Tool perception suppresses 10-12Hz μ rhythm of EEG over the somatosensory area.

The perception of tools vs. other objects has been shown to activate the premotor (BA6) and somatosensory cortex (BA3), which neurally represent object affordance related to tool manipulability (Proverbio et al., 2011). The earliest tool/non-tool discrimination is represented by increased anterior negativity (210-270ms) in response to tools. In this study, we analyzed μ desynchronization with wavelet analysis based on EEG recordings in response to 300 familiar objects vs. tools in 11 participants. The results showed an early 140-175ms μ desynchronization over centro-parietal sites at approximately 10-12Hz during tool perception. The surface scalp distribution of μ power is compatible with neural generators located in the somatosensory cortex, but no source analysis was performed. These results support the hypothesis that there is a temporal and functional relationship between the rapid and transient μ suppression over the centro/parietal area and the successive increase in time-locked post-synaptic potentials (ERPs) in regions processing tool motor affordance.