Inner Speech as a Medium of Binding Information Across Domains

Abstract

Manipulating variables of Inner Speech (IS), the phenomenon of thinking in words, has behavioural consequences in many cognitive tasks (e.g., logical reasoning). This has led to the hypothesis that IS may serve as a separate representational medium supporting cognitive functions. For example, in [1], the authors found that a verbal shadowing task interferes with adults’ ability to integrate geometric with colour information in a spatial orientation task. Since language allows to combine words irrespective of their modality (e.g., in an expression such as “right of the green wall”), language is seen as a representational medium that can be used to integrate multiple sources of information from multiple modalities (e.g., colour and geometry). In the same vein, Bemis and Pylkkänen [2], were interested in the question whether basic linguistic combinatorial processes of concepts (“the red boat”) are also utilized in non-linguistic combinatorial processes. In a visual task, participants had to match pictures that showed a combination of two conceptual features (shape and colour) to elicit combination processes across domains. The authors found higher activation in brain areas utilized in linguistic combinatorial processing in trials in which visual combinatorial activity was required. This led to the conclusion that the mechanism of linguistic combinatorial processing operates also in other domains of conceptual combination. Based on this evidence that language could serve as a medium of cross-modal information binding, an empirical project will be conducted. The hypothesis is that people who have a higher propensity to engage in IS (measured with the “Internal Verbalization” factor of the “Internal Representation Questionnaire”[3]) are also better at cross-modal information binding. To investigate this, a modified version of the visual task from [2] will be used. The participantshavetomatchobjectsthat carry two conceptual features (colour and shape), which requires cross-modal binding. The predicted outcome is that participants who engage more in IS should show a reduced reaction time in matching the correct pictures (if IS supports cross- modal binding). To see if people use verbalization as a strategy in the matching task, the stimuli will be divided into objects that are verbalizable and non-verbalizable.

References

[1] L. Hermer-Vazquez, E. S. Spelke, and A. S. Katsnelson, “Sources of Flexibility in Human Cognition: Dual-Task Studies of Space and Language,” Cogn. Psychol., vol. 39, no. 1, pp. 3–36, 1999, doi: 10.1006/cogp. 1998.0713.

[2] D. K. Bemis and L. Pylkkänen, “Combination across domains: An MEG investigation into the relationship between mathematical, pictorial, and linguistic processing,” Front. Psychol., vol. 3, no. JAN, pp. 1–20, 2013, 10.3389/fpsyg.2012.00583.

[3] H. Roebuck and G. Lupyan, “The Internal Representations Questionnaire: Measuring modes of thinking,” Behav. Res. Methods, vol. 52, no. 5, pp. 2053–2070, 2020, doi: 10.3758/s13428–020-01354-y.