Spatial effects in word categorization are accounted for by un-embodied, task-related, symbolic/linguistic compatibility principles , not by perceptual simulations.

In this study, we focused on the effects of spatial features of objects to which words refer on word recognition. Specifically, we investigated the origin of the effects of the (conceptual) compatibility between the typical location of the entities denoted by written words (e.g., “up” for eagle and “down” for carpet) and either the actual position of the words on the screen (e.g., upper vs. lower part of the screen) or the response position (e.g., upper- vs. lower- key presses) in binary categorization tasks (cf., Šetić and Domijan, 2007). In two experiments we observed faster RTs when the typical position of the stimulus referent in the real world was compatible with either the stimulus (Experiment 1; N=24) or response (Experiment 2; N=12) physical position. In contrast to the predictions of the perceptual simulation account (e.g., Barsalou, 1999), these conceptual compatibility effects do not seem to depend on whether there was an overlap between simulated processes possibly triggered by the presented stimulus and sensory-motor processes actually required by the task: in Experiment 2, response keys can be represented as one above the other (i.e., one lower key and one upper key), but one key was actually closer to the participant and the other was further away. Rather, they appear to depend critically on whether the involved stimulus and/or response dimensions had binary, variable values: the stimulus-stimulus compatibility effect observed in Experiment 1 disappeared when, in a third experiment (N=24), the stimulus physical position did not vary randomly but was kept constant within each block of trials. Notably, a compatibility effect between response position and another (non-spatial) conceptual dimension of the stimulus (i.e., its semantic category) was observed in all three experiments: further (unplanned) analyses revealed faster RTs when stimuli referring to living entities were responded to with either upper or right-key presses and stimuli referring to non- living entities were responded to with either lower- or left-key presses. This effect is analogous to the so-called MARC [linguistic markedness of response codes] effect, which is usually observed in the number domain (i.e., faster right and left responses to even and odd numbers, respectively, when participants have to judge the number parity status). Both this semantic MARC-like effect and conceptual spatial compatibility effects (as well as their disappearance when one of the critical stimulus dimensions is presented in a blocked design) are accounted for by the polarity principle (Proctor & Cho, 2006), according to which these effects originate from the alignment of the polarities of either different stimulus dimensions or stimulus and response dimensions. Thus, we provide empirical evidence suggesting that conceptual spatial compatibility effects in binary word categorization tasks – i.e., one of the most renowned phenomena reported as evidence in support of the embodied theory of language processing – might be only incidentally consistent with the embodied approach. Indeed, these phenomena appear to be more properly accounted for by an alternative view, which traces them back to more general, un-embodied, strategic, task-related, mechanisms of symbolic/verbal compatibility (Treccani et al., 2019)