Analogous development of local/global preference in vision and touch.

Several studies have investigated local/global perception in vision, but less attention has been given to touch. To get better insights into the mechanisms of local/global perception, we here explore its developmental path and compare performance across vision and touch. Particularly, we focus on the impact of element size and density on local/global perception. Forty-four typically developing individuals covering an age-range from 6.01 to 26.48 years completed a similarity judgment task in vison and touch. The 3D printed stimuli were made out of local elements (squares or triangles) that were arranged to form a global shape (square or triangle). Local and global shape could either be consistent or inconsistent. The local elements of the stimuli had three possible sizes (3.5, 5.3 or 9 mm) while the size of the global shape ranged from 1.99 to 3.35 cm. In the critical test trials, participants had to say whether the inconsistent target stimulus was more similar to either the consistent square or the consistent triangle. Responses were categorized as “global” when the chosen stimulus had the same global configuration as the target and “local” otherwise. Results showed that the proportion of global responses increased with age in both vision and touch. For stimuli with large local elements, however, there was no global preference across all ages in touch. Importantly, the correlation between vision and touch of the proportion of global responses increased with age. These findings indicate that the coordination between vision and touch for local/global perception develops with age. This might indicate that they share the same or similar mechanisms developing with age.