Parsing Trimorphemic Words in Context: Evidence from Aphasia

EasyChair Preprint 6670

Abstract

Introduction. The computation of morphologically complex hierarchical structures relies on the selectional restrictions of roots and affixes. In the case of a trimorphemic word like unsinkable the prefix un- can only attach to the adjective sinkable and not to the verb sink. On the other hand, unlockable can be represented by two distinct morphological structures: [un[lockable]] (“not able to be locked”) or [[unlock]able] (“able to be unlocked”). Thus, the correct parsing of these trimorphemic words directly determines the derived meaning. We investigated morphological parsing in individuals with aphasia aiming to understand (a) whether there is a default parsing strategy, (b) how sentential-semantic context influences parsing preferences, and (c) the breakdown of morpho-semantic processing across different clinical groups of aphasia. Methods. Participants were 12 individuals with aphasia (3 fluent [FL], 2 mixed [MX], 2 mixed but predominantly non-fluent [MN], 5 non-fluent [NF]). Their task was to rate how good each sentence was and then parse a target word, which was always a word from the sentence presented below the rating scale. Results. Correct parsing was analyzed by items considering word type (right-branching ambiguous, left-branching ambiguous, right-branching unambiguous, left-branching unambiguous) and group (controls, FL, MX, MN, NF), with repeated measures on the second factor. Results showed no significant main effect of group. However, both the MX and the NF groups differed significantly from the control group across most word types. Conclusions. The results suggest that the right-branching parse is preferred early in morphological analysis. Notably, the NF group shows the inverse effect, indicating that the morphological parser can be affected in non-fluent aphasia.

Keyphrases: Prefix Stripping, aphasia, context effects, morphological parsing

@booklet{EasyChair:6670,
  author    = {Kyan Salehi and Caitlyn Antal and Alexa R. Falcone and Laura Pissani and Roberto G. de Almeida},
  title     = {Parsing Trimorphemic Words in Context: Evidence from Aphasia},
  howpublished = {EasyChair Preprint 6670},
  year      = {EasyChair, 2021}}