Accessing numerical representations through finger-configurations.
Résumé
In everyday life, finger-configurations are commonly used to communicate about quantities, for example, when asking the bartender to bring “three more beers”. But how do we access numerical representations from fingers-configurations? It has been suggested that finger-configurations are automatically processed as symbols, similarly to Arabic digits.
Here we used EEG recording coupled with a Fast Periodic Visual Stimulation approach to study high-level semantic visual processing (i.e., accessing numerical representations). Participants were passively exposed to small numerosities (2-to-4) presented either through finger-configurations, Arabic digits or dots set. This technique provides a direct comparison of neural response patterns of each category of stimuli and clarify the finger-configurations status.
Results indicate that fingers-configurations and Arabic digits are automatically discriminated within the occipito-parietal cortex (as symbols), while dots were processed within the occipital cortex (as analog magnitude). Given its high sensitivity, the present method could provide an implicit neural marker suitable for clinical applications.