Fernandez, L. 1, 2, 3 , Hoehle, B. 2 , Brock, J. 3 & Nickels, L. 3
1 University of Kaiserslautern
2 University of Potsdam
3 Macquarie University
The load that performing a task imposes is called cognitive load[1]. Pupil change is a non-neural proxy of cognitive load[2] and the neurotransmitter noradrenaline (essential for working memory[3,4]) correlates with pupil change[5].
In the current study we investigated the processing of ambiguous/unambiguous German canonical (SVO) and non-canonical (OVS) constructions using pupillometry. Unambiguously marked OVS constructions cause disruption in brain activity in the form of a Left Anterior Negativity (LAN). Some argue this indicates additional working memory costs[6,7] while others argue this indicates a local syntactic violation of canonicity[8]. Given that pupillometry is a measure of cognitive load and does not seem to reflect syntactic violations[9], we aimed to tease apart these two competing accounts which were difficult to disentangle using ERP. Additionally, we aimed to confirm pupillometry as an effective tool to measure word order processing.
We found no differences in pupil response at the first noun phrase regardless of word order. Suggesting that previous ERP differences between OVS and SVO sentences are better explained in terms of a violation of canonicity (as opposed to working memory). At the disambiguating 2nd NP and across the whole sentence, pupillometry accurately reflected the difficulties associated with different word orders.