Model-free detection of synchrony in neuronal spike trains, with an application to primate somatosensory cortex

Synchronized neuronal ring has been reported in many neural systems and may play a role in the representation of sensory stimuli and the modi cation of sensory representations by both experience and attention. In this report we describe a bootstrap procedure for computing the statistical signi cance of changes in the degree of synchrony and apply it to recordings from the second somatosensory (SII) cortex of Macaques performing tactile and visual discrimination tasks. A majority (68%) of neuron pairs in SII re synchronously in response to a tactile stimulus. In a fraction of those pairs (17.5%), the degree of synchrony covaries with the focus of attention.