Cognitive load as a determinant of the dimensionality of the electroencephalogram: a replication study

A sequel study to that reported by Gregson, Britton, Campbell and Gates (1990), partially replicating and extending findings which relate estimates of the dimensionality of the EEG to the complexity of task load in a visual scanning task, is described. The correlation dimensionality D2 of the attractor was computed using a variant of the Grassberger-Procaccia algorithm, and was shown to change in the expected direction, increasing as the task became more complicated. The effects are slight but consistent, and may be attenuated by nonstationarity over time, and by idiosyncratic factors. The results are numerically and qualitatively compatible with other recent reported studies, and support an interpretation linking brain dynamics to implied cognitive processes.