Analyzing processing effort during sentence comprehension in quiet and in noise: Evidence from eye-fixations and pupil size

Eye - fixations can be used to investigate sentence processing and the required effort during sentence comprehension. Wendt and colleagues (Wendt et al., 2014 ) proposed an eye - tracking paradigm to detect time - consuming aspects during sentence processing . P articipant s ’ eye - fixations were recorded within an audio - visual paradigm to investigate the speed of processing sentences with varying syntactic complexity . Even at high speech intelligibility level , a reduced processing speed was measured indicating increased processing effort for complex sentences . Another measure of cognitive processing effort is served by task - evoked pupillary response. For instance, Piqua rdo et al . (2010) show ed significa nt larger pupil sizes during speech comprehension for syntactically more complex object - relative sentences than for the syntactically less co mplex subject - relative sentence structures . Here, we compare both methods, i.e. p rocessing speed and pupil size , as indicator s for the required effort when processing sentences that differ in their level of syntactic complexity . Furthermore, an interaction of background noise and syntactic complexity is exanimated by analyzing processing effort for sentence s presented in quiet and in noise. Moreover, it is investigated whether both measure s provide similar or complementary information about sentence processing and the required effort.