Neurolinguistic & psycholinguistic investigations on evidentiality in Turkish

 
 
 
 
 
 
 

---

 
 
 
Neurolinguistic aspects of 
evidentiality: 
studies on agrammatic 
aphasia
 
 
 
 
 
 
 
 
 
 
 
 
 
 

---

23 
 
 
 
 
 
 
 
CHAPTER 2 
2.
 
Finite verb inflections for 
evidential categories and 
source identification in Turkish 
agrammatic Broca’s aphasia
14
 
14
This chapter is adapted from Arslan, S., Aksu-Koç, A., Maviş, I., & Bastiaanse, 
R. (2014). Finite verb inflections for evidential categories and source identification 
in Turkish agrammatic Broca’s aphasia. 
Journal of Pragmatics, 70
, 165-181.

---

24 
Abstract:
This study presents the pioneering data on the neurological 
representation of grammatically marked evidentials with regard to their 
dissolution in agrammatic Broca’s aphasia. Across two tasks, we 
investigated the production of finite verb inflections for evidential 
categories and identification of the information sources these evidential 
categories are mapped on in Turkish individuals with agrammatic aphasia. 
In Turkish, information source is grammatically marked for three different 
past contexts: direct perception, reportative, and inferential. The following 
research questions were explored: (1) is inflection for different evidential 
categories equally affected in Turkish agrammatic aphasia? (2) Is 
identifying the categories of information source impaired? Turkish 
agrammatic speakers and non-brain-damaged speakers (NBDs) were tested 
with a production and a source identification tasks. Our findings 
demonstrate that in Turkish agrammatic speakers the direct perception 
evidential was more affected in production than the inferential and 
reportative evidentials. However, the agrammatic speakers retained the 
ability to identify the source for the direct perception. We argue that 
information source values conveyed by evidential forms are impaired in 
agrammatic aphasia. These findings are discussed on the basis of earlier 
studies to time reference and tense in agrammatism.