Sleep Spindles as an Electrographic Element: Description and Automatic Detection Methods

Figure 3

Fast and slow sleep spindles. (a) Average frequency of spindles across depth electrodes ( electrodes in 13 individuals). The color of each circle denotes the mean spindle frequency in an individual electrode according to its precise anatomical location. Green outlines mark electrodes placed more laterally than the midline. The two outliers in the medial prefrontal cortex (red circles) were the only electrode placements in one atypical individual in whom parietal spindles may be even faster than 13.5 Hz. (b) Quantitative analysis of time offsets in spindle occurrence. A graph showing the order in which spindles are detected across multiple regions (node color) and the mean temporal delays within each pair of regions (edge color). Mean order and timing across spindles for all individuals () indicate that centroparietal spindles precede frontal spindles. Orbitofrontal cortex (OF), anterior cingulate cortex (AC), posterior cingulate cortex (PC), presupplementary motor area (pSMA), and supplementary motor area (MSA). Modified from [30].

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