Reversing expectations during discourse comprehension

Abstract

In two ERP experiments, we asked whether comprehenders used the concessive connective, even so, to predict upcoming events. Participants read coherent and incoherent scenarios, with and without even so, e.g. "Elizabeth had a history exam on Monday. She took the test and aced/failed it. (Even so), she went home and celebrated wildly.", as they rated coherence (Experiment 1) or simply answered intermittent comprehension questions (Experiment 2). The semantic function of even so was used to reverse real-world knowledge predictions, leading to an attenuated N400 to coherent versus incoherent target words ("celebrated"). Moreover, its pragmatic communicative function enhanced predictive processing, leading to more N400 attenuation to coherent targets in scenarios with than without even so. This benefit however, did not come for free: the detection of failed event predictions triggered a later posterior positivity and/or an anterior negativity effect, and costs of maintaining alternative likelihood relations manifest as a sustained negativity effect on sentence-final words.

Keywords: Discourse processing; ERP; N400; P600; concessive connectives; event structures; late negativity; prediction.

Figure 1

Electrode montage, showing each 3-electrode region used for analysis. Regions in dark grey were part of the mid-regions omnibus ANOVA and regions in light grey were part of the peripheral regions omnibus ANOVA.

Figure 2

Grand-averaged waveforms to critical words in Experiment 1 (coherence rating task) showing effects of Coherence at electrodes Fz, Cz and Pz. Panel A: waveforms to critical words in plain coherent (black solid) and plain incoherent (red dotted) scenarios. Panel B: waveforms to critical words in even-so coherent (black solid) and even-so incoherent (red dotted) scenarios. Voltage maps show differences in ERPs between incoherent and coherent critical words (incoherent minus coherent) between 350-450ms (N400) and 600-800ms (P600).

Figure 3

Grand-averaged waveforms to critical words in Experiment 1 (coherence rating task) showing effects of Even-so at electrodes Fz, Cz and Pz. Panel A: waveforms to critical words in coherent plain (black solid) and coherent even-so (blue dotted) scenarios. Panel B: waveforms to critical words in incoherent plain (black solid) and incoherent even-so (blue dotted) scenarios. Voltage maps show differences in ERPs between even-so and plain critical words (even-so minus plain) between 350-450ms and 600-800ms.

Figure 4

Grand-averaged waveforms to sentence-final words in Experiment 1 (coherence rating task). ERPs to sentence-final words in all four conditions are shown at electrodes Fz, Cz and Pz. Plain coherent: black solid line; Plain incoherent: blue dashed line; Even-so coherent: green solid line; Even-so incoherent: red dotted line.

Figure 5

Grand-averaged waveforms to critical words in Experiment 2 (comprehension task) showing effects of Coherence at electrodes Fz, Cz and Pz. Panel A: waveforms to critical words in plain coherent (black solid) and plain incoherent (red dotted) scenarios. Panel B: waveforms to critical words in even-so coherent (black solid) and even-so incoherent (red dotted) scenarios. Voltage maps show differences in ERPs between incoherent and coherent critical words (incoherent minus coherent) between 350-450ms (N400) and 600-800ms (P600).

Figure 6

Grand-averaged waveforms to critical words in Experiment 2 (comprehension task) showing effects of Even-so at electrodes Fz, Cz and Pz. Panel A: waveforms to critical words in coherent plain (black solid) and coherent even-so (blue dotted) scenarios. Panel B: waveforms to critical words in incoherent plain (black solid) and incoherent even-so (blue dotted) scenarios. Voltage maps show differences in ERPs between even-so and plain critical words (even-so minus plain) between 350-450ms and 600-800ms.

Figure 7

Grand-averaged waveforms to sentence-final words in Experiment 2 (comprehension task). ERPs to sentence-final words in all four conditions are shown at electrodes Fz, Cz, and Pz. Plain coherent: black solid line; Plain incoherent: blue dashed line; Even-so coherent: green solid line; Even-so incoherent: red dotted line.