A fronto‐parietal circuit for object manipulation in man: evidence from an fMRI‐study

TLDR

The study proposes that area SII processes intrinsic object characteristics while the superior parietal lobule encodes kinaesthetic information during object manipulation. Functional MRI was employed to identify brain regions engaged when subjects manipulated complex objects versus simple spheres and when covertly naming objects versus non‑recognizable ones. Complex object manipulation activated ventral premotor cortex BA44, intraparietal sulcus, area SII, and superior parietal lobule, with covert naming adding opercular BA44 and pars triangularis BA45, supporting a fronto‑parietal circuit for manipulation analogous to that in monkeys.

Abstract

Abstract Functional magnetic resonance imaging (fMRI) was used to localize brain areas active during manipulation of complex objects. In one experiment subjects were required to manipulate complex objects for exploring their macrogeometric features as compared to manipulation of a simple smooth object (a sphere). In a second experiment subjects were asked to manipulate complex objects and to silently name them upon recognition as compared to manipulation of complex not recognizable objects without covert naming. Manipulation of complex objects resulted in an activation of ventral premotor cortex [Brodmann's area (BA) 44], of a region in the intraparietal sulcus (most probably corresponding to the anterior intraparietal area in the monkey), of area SII and of a sector of the superior parietal lobule. When the objects were covertly named additional activations were found in the opercular part of BA 44 and in the pars triangularis of the inferior frontal gyrus (BA 45). We suggest that a fronto‐parietal circuit for manipulation of objects exists in humans and involves basically the same areas as in the monkey. It is proposed that area SII analyses the intrinsic object characteristics whilst the superior parietal lobule is related to kinaesthesia.