042-22 – A systematic review and activation likelihood estimation meta-analysis of tactile texture processing in the brain

Humans use discriminative touch to perceive texture through dynamic interactions with surfaces, which activates low-threshold mechanoreceptors in the skin. Previous fMRI studies suggest activations in the primary (SI) and secondary (SII) somatosensory cortices, posterior parietal cortex (PPC), primary (MI) and premotor cortices, supplementary motor area (SMA), and insula for texture perception during discriminative touch. This meta-analysis aimed to collate research articles using fMRI methods, to identify regions of the brain associated with texture perception of various stimuli during discriminative touch. A coordinate-based meta-analysis (activation likelihood estimation, ALE) was performed to investigate brain areas implicated in texture discrimination when compared to control, non-haptic control (e.g. rest or visual control) and haptic control (e.g. haptic shape or orientation), the latter contrast was employed to highlight areas active due texture processing only. Thirteen studies, contributing 23 experiments (328 participants; 273 foci), were selected by systematic review. ALE analysis was performed and conjunction and contrast analyses compared processing of texture. Concordant activations were identified in the left SI, PPC, MI, and insula, in the right posterior insula and SII, and the bilateral ventral premotor cortex (PMv), and SMA for the texture > control contrast. Contrast analysis demonstrates PI and SII activations are not as prevalent as SI, MI and PPC activations after controlling for other haptic elements, suggesting preferential processing of texture in high-order structures.