title: Losing track of time? Processing of time reference inflection in agrammatic and healthy speakers of German.
abstract: BACKGROUND
  Individuals with agrammatic aphasia (IWAs) have problems with grammatical decoding of tense inflection. However, these difficulties depend on the time frame that the tense refers to. Verb morphology with reference to the past is more difficult than with reference to the non-past, because a link needs to be made to the past event in discourse, as captured in the PAst DIscourse LInking Hypothesis (PADILIH; Bastiaanse, R., Bamyaci, E., Hsu, C., Lee, J., Yarbay Duman, T., Thompson, C. K., 2011. Time reference in agrammatic aphasia: A cross-linguistic study. J. Neurolinguist. 24, 652-673). With respect to reference to the (non-discourse-linked) future, data so far indicate that IWAs experience less difficulties as compared to past time reference (Bastiaanse, R., Bamyaci, E., Hsu, C., Lee, J., Yarbay Duman, T., Thompson, C. K., 2011. Time reference in agrammatic aphasia: A cross-linguistic study. J. Neurolinguist. 24, 652-673), supporting the assumptions of the PADILIH. Previous online studies of time reference in aphasia used methods such as reaction times analysis (e.g., Faroqi-Shah, Y., Dickey, M. W., 2009. On-line processing of tense and temporality in agrammatic aphasia. Brain Lang. 108, 97-111). So far, no such study used eye-tracking, even though this technique can bring additional insights (Burchert, F., Hanne, S., Vasishth, S., 2013. Sentence comprehension disorders in aphasia: the concept of chance performance revisited. Aphasiology 27, 112-125, doi:10.1080/02687038.2012.730603).
  
  
  OBJECTIVE
  This study investigated (1) whether processing of future and past time reference inflection differs between non-brain-damaged individuals (NBDs) and IWAs, and (2) underlying mechanisms of time reference comprehension failure by IWAs.
  
  
  METHODS
  A visual-world experiment combining sentence-picture matching and eye-tracking was administered to 12 NBDs and 6 IWAs, all native speakers of German. Participants heard German sentences with periphrastic future ('will+V') or periphrastic past ('has+V-d') verb forms while they were presented with corresponding pictures on a computer screen.
  
  
  CONCLUSIONS
  NBDs scored at ceiling and significantly higher than the IWAs. IWAs had below-ceiling performance on the future condition, and both participant groups were faster to respond to the past than to the future condition. These differences are attributed to a pre-existing preference to look at a past picture, which has to be overcome. Eye movement patterns suggest that both groups interpret future time reference similarly, while IWAs show a delay relative to NBDs in interpreting past time reference inflection. The eye tracking results support the PADILIH, because processing reference to the past in discourse syntax requires additional resources and thus, is problematic and delayed for people with aphasia.
authors.affiliation: International Doctorate for Experimental Approaches to Language and Brain (IDEALAB), Universities of Groningen (NL), Newcastle (UK), Potsdam (DE), Trento (IT), & Macquarie University, Sydney (AU), PO Box 716, 9700 AS Groningen, The Netherlands; Center for Language and Cognition Groningen (CLCG), University of Groningen, PO Box 716, 9700 AS Groningen, The Netherlands; University of Potsdam, Center of Excellence Cognitive Science, Department of Linguistics, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors.forename: Laura S
authors.initials: LS
authors.lastname: Bos
authors.affiliation: University of Potsdam, Center of Excellence Cognitive Science, Department of Linguistics, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Hanne
authors.affiliation: University of Potsdam, Center of Excellence Cognitive Science, Department of Linguistics, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors.forename: Isabell
authors.initials: I
authors.lastname: Wartenburger
authors.affiliation: International Doctorate for Experimental Approaches to Language and Brain (IDEALAB), Universities of Groningen (NL), Newcastle (UK), Potsdam (DE), Trento (IT), & Macquarie University, Sydney (AU), PO Box 716, 9700 AS Groningen, The Netherlands; Center for Language and Cognition Groningen (CLCG), University of Groningen, PO Box 716, 9700 AS Groningen, The Netherlands; University Medical Center Groningen (UMCG), University of Groningen, PO Box 30001, 9700 RB Groningen, The Netherlands. Electronic address: y.r.m.bastiaanse@rug.nl.
authors.forename: Roelien
authors.initials: R
authors.lastname: Bastiaanse
mesh_terms: D000328:Adult; D000368:Aged; D001039:Aphasia, Broca / Q000503:physiopathology*; D032882:Comprehension / Q000502:physiology*; D053483:Eye Movement Measurements; D005133:Eye Movements / Q000502:physiology*; D005858:Germany; D006801:Humans; D008037:Linguistics; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*
keywords: Agrammatism; Aphasia; Discourse linking; Eye-tracking; Morphology; Spoken language comprehension; Time reference; Visual-world paradigm