title: Grammatical Planning Units During Real-Time Sentence Production in Speakers With Agrammatic Aphasia and Healthy Speakers.
abstract: OBJECTIVE
  Grammatical encoding (GE) is impaired in agrammatic aphasia; however, the nature of such deficits remains unclear. We examined grammatical planning units during real-time sentence production in speakers with agrammatic aphasia and control speakers, testing two competing models of GE. We queried whether speakers with agrammatic aphasia produce sentences word by word without advanced planning or whether hierarchical syntactic structure (i.e., verb argument structure; VAS) is encoded as part of the advanced planning unit.
  
  
  METHODS
  Experiment 1 examined production of sentences with a predefined structure (i.e., "The A and the B are above the C") using eye tracking. Experiment 2 tested production of transitive and unaccusative sentences without a predefined sentence structure in a verb-priming study.
  
  
  RESULTS
  In Experiment 1, both speakers with agrammatic aphasia and young and age-matched control speakers used word-by-word strategies, selecting the first lemma (noun A) only prior to speech onset. However, in Experiment 2, unlike controls, speakers with agrammatic aphasia preplanned transitive and unaccusative sentences, encoding VAS before speech onset.
  
  
  CONCLUSIONS
  Speakers with agrammatic aphasia show incremental, word-by-word production for structurally simple sentences, requiring retrieval of multiple noun lemmas. However, when sentences involve functional (thematic to grammatical) structure building, advanced planning strategies (i.e., VAS encoding) are used. This early use of hierarchical syntactic information may provide a scaffold for impaired GE in agrammatism.
authors.forename: Jiyeon
authors.initials: J
authors.lastname: Lee
authors.forename: Masaya
authors.initials: M
authors.lastname: Yoshida
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Thompson
mesh_terms: D000375:Aging / Q000523:psychology; D001039:Aphasia, Broca / Q000209:etiology / Q000523:psychology*; D053483:Eye Movement Measurements; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D007807:Language Tests; D008037:Linguistics; D008297:Male; D008606:Mental Processes; D008875:Middle Aged; D010775:Photic Stimulation; D011581:Psychological Tests; D011932:Reading; D013060:Speech; D020521:Stroke / Q000150:complications / Q000523:psychology; D013997:Time Factors; D055815:Young Adult