Event:

Our modern civilization provides a huge number of tools, which have been optimized for a specific purpose and goal. Some of these tools and their ways of usage are well known to each adult even if they have little practical experience with a respective tool. The integration of such highly familiar tools in sensorimotor and cognitive processing and planning can thus not only draw on currently available sensory information but also on long-term procedural and semantic memories associated with these tools. A so-called cortical tool network, consisting of the dorsal supramarginal gyrus (SMG), the inferior frontal cortex (IFC), and the inferior lateral occipito-temporal cortex (LOCT) has already been associated with the visual presentation, naming, and usage of tools. However, it is unknown through which structures or connections this tool network interacts with memory retrieval, thereby integrating semantic knowledge about tools. In three fMRI experiments comparing the processing of familiar with unfamiliar tools we found signal increases in the SMG, IFC, LOTC for unfamiliar tools relative to familiar tools, most likely associated with visual and sensorimotor analysis of a currently presented tool. Additionally, we found signal changes at the anterior fronto-median cortex, a region which is associated with decision-making and error monitoring. Signals in the posterior middle temporal gyrus suggested a specific role for this region in the retrieval of previously established knowledge about such tools. We assume that the posterior MTG connects long-term knowledge with ongoing motor cognition processing, representing a crucial hub in the integration of procedural and semantic memory, visual analysis, and motor cognition. This assumption has been supported by fMRI experiments using event-boundary detection paradigms and free viewing of natural movies and resting state fMRI analyses in large populations.