There is growing evidence that primary sensory cortices receive inputs from multiple modalities and activity in these areas can be modulated in a variety of ways by non-primary activity. Recent data show that somatosensory input amplifies auditory responses by resetting ongoing
neural oscillations in superficial layers of A1 to a high-excitability phase. Our objective was to examine the inverse of this effect in primary somatosensory cortex, and to describe the physiology of somatosensory-auditory interaction mechanisms across area 3B’s cortical laminae. Our data show the presence of nominal interactions in superficial cortical layers with relatively high levels of somatosensory stimulation. According to the principle of inverse effectiveness, and the previous pattern reported in auditory cortex, we predict that these interactions should be stronger with reduced intensity, as multisensory interactions are stronger when unisensory stimulation evokes weaker responses. We are currently looking at auditory-somatosensory interactions at reduced somatosensory intensities. These putative findings combined with our initial results show that primary somatosensory cortex operatively integrates auditory input and that neuronal oscillations play a key role in its multi-modal operations.