| Popis: |
The fundamental question of language acquisition has intrigued humanity since the beginning of recorded history. One of the earliest testaments to this has been left by Greek historian Herodotus, who described a legendary experiment conducted by the Egyptian Pharaoh Psammetichus (664-610 BC) on two newborn babies which were deprived of verbal contact in hope that they will develop their own, “primordial” language. In modern times, the acquisition of vocabulary has been studied in great detail, but surprisingly little attention has been paid to acquisition of more complex language comprehension abilities. In this study we assess 14 language comprehension abilities in 31,845 autistic individuals using parent-generated reports. Unsupervised hierarchical clustering identified three distinct language comprehension phenotypes: 1) individuals in the command language phenotype were limited to comprehension of their name and simple commands (40% participants); 2) individuals in the modifier language phenotype showed additional comprehension of color, size, and number modifiers (43%); and 3) individuals in the most-advanced prepositional language phenotype added comprehension of spatial prepositions, verb tenses, flexible syntax, possessive pronouns, and fairytales (17%). The three language comprehension phenotypes likely correspond to three distinct neurological mechanisms. Elucidation of these neurological mechanisms is important not only for developing better treatment options for individuals with language deficits, but also for understanding of language evolution in archaic humans, who may have acquired language comprehension in a similar three-step-wise fashion. |
