡢ㄞࡢᏛ⩦ ࡟ඛ❧ࡕ㸪㡢㡩࠿ࡽ㡢㡩ࢆ෌ᖐィ⟬ࡉࡏࡿࡇ࡜࡟ࡼࡾᩥᏐࡢ 㡢㡩ᙧែࢆᏛ⩦ࡉࡏ㸪ḟ࡟ 2) ௬ྡ࡜₎Ꮠࡢ㡢ㄞࢆ interleaving ἲ㸦㡢ㄞᏛ⩦ヨ⾜ࡢ༙ᩘ࡟㸪ඛࡢ㡢㡩ᙧែᏛ⩦ࢆᤄධࡍࡿ㸧 ࡟ࡼࡾᏛ⩦ࡉࡏࡓ[3]㸬࡞࠾㸪₎Ꮠ࡜௬ྡ࡛ࠕ㏱᫂ᛶࠖࢆ➼ࡋ ࡃࡍࡿࡓࡵ㸪ㄞࡳ᪉ࡀ」ᩘ࠶ࡿ₎Ꮠ࡟ࡶ୍㏻ࡾࡢㄞࡳ᪉ࡋ࠿ Ꮫ⩦ࡉࡏࡎ㸦ᖹᆒ࣮ࣔࣛᩘ㸸₎Ꮠ 2㸪௬ྡ 1㸧 㸪ࡲࡓ㸪ᩥᏐ㢖 ᗘ᝟ሗࡶᏛ⩦㐣⛬࡟཯ᫎࡉࡏ࡞࠿ࡗࡓ㸬 シミュレーション 2：音韻障害モデル  㡢㡩㞀ᐖ࡟㉳ᅉࡍࡿ DD ࡢ෌⌧ࢆヨࡳࡿࡓࡵ㸪ࢩ࣑࣮ࣗࣞ ࢩࣙࣥ 1 ࡟࠾ࡅࡿ㡢㡩ᙧែᏛ⩦ࡢ⤊஢ᚋ㸪㡢㡩ィ⟬࡟㛵୚ࡍ ࡿࣘࢽࢵࢺ㸦ᅗࡢⅬ⥺㒊㸧㛫ࡢ⤖ྜ࡟ Gaussian noise ࢆ௜ຍ ࡋ࡞ࡀࡽ㸪ᩥᏐࡢㄞࡳࢆᏛ⩦ࡉࡏࡓ㸬 71 㡢㡩䝴䝙䝑䝖 20 ᩚ⌮䝴䝙䝑䝖 10 ୰㛫䝴䝙䝑䝖 360 ᩥᏐ䝴䝙䝑䝖 ᅗ 㻝㻌 䝛䝑䝖䝽䞊䜽䛾ᵓ㐀㻌 結果と考察  ᅗ 㻞㻙㼍 ࡟㡢㡩ᙧែᏛ⩦ࡢ㸪ᅗ 㻞㻙㼎㻘㼏 ࡟ࡣ୧ࣔࢹࣝ࡟࠾ࡅࡿ ᩥᏐ㡢ㄞᏛ⩦ࡢᏛ⩦᭤⥺ࢆ♧ࡍ㸬೺ᖖࣔࢹࣝ࡟࠾ࡅࡿ㡢㡩ᙧ ែᏛ⩦㸪㡢ㄞᏛ⩦ࡢ࠸ࡎࢀࡢሙྜࡶ㸪௬ྡࡼࡾ₎ᏐࡢᏛ⩦ࡀ ᪩࠿ࡗࡓ㸬ࡇࡢഴྥࡣ㡢㡩㞀ᐖࣔࢹࣝ࡟࠾ࡅࡿ㡢ㄞᏛ⩦࡛ࡶ ྠᵝ࡛࠶ࡾ㸪₎Ꮠࡢ᪉ࡀᦆയ࡟ᑐࡋ࡚ࡶẚ㍑ⓗ㡹೺࡛࠶ࡗࡓ㸬  ᮏࣔࢹ࡛ࣝ₎Ꮠ࡜௬ྡࢆ༊ูࡍࡿᒓᛶࡣ࣮ࣔࣛᩘࡢࡳ࡛࠶ ࡾ㸪࣮ࣔࣛᩘࡢከ࠸㸪ࡘࡲࡾ㡢㡩ሢࡀ኱ࡁ࠸₎Ꮠࡢᡂ⦼ࡀⰋ ࠸࡜࠸࠺ᮏ⤖ᯝࡣ㸪 ࠕ⢏ᛶ࡜㏱᫂ᛶࠖࡢ௬ㄝ࡟ྜ⮴ࡍࡿࡶࡢ࡛ ࠶ࡿ㸬ࣔࢹࣝ࡟࡜ࡗ࡚࣮ࣔࣛᩘࡀከ࠸࡜ࡣ㸪㡢㡩ᒙ࡛࢜ࣥ࡟ ࡞ࡿ࡭ࡁࣘࢽࢵࢺࡀከ࠸ࡇ࡜ࢆព࿡ࡋ㸪⤖ᯝ࡜ࡋ࡚₎Ꮠ࡛ࡣ ௚ࣘࢽࢵࢺ࠿ࡽࡢ෌ᖐᛶධຊࡢຓࡅࢆከࡃཷࡅࡿࡇ࡜ࡀ࡛ࡁ ࡿࡓࡵ[4]㸪௬ྡࡼࡾᡂ⦼ࡀⰋࡃ࡞ࡗࡓ࡜⪃࠼ࡽࢀࡿ㸬ࡓࡔࡋ㸪 ᐇᅾࡍࡿ₎Ꮠࡣ௬ྡࡼࡾࠕ㏱᫂ᛶࠖࡀపࡃ㸪ᩥᏐᙧែࡶ」㞧 ࡛࠶ࡾ㸪㡢ㄞᏛ⩦࡟ࡣ୙฼࡞Ⅼࡀከࡃ㸪ᐇ㝿ࡢ DD ฟ⌧⋡ࡶ ₎Ꮠࡢ᪉ࡀ㧗࠸㸬ࡉࡽ࡟㸪ᩥᏐ࡜ព࿡࡜ࡢ㛵㐃ᛶࡢၥ㢟ࡶṧ ࡾ㸪௒ᚋ᭦࡞ࡿ᳨ウࡀᚲせ࡛࠶ࡿ㸬 a 䝅䝭䝳䝺䞊䝅䝵䞁 1 㡢㡩ᙧែᏛ⩦ ṇ⟅⋡ 目 的  Ⓨ㐩ᛶ dyslexia㸦developmental dyslexia㸸DD㸧ࡢฟ⌧⋡ࡣ㸪 㞀ᐖࡢᐃ⩏ࡢ㐪࠸࡟ຍ࠼㸪౑⏝ゝㄒࡢ㐪࠸࡟ࡼࡾ␗࡞ࡿ㸬ྠ ࡌ࢔ࣝࣇ࢓࣋ࢵࢺㄒᅪ࡛ࡶ㸪ⱥㄒヰ⪅࡛ࡣ 10㹼12%࡛࠶ࡿࡢ ࡟ᑐࡋ㸪࢖ࢱࣜ࢔ㄒヰ⪅࡛ࡢฟ⌧⋡ࡣⱥㄒヰ⪅ࡢ༙ศ⛬ᗘ࡜ ゝࢃࢀ࡚࠾ࡾ㸪᪥ᮏㄒヰ⪅࡛ࡣ௬ྡ࡛ 1%㸪₎Ꮠ࡛ࡶ 5㹼6% ࡜࠸࠺ሗ࿌ࡀ࠶ࡿ㸬ࡇࡢฟ⌧⋡ࡢ㐪࠸࡟㛵ࡋ㸪Wydell & Butterworth ࡢࠕ⢏ᛶ࡜㏱᫂ᛶࠖ௬ㄝ[1]࡛ࡣ㸪1) 1 ᩥᏐࡀ⾲ࡍ 㡢㡩ሢࡢࢧ࢖ࢬ㸦㡢⣲ᩘ㸧ࡀ኱ࡁ࠸࡯࡝㸦⢏ᛶ㸸₎Ꮠ㸼௬ྡ 㸼࢔ࣝࣇ࢓࣋ࢵࢺ㸧㸪࠶ࡿ࠸ࡣ㸪2) ᩥᏐ㸦⥛ࡾ㸧࡜Ⓨ㡢࡜ࡢ ᑐᛂࡀつ๎ⓗ࡛࠶ࡿ࡯࡝㸦㏱᫂ᛶ㸸௬ྡ㸪࢖ࢱࣜ࢔ㄒ㸪ࢻ࢖ ࢶㄒ㸼ⱥㄒ㸼₎Ꮠ㸧 㸪ㄞࡳࡢ㞀ᐖࡀ⏕ࡌ࡟ࡃ࠸࡜ㄝ᫂ࡍࡿ㸬 ᮏㄝ࡟ᚑ࠼ࡤ㸪 ࠕ㏱᫂ᛶࠖࢆ୍ᐃ࡟ࡋࠕ⢏ᛶࠖࡢࡳࢆኚ໬ࡉ ࡏ࡚₎Ꮠ࡜௬ྡࢆẚ㍑ࡋࡓሙྜ㸪 ₎ᏐࡢᩥᏐ㡢ㄞᏛ⩦ࡣ᪩ࡃ㸪 DD ࡢⓎ⌧ᶵᗎࡢ୍ࡘ࡜ࡉࢀ࡚࠸ࡿ㡢㡩㞀ᐖ࡟ࡶ㡹೺࡛࠶ࡿ ࡇ࡜ࡀண᝿ࡉࢀࡿ㸬ࡋ࠿ࡋ㸪ࡇࡢࠕ⢏ᛶࠖ࡜ࠕ㏱᫂ᛶࠖࡢ⊂ ❧ᛶࢆே㛫ࢆᑐ㇟࡜ࡋࡓᐇ㦂ⓗ◊✲᳨࡛ドࡍࡿࡇ࡜ࡣᅔ㞴࡛ ࠶ࡿ㸬ᮏ◊✲࡛ࡣ㸪ࡇࡢၥ㢟ࢆࢥࢿࢡࢩࣙࢽࢫࢺ࣭ࣔࢹࣝ࡟ ࡼࡿࢩ࣑࣮ࣗࣞࢩࣙࣥ◊✲࡟ࡼࡾ᳨ドࡍࡿࡇ࡜ࢆ┠ⓗ࡜ࡍࡿ㸬 ࢩ࣑࣮ࣗࣞࢩࣙࣥ 1 ࡛ࡣ೺ᖖඣࡢ㡢ㄞࣔࢹࣝࢆᵓ⠏ࡋ㸪㡢㡩 Ꮫ⩦⤊஢ᚋࡢࢿࢵࢺ࣮࣡ࢡ࡟ᩥᏐࡢ㡢ㄞࢆᏛ⩦ࡉࡏࡓ㸬ࢩ࣑ ࣮ࣗࣞࢩࣙࣥ 2 ࡣ DD ඣࡢࣔࢹ࡛ࣝ࠶ࡾ㸪㡢㡩Ꮫ⩦⤊஢ᚋ࡟ 㡢㡩ィ⟬࡟ಀࡿ㒊఩ࢆᦆയࡉࡏࡓୖ࡛㸪ᩥᏐࡢ㡢ㄞࢆᏛ⩦ࡉ ࡏ㸪୧⾲グ࡟࠾ࡅࡿᏛ⩦᭤⥺ࢆẚ㍑᳨࣭ウࡋࡓ㸬 b 䝅䝭䝳䝺䞊䝅䝵䞁 1 ᩥᏐ㡢ㄞᏛ⩦ c 䝅䝭䝳䝺䞊䝅䝵䞁 2 ᩥᏐ㡢ㄞᏛ⩦ 100% 100% 100% 80% 80% 80% 60% 60% 60% 40% 40% ₎Ꮠ 20% ₎Ꮠ 20% ௬ྡ 0% ௬ྡ 0% 0 200 400 600 Epochs 800 1000 40% ₎Ꮠ ௬ྡ 20% 0% 0 300 600 900 1200 1500 Epochs 0 200 400 600 800 1000 Epochs ᅗ 㻞㻌 ྛ䝰䝕䝹䛾Ꮫ⩦᭤⥺㻌 引用文献 [1] Wydell & Butterworth (1999) Cognition, 70, 273-305. [2] ㏆⸨࣭ኳ㔝 (1999) ᪥ᮏㄒࡢㄒᙡ≉ᛶ ➨ 5 ᕳ, ୕┬ᇽ. [3] Harm & Seidenberg (1999) Psychol Rev, 106, 491-528. [4] Plaut & Shallice (1993) Cognitive Neuropsychology, 10, 377-500. ᮏ◊✲ࡣ㸪⛉Ꮫ◊✲㈝⿵ຓ㔠㸦19530672㸧ࡢຓᡂࢆཷࡅࡓ㸬◊✲ࡢᐇ᪋࡟ᙜࡓ ࡾ㸪⟃Ἴ኱Ꮫ Ᏹ㔝ᙲඛ⏕㸪୕┃ள⨾ࡉࢇ㸪㕥ᮌ㤶⳯⨾ࡉࢇࡢ༠ຊࢆᚓࡓ㸬 ̿ 752 ̿