Causality, subjectivity and mental spaces: Insights from on-line discourse processing

Abstract Research has shown that it requires less time to process information that is part of an objective causal relation describing states of affairs in the world (She was out of breath because she was running), than information that is part of a subjective relation (She must have been in a hurry because she was running) expressing a claim or conclusion and a supporting argument. Representing subjectivity seems to require extra cognitive operations. In Mental Spaces Theory (MST; Fauconnier, Gilles. 1994. Mental spaces: Aspects of meaning construction in natural language. Cambridge: MIT Press) the difference between these two relation types can be described in terms of an extra mental space in the discourse representation of subjective relations: representing the Subject of Consciousness (SoC). In processing terms, this might imply that the processing difference is not present if this SoC has already been established in the discourse. We tested this prediction in two eye tracking experiments. The results of Experiment 1 showed that signaling the subjectivity of the relation by introducing a subject of consciousness beforehand did not diminish the processing asymmetry compared to a neutral context. However, the relative complexity of subjective relations was diminished in the context of Free Indirect Speech (No! He was absolutely sure. There was no doubt about it. She was running so she was in hurry; Experiment 2). In terms of MST and the representation of subjectivity in general, this implies that not only creating a representation of a thinking subject, but also assigning a claim to this thinking subject requires extra processing effort.